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steelman and others added 30 commits March 30, 2015 10:05
Signed-off-by: Łukasz Stelmach <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
This patch just sorts IDs in the table for better maintenance. There is no
functional change.

Signed-off-by: Andy Shevchenko <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
gpio_defaults needs to be specified as an unsigned int rather than an
int, because the intention of the DT binding is that all out of range
values for a 16-bit register will cause the defaults to be used,
however, if gpio_defaults is an int then values that are larger than
INT_MAX will become negative numbers and be written out directly to the
hardware. As no where in the code replies on gpio_defaults being an int,
the simplest fix is to just change it to unsigned.

Signed-off-by: Charles Keepax <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Delete unused macro.

Signed-off-by: Aaro Koskinen <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Drop support for SW controlled VCORE, nobody uses it.

Signed-off-by: Aaro Koskinen <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Use macro to check a register bit.

Signed-off-by: Aaro Koskinen <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Replace duplicated const keyword for 'axp20x_model_names' with proper
array of const pointers to const strings.

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
…PMI PMIC's

Some of the PMIC's could have specific regmap configuration
tables in future, so add specific compatible strings for known
PMIC's. Also print runtime detected chip revision information.

Signed-off-by: Ivan T. Ivanov <[email protected]>
Acked-by: Stephen Boyd <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
This is a I2C driver, so it's wrong to use platform prefix for the
modalias. We have all needed i2c aliases coming form MODULE_DEVICE_TABLE,
so let's remove the wrong and unneeded "platform:twl6040" modalias.

Signed-off-by: Axel Lin <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
Disabling libbabeltrace check by default and replacing the
NO_LIBBABELTRACE make variable with LIBBABELTRACE.

Users wanting the libbabeltrace feature need to build via:

  $ make LIBBABELTRACE=1

The reason for this is that the libababeltrace interface we use (version
1.3) hasn't been packaged/released yet, thus the failing feature check
only slows down build and confuses other (non CTF) developers.

Requested-by: Ingo Molnar <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Acked-by: Ingo Molnar <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jeremie Galarneau <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sebastian Andrzej Siewior <[email protected]>
Cc: Tom Zanussi <[email protected]>
Cc: Wang Nan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
debugfs_create_dir and debugfs_create_file may return -ENODEV when debugfs
is not configured, so the return value should be checked against ERROR_VALUE
as well, otherwise the later dereference of the dentry pointer would crash
the kernel.

Signed-off-by: Chengyu Song <[email protected]>
Signed-off-by: Bob Peterson <[email protected]>
Acked-by: Steven Whitehouse <[email protected]>
iovec-backed iov_iter instances are assumed to satisfy several properties:
	* no more than UIO_MAXIOV elements in iovec array
	* total size of all ranges is no more than MAX_RW_COUNT
	* all ranges pass access_ok().

The problem is, invariants of data structures should be established in the
primitives creating those data structures, not in the code using those
primitives.  And iov_iter_init() violates that principle.  For a while we
managed to get away with that, but once the use of iov_iter started to
spread, it didn't take long for shit to hit the fan - missed check in
sys_sendto() had introduced a roothole.

We _do_ have primitives for importing and validating iovecs (both native and
compat ones) and those primitives are almost always followed by shoving the
resulting iovec into iov_iter.  Life would be considerably simpler (and safer)
if we combined those primitives with initializing iov_iter.

That gives us two new primitives - import_iovec() and compat_import_iovec().
Calling conventions:
	iovec = iov_array;
	err = import_iovec(direction, uvec, nr_segs,
			   ARRAY_SIZE(iov_array), &iovec,
			   &iter);
imports user vector into kernel space (into iov_array if it fits, allocated
if it doesn't fit or if iovec was NULL), validates it and sets iter up to
refer to it.  On success 0 is returned and allocated kernel copy (or NULL
if the array had fit into caller-supplied one) is returned via iovec.
On failure all allocations are undone and -E... is returned.  If the total
size of ranges exceeds MAX_RW_COUNT, the excess is silently truncated.

compat_import_iovec() expects uvec to be a pointer to user array of compat_iovec;
otherwise it's identical to import_iovec().

Finally, import_single_range() sets iov_iter backed by single-element iovec
covering a user-supplied range -

	err = import_single_range(direction, address, size, iovec, &iter);

does validation and sets iter up.  Again, size in excess of MAX_RW_COUNT gets
silently truncated.

Next commits will be switching the things up to use of those and reducing
the amount of iov_iter_init() instances.

Signed-off-by: Al Viro <[email protected]>
A clean up of the recursive protection code changed

  val = this_cpu_read(current_context);
  val--;
  val &= this_cpu_read(current_context);

to

  val = this_cpu_read(current_context);
  val &= val & (val - 1);

Which has a duplicate use of '&' as the above is the same as

  val = val & (val - 1);

Actually, it would be best to remove that line altogether and
just add it to where it is used.

And Christoph even mentioned that it can be further compacted to
just a single line:

  __this_cpu_and(current_context, __this_cpu_read(current_context) - 1);

Link: http://lkml.kernel.org/[email protected]

Suggested-by: Christoph Lameter <[email protected]>
Signed-off-by: Steven Rostedt <[email protected]>
Commit 2e77784 ("perf callchain: Move cpumode resolve code to
add_callchain_ip") promised "No change in behavior.".

As this commit breaks callchains on s390x (symbols not getting resolved,
observed when profiling the kernel), this statement is wrong. The cpumode
must be kept when iterating over all ips, otherwise the default
(PERF_RECORD_MISC_USER) will be used by error.

Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Hendrik Brueckner <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Rather than parsing /proc/pid/status file one line at a time, read it
into a buffer in one shot and search for all strings in one pass.

tgid conversion also simplified -- removing the isspace walk. As noted
by Arnaldo those are not needed for atoi == strtol calls.

Signed-off-by: David Ahern <[email protected]>
Acked-by: Don Zickus <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Joe Mario <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
363b785 added synthesized fork events and set a thread's parent id to
itself. Since we are already processing /proc/<pid>/status the ppid can
be determined properly. Make it so.

Signed-off-by: David Ahern <[email protected]>
Acked-by: Don Zickus <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Joe Mario <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Even when it is not used to actually reorder events, some of its fields
are used, like session->ordered_events->tool, to shorten function
signatures where tool, for instance, was being passed, as the tool is
needed for the ordered_events code, we need it there and might as well
use it for other perf_session needs.

This fixes a problem where 'perf script' had some condition that made
session->ordered_events not to be initialized even with its
script->tool ordered_events related flags asking for it to be, which
looks like another bug and needs to be investigated further.

Always initializing session->ordered_events at least leaves the current
assumptions in place, so do it now.

Reported-by: David Ahern <[email protected]>
Reviewed-by: David Ahern <[email protected]>
Tested-by: David Ahern <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
…hines

As these can be obtained from the ordered_events pointer, via
container_of, reducing the cross section of ordered_samples.

These were added to ordered_samples in:

 commit b7b61cb
 Author: Arnaldo Carvalho de Melo <[email protected]>
 Date:   Tue Mar 3 11:58:45 2015 -0300

    perf ordered_events: Shorten function signatures

    By keeping pointers to machines, evlist and tool in ordered_events.

But that was more a transitional patch while moving stuff out from
perf_session.c to ordered_events.c and possibly not even needed by then,
as we could use the container_of() method and instead of having the
nr_unordered_samples stats in events_stats, we can have it in
ordered_samples.

Based-on-a-patch-by: Jiri Olsa <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Don Zickus <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Eliminate redundant calculations by performing millisecond to jiffy
calculations once during driver initialization.

Signed-off-by: Aaron Sierra <[email protected]>
Signed-off-by: Dmitry Torokhov <[email protected]>
…/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

 - Fix 'perf script' pipe mode segfault, by always initializing ordered_events in
   perf_session__new(). (Arnaldo Carvalho de Melo)

 - Fix ppid for synthesized fork events. (David Ahern)

 - Fix kernel symbol resolution of callchains in S/390 by remembering the
   cpumode. (David Hildenbrand)

Infrastructure changes:

 - Disable libbabeltrace check by default in the build system. (Jiri Olsa)

Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
This WIP branch is now ready to be merged.

Signed-off-by: Ingo Molnar <[email protected]>
Socket filter code and other subsystems with upcoming eBPF
support should not need to deal with the fact that we have
CONFIG_BPF_SYSCALL defined or not.

Having the bpf syscall as a config option is a nice thing and
I'd expect it to stay that way for expert users (I presume one
day the default setting of it might change, though), but code
making use of it should not care if it's actually enabled or
not.

Instead, hide this via header files and let the rest deal with it.

Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
add TRACE_EVENT_FL_KPROBE flag to differentiate kprobe type of
tracepoints, since bpf programs can only be attached to kprobe
type of PERF_TYPE_TRACEPOINT perf events.

Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Steven Rostedt <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
BPF programs, attached to kprobes, provide a safe way to execute
user-defined BPF byte-code programs without being able to crash or
hang the kernel in any way. The BPF engine makes sure that such
programs have a finite execution time and that they cannot break
out of their sandbox.

The user interface is to attach to a kprobe via the perf syscall:

	struct perf_event_attr attr = {
		.type	= PERF_TYPE_TRACEPOINT,
		.config	= event_id,
		...
	};

	event_fd = perf_event_open(&attr,...);
	ioctl(event_fd, PERF_EVENT_IOC_SET_BPF, prog_fd);

'prog_fd' is a file descriptor associated with BPF program
previously loaded.

'event_id' is an ID of the kprobe created.

Closing 'event_fd':

	close(event_fd);

... automatically detaches BPF program from it.

BPF programs can call in-kernel helper functions to:

  - lookup/update/delete elements in maps

  - probe_read - wraper of probe_kernel_read() used to access any
    kernel data structures

BPF programs receive 'struct pt_regs *' as an input ('struct pt_regs' is
architecture dependent) and return 0 to ignore the event and 1 to store
kprobe event into the ring buffer.

Note, kprobes are a fundamentally _not_ a stable kernel ABI,
so BPF programs attached to kprobes must be recompiled for
every kernel version and user must supply correct LINUX_VERSION_CODE
in attr.kern_version during bpf_prog_load() call.

Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Steven Rostedt <[email protected]>
Reviewed-by: Masami Hiramatsu <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
bpf_ktime_get_ns() is used by programs to compute time delta
between events or as a timestamp

Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Steven Rostedt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Debugging of BPF programs needs some form of printk from the
program, so let programs call limited trace_printk() with %d %u
%x %p modifiers only.

Similar to kernel modules, during program load verifier checks
whether program is calling bpf_trace_printk() and if so, kernel
allocates trace_printk buffers and emits big 'this is debug
only' banner.

Signed-off-by: Alexei Starovoitov <[email protected]>
Reviewed-by: Steven Rostedt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
tracex1_kern.c - C program compiled into BPF.

It attaches to kprobe:netif_receive_skb()

When skb->dev->name == "lo", it prints sample debug message into
trace_pipe via bpf_trace_printk() helper function.

tracex1_user.c - corresponding user space component that:
  - loads BPF program via bpf() syscall
  - opens kprobes:netif_receive_skb event via perf_event_open()
    syscall
  - attaches the program to event via ioctl(event_fd,
    PERF_EVENT_IOC_SET_BPF, prog_fd);
  - prints from trace_pipe

Note, this BPF program is non-portable. It must be recompiled
with current kernel headers. kprobe is not a stable ABI and
BPF+kprobe scripts may no longer be meaningful when kernel
internals change.

No matter in what way the kernel changes, neither the kprobe,
nor the BPF program can ever crash or corrupt the kernel,
assuming the kprobes, perf and BPF subsystem has no bugs.

The verifier will detect that the program is using
bpf_trace_printk() and the kernel will print 'this is a DEBUG
kernel' warning banner, which means that bpf_trace_printk()
should be used for debugging of the BPF program only.

Usage:
$ sudo tracex1
            ping-19826 [000] d.s2 63103.382648: : skb ffff880466b1ca00 len 84
            ping-19826 [000] d.s2 63103.382684: : skb ffff880466b1d300 len 84

            ping-19826 [000] d.s2 63104.382533: : skb ffff880466b1ca00 len 84
            ping-19826 [000] d.s2 63104.382594: : skb ffff880466b1d300 len 84

Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
…the write() syscall

this example has two probes in one C file that attach to
different kprove events and use two different maps.

1st probe is x64 specific equivalent of dropmon. It attaches to
kfree_skb, retrevies 'ip' address of kfree_skb() caller and
counts number of packet drops at that 'ip' address. User space
prints 'location - count' map every second.

2nd probe attaches to kprobe:sys_write and computes a histogram
of different write sizes

Usage:
	$ sudo tracex2
	location 0xffffffff81695995 count 1
	location 0xffffffff816d0da9 count 2

	location 0xffffffff81695995 count 2
	location 0xffffffff816d0da9 count 2

	location 0xffffffff81695995 count 3
	location 0xffffffff816d0da9 count 2

	557145+0 records in
	557145+0 records out
	285258240 bytes (285 MB) copied, 1.02379 s, 279 MB/s
		   syscall write() stats
	     byte_size       : count     distribution
	       1 -> 1        : 3        |                                      |
	       2 -> 3        : 0        |                                      |
	       4 -> 7        : 0        |                                      |
	       8 -> 15       : 0        |                                      |
	      16 -> 31       : 2        |                                      |
	      32 -> 63       : 3        |                                      |
	      64 -> 127      : 1        |                                      |
	     128 -> 255      : 1        |                                      |
	     256 -> 511      : 0        |                                      |
	     512 -> 1023     : 1118968  |************************************* |

Ctrl-C at any time. Kernel will auto cleanup maps and programs

	$ addr2line -ape ./bld_x64/vmlinux 0xffffffff81695995
	0xffffffff816d0da9 0xffffffff81695995:
	./bld_x64/../net/ipv4/icmp.c:1038 0xffffffff816d0da9:
	./bld_x64/../net/unix/af_unix.c:1231

Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
BPF C program attaches to
blk_mq_start_request()/blk_update_request() kprobe events to
calculate IO latency.

For every completed block IO event it computes the time delta
in nsec and records in a histogram map:

	map[log10(delta)*10]++

User space reads this histogram map every 2 seconds and prints
it as a 'heatmap' using gray shades of text terminal. Black
spaces have many events and white spaces have very few events.
Left most space is the smallest latency, right most space is
the largest latency in the range.

Usage:

	$ sudo ./tracex3
	and do 'sudo dd if=/dev/sda of=/dev/null' in other terminal.

Observe IO latencies and how different activity (like 'make
kernel') affects it.

Similar experiments can be done for network transmit latencies,
syscalls, etc.

'-t' flag prints the heatmap using normal ascii characters:

$ sudo ./tracex3 -t
  heatmap of IO latency
  # - many events with this latency
    - few events
	|1us      |10us     |100us    |1ms      |10ms     |100ms    |1s |10s
				 *ooo. *O.#.                                    # 221
			      .  *#     .                                       # 125
				 ..   .o#*..                                    # 55
			    .  . .  .  .#O                                      # 37
				 .#                                             # 175
				       .#*.                                     # 37
				  #                                             # 199
		      .              . *#*.                                     # 55
				       *#..*                                    # 42
				  #                                             # 266
			      ...***Oo#*OO**o#* .                               # 629
				  #                                             # 271
				      . .#o* o.*o*                              # 221
				. . o* *#O..                                    # 50

Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
One BPF program attaches to kmem_cache_alloc_node() and
remembers all allocated objects in the map.
Another program attaches to kmem_cache_free() and deletes
corresponding object from the map.

User space walks the map every second and prints any objects
which are older than 1 second.

Usage:

	$ sudo tracex4

Then start few long living processes. The 'tracex4' will print
something like this:

	obj 0xffff880465928000 is 13sec old was allocated at ip ffffffff8105dc32
	obj 0xffff88043181c280 is 13sec old was allocated at ip ffffffff8105dc32
	obj 0xffff880465848000 is  8sec old was allocated at ip ffffffff8105dc32
	obj 0xffff8804338bc280 is 15sec old was allocated at ip ffffffff8105dc32

	$ addr2line -fispe vmlinux ffffffff8105dc32
	do_fork at fork.c:1665

As soon as processes exit the memory is reclaimed and 'tracex4'
prints nothing.

Similar experiment can be done with the __kmalloc()/kfree() pair.

Signed-off-by: Alexei Starovoitov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
paulmck and others added 26 commits April 13, 2015 08:25
Currently, smpboot_unpark_threads() is invoked before the incoming CPU
has been added to the scheduler's runqueue structures.  This might
potentially cause the unparked kthread to run on the wrong CPU, since the
correct CPU isn't fully set up yet.

That causes a sporadic, hard to debug boot crash triggering on some
systems, reported by Borislav Petkov, and bisected down to:

  2a442c9 ("x86: Use common outgoing-CPU-notification code")

This patch places smpboot_unpark_threads() in a CPU hotplug
notifier with priority set so that these kthreads are unparked just after
the CPU has been added to the runqueues.

Reported-and-tested-by: Borislav Petkov <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Now that we are using smpboot_thread_init() in init/main.c as well,
provide it for !CONFIG_SMP as well.

This addresses a !CONFIG_SMP build failure.

Cc: Paul E. McKenney <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>
…uion-uclogic-merge', 'for-4.1/i2c-hid', 'for-4.1/kconfig-drop-expert-dependency', 'for-4.1/logitech', 'for-4.1/multitouch', 'for-4.1/rmi', 'for-4.1/sony', 'for-4.1/upstream' and 'for-4.1/wacom' into for-linus
Conflicts:
	drivers/iio/common/hid-sensors/hid-sensor-trigger.c
	include/linux/hid-sensor-hub.h
Prepare first round of input updates for 4.1 merge window.
…/git/jikos/hid

Pull HID updates from Jiri Kosina:

 - quite a few firmware fixes for RMI driver by Andrew Duggan

 - huion and uclogic drivers have been substantially overlaping in
   functionality laterly.  This redundancy is fixed by hid-huion driver
   being merged into hid-uclogic; work done by Benjamin Tissoires and
   Nikolai Kondrashov

 - i2c-hid now supports ACPI GPIO interrupts; patch from Mika Westerberg

 - Some of the quirks, that got separated into individual drivers, have
   historically had EXPERT dependency.  As HID subsystem matured (as
   well as the individual drivers), this made less and less sense.  This
   dependency is now being removed by patch from Jean Delvare

 - Logitech lg4ff driver received a couple of improvements for mode
   switching, by Michal Malý

 - multitouch driver now supports clickpads, patches by Benjamin
   Tissoires and Seth Forshee

 - hid-sensor framework received a substantial update; namely support
   for Custom and Generic pages is being added; work done by Srinivas
   Pandruvada

 - wacom driver received substantial update; it now supports
   i2c-conntected devices (Mika Westerberg), Bamboo PADs are now
   properly supported (Benjamin Tissoires), much improved battery
   reporting (Jason Gerecke) and pen proximity cleanups (Ping Cheng)

 - small assorted fixes and device ID additions

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (68 commits)
  HID: sensor: Update document for custom sensor
  HID: sensor: Custom and Generic sensor support
  HID: debug: fix error handling in hid_debug_events_read()
  Input - mt: Fix input_mt_get_slot_by_key
  HID: logitech-hidpp: fix error return code
  HID: wacom: Add support for Cintiq 13HD Touch
  HID: logitech-hidpp: add a module parameter to keep firmware gestures
  HID: usbhid: yet another mouse with ALWAYS_POLL
  HID: usbhid: more mice with ALWAYS_POLL
  HID: wacom: set stylus_in_proximity before checking touch_down
  HID: wacom: use wacom_wac_finger_count_touches to set touch_down
  HID: wacom: remove hardcoded WACOM_QUIRK_MULTI_INPUT
  HID: pidff: effect can't be NULL
  HID: add quirk for PIXART OEM mouse used by HP
  HID: add HP OEM mouse to quirk ALWAYS_POLL
  HID: wacom: ask for a in-prox report when it was missed
  HID: hid-sensor-hub: Fix sparse warning
  HID: hid-sensor-hub: fix attribute read for logical usage id
  HID: plantronics: fix Kconfig default
  HID: pidff: support more than one concurrent effect
  ...
…/git/jikos/trivial

Pull trivial tree from Jiri Kosina:
 "Usual trivial tree updates.  Nothing outstanding -- mostly printk()
  and comment fixes and unused identifier removals"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
  goldfish: goldfish_tty_probe() is not using 'i' any more
  powerpc: Fix comment in smu.h
  qla2xxx: Fix printks in ql_log message
  lib: correct link to the original source for div64_u64
  si2168, tda10071, m88ds3103: Fix firmware wording
  usb: storage: Fix printk in isd200_log_config()
  qla2xxx: Fix printk in qla25xx_setup_mode
  init/main: fix reset_device comment
  ipwireless: missing assignment
  goldfish: remove unreachable line of code
  coredump: Fix do_coredump() comment
  stacktrace.h: remove duplicate declaration task_struct
  smpboot.h: Remove unused function prototype
  treewide: Fix typo in printk messages
  treewide: Fix typo in printk messages
  mod_devicetable: fix comment for match_flags
…/git/jikos/livepatching

Pull livepatching updates from Jiri Kosina:
 "These are mostly smaller things that got accumulated during the
  development cycle.  The unified solution is still being worked on and
  is not mature enough for 4.1 yet.

   - s390 livepatching support, from Jiri Slaby (has Ack from s390
     maintainers)

   - error handling simplification, from Josh Poimboeuf

   - two minor code cleanups from Josh Poimboeuf and Miroslav Benes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: add support on s390
  livepatch: remove unnecessary call to klp_find_object_module()
  livepatch: simplify disable error path
  livepatch: remove extern specifier from header files
…ernel/git/rostedt/linux-trace

Pull tracefs from Steven Rostedt:
 "This adds the new tracefs file system.

  This has been in linux-next for more than one release, as I had it
  ready for the 4.0 merge window, but a last minute thing that needed to
  go into Linux first had to be done.  That was that perf hard coded the
  file system number when reading /sys/kernel/debugfs/tracing directory
  making sure that the path had the debugfs mount # before it would
  parse the tracing file.  This broke other use cases of perf, and the
  check is removed.

  Now when mounting /sys/kernel/debug, tracefs is automatically mounted
  in /sys/kernel/debug/tracing such that old tools will still see that
  path as expected.  But now system admins can mount tracefs directly
  and not need to mount debugfs, which can expose security issues.  A
  new directory is created when tracefs is configured such that system
  admins can now mount it separately (/sys/kernel/tracing)"

* tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have mkdir and rmdir be part of tracefs
  tracefs: Add directory /sys/kernel/tracing
  tracing: Automatically mount tracefs on debugfs/tracing
  tracing: Convert the tracing facility over to use tracefs
  tracefs: Add new tracefs file system
  tracing: Create cmdline tracer options on tracing fs init
  tracing: Only create tracer options files if directory exists
  debugfs: Provide a file creation function that also takes an initial size
…it/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "Some clean ups and small fixes, but the biggest change is the addition
  of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints.

  Tracepoints have helper functions for the TP_printk() called
  __print_symbolic() and __print_flags() that lets a numeric number be
  displayed as a a human comprehensible text.  What is placed in the
  TP_printk() is also shown in the tracepoint format file such that user
  space tools like perf and trace-cmd can parse the binary data and
  express the values too.  Unfortunately, the way the TRACE_EVENT()
  macro works, anything placed in the TP_printk() will be shown pretty
  much exactly as is.  The problem arises when enums are used.  That's
  because unlike macros, enums will not be changed into their values by
  the C pre-processor.  Thus, the enum string is exported to the format
  file, and this makes it useless for user space tools.

  The TRACE_DEFINE_ENUM() solves this by converting the enum strings in
  the TP_printk() format into their number, and that is what is shown to
  user space.  For example, the tracepoint tlb_flush currently has this
  in its format file:

     __print_symbolic(REC->reason,
        { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" },
        { TLB_REMOTE_SHOOTDOWN, "remote shootdown" },
        { TLB_LOCAL_SHOOTDOWN, "local shootdown" },
        { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" })

  After adding:

     TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH);
     TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN);
     TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN);

  Its format file will contain this:

     __print_symbolic(REC->reason,
        { 0, "flush on task switch" },
        { 1, "remote shootdown" },
        { 2, "local shootdown" },
        { 3, "local mm shootdown" })"

* tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits)
  tracing: Add enum_map file to show enums that have been mapped
  writeback: Export enums used by tracepoint to user space
  v4l: Export enums used by tracepoints to user space
  SUNRPC: Export enums in tracepoints to user space
  mm: tracing: Export enums in tracepoints to user space
  irq/tracing: Export enums in tracepoints to user space
  f2fs: Export the enums in the tracepoints to userspace
  net/9p/tracing: Export enums in tracepoints to userspace
  x86/tlb/trace: Export enums in used by tlb_flush tracepoint
  tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM()
  tracing: Allow for modules to convert their enums to values
  tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values
  tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation
  tracing: Give system name a pointer
  brcmsmac: Move each system tracepoints to their own header
  iwlwifi: Move each system tracepoints to their own header
  mac80211: Move message tracepoints to their own header
  tracing: Add TRACE_SYSTEM_VAR to xhci-hcd
  tracing: Add TRACE_SYSTEM_VAR to kvm-s390
  tracing: Add TRACE_SYSTEM_VAR to intel-sst
  ...
…ux/kernel/git/tip/tip

Pull RCU changes from Ingo Molnar:
 "The main changes in this cycle were:

   - changes permitting use of call_rcu() and friends very early in
     boot, for example, before rcu_init() is invoked.

   - add in-kernel API to enable and disable expediting of normal RCU
     grace periods.

   - improve RCU's handling of (hotplug-) outgoing CPUs.

   - NO_HZ_FULL_SYSIDLE fixes.

   - tiny-RCU updates to make it more tiny.

   - documentation updates.

   - miscellaneous fixes"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  cpu: Provide smpboot_thread_init() on !CONFIG_SMP kernels as well
  cpu: Defer smpboot kthread unparking until CPU known to scheduler
  rcu: Associate quiescent-state reports with grace period
  rcu: Yet another fix for preemption and CPU hotplug
  rcu: Add diagnostics to grace-period cleanup
  rcutorture: Default to grace-period-initialization delays
  rcu: Handle outgoing CPUs on exit from idle loop
  cpu: Make CPU-offline idle-loop transition point more precise
  rcu: Eliminate ->onoff_mutex from rcu_node structure
  rcu: Process offlining and onlining only at grace-period start
  rcu: Move rcu_report_unblock_qs_rnp() to common code
  rcu: Rework preemptible expedited bitmask handling
  rcu: Remove event tracing from rcu_cpu_notify(), used by offline CPUs
  rcutorture: Enable slow grace-period initializations
  rcu: Provide diagnostic option to slow down grace-period initialization
  rcu: Detect stalls caused by failure to propagate up rcu_node tree
  rcu: Eliminate empty HOTPLUG_CPU ifdef
  rcu: Simplify sync_rcu_preempt_exp_init()
  rcu: Put all orphan-callback-related code under same comment
  rcu: Consolidate offline-CPU callback initialization
  ...
…linux/kernel/git/tip/tip

Pull NOHZ changes from Ingo Molnar:
 "This tree adds full dynticks support to KVM guests (support the
  disabling of the timer tick on the guest).  The main missing piece was
  the recognition of guest execution as RCU extended quiescent state and
  related changes"

* 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kvm,rcu,nohz: use RCU extended quiescent state when running KVM guest
  context_tracking: Export context_tracking_user_enter/exit
  context_tracking: Run vtime_user_enter/exit only when state == CONTEXT_USER
  context_tracking: Add stub context_tracking_is_enabled
  context_tracking: Generalize context tracking APIs to support user and guest
  context_tracking: Rename context symbols to prepare for transition state
  ppc: Remove unused cpp symbols in kvm headers
…nux/kernel/git/tip/tip

Pull perf changes from Ingo Molnar:
 "Core kernel changes:

   - One of the more interesting features in this cycle is the ability
     to attach eBPF programs (user-defined, sandboxed bytecode executed
     by the kernel) to kprobes.

     This allows user-defined instrumentation on a live kernel image
     that can never crash, hang or interfere with the kernel negatively.
     (Right now it's limited to root-only, but in the future we might
     allow unprivileged use as well.)

     (Alexei Starovoitov)

   - Another non-trivial feature is per event clockid support: this
     allows, amongst other things, the selection of different clock
     sources for event timestamps traced via perf.

     This feature is sought by people who'd like to merge perf generated
     events with external events that were measured with different
     clocks:

       - cluster wide profiling

       - for system wide tracing with user-space events,

       - JIT profiling events

     etc.  Matching perf tooling support is added as well, available via
     the -k, --clockid <clockid> parameter to perf record et al.

     (Peter Zijlstra)

  Hardware enablement kernel changes:

   - x86 Intel Processor Trace (PT) support: which is a hardware tracer
     on steroids, available on Broadwell CPUs.

     The hardware trace stream is directly output into the user-space
     ring-buffer, using the 'AUX' data format extension that was added
     to the perf core to support hardware constraints such as the
     necessity to have the tracing buffer physically contiguous.

     This patch-set was developed for two years and this is the result.
     A simple way to make use of this is to use BTS tracing, the PT
     driver emulates BTS output - available via the 'intel_bts' PMU.
     More explicit PT specific tooling support is in the works as well -
     will probably be ready by 4.2.

     (Alexander Shishkin, Peter Zijlstra)

   - x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
     feature of Intel Xeon CPUs that allows the measurement and
     allocation/partitioning of caches to individual workloads.

     These kernel changes expose the measurement side as a new PMU
     driver, which exposes various QoS related PMU events.  (The
     partitioning change is work in progress and is planned to be merged
     as a cgroup extension.)

     (Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
     Waskiewicz Jr)

   - x86 Intel Haswell LBR call stack support: this is a new Haswell
     feature that allows the hardware recording of call chains, plus
     tooling support.  To activate this feature you have to enable it
     via the new 'lbr' call-graph recording option:

        perf record --call-graph lbr
        perf report

     or:

        perf top --call-graph lbr

     This hardware feature is a lot faster than stack walk or dwarf
     based unwinding, but has some limitations:

       - It reuses the current LBR facility, so LBR call stack and
         branch record can not be enabled at the same time.

       - It is only available for user-space callchains.

     (Yan, Zheng)

   - x86 Intel Broadwell CPU support and various event constraints and
     event table fixes for earlier models.

     (Andi Kleen)

   - x86 Intel HT CPUs event scheduling workarounds.  This is a complex
     CPU bug affecting the SNB,IVB,HSW families that results in counter
     value corruption.  The mitigation code is automatically enabled and
     is transparent.

     (Maria Dimakopoulou, Stephane Eranian)

  The perf tooling side had a ton of changes in this cycle as well, so
  I'm only able to list the user visible changes here, in addition to
  the tooling changes outlined above:

  User visible changes affecting all tools:

      - Improve support of compressed kernel modules (Jiri Olsa)
      - Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
      - Bash completion for subcommands (Yunlong Song)
      - Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
      - Support missing -f to override perf.data file ownership. (Yunlong Song)
      - Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)

  User visible changes in individual tools:

    'perf data':

        New tool for converting perf.data to other formats, initially
        for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
        Sebastian Siewior)

    'perf diff':

        Add --kallsyms option (David Ahern)

    'perf list':

        Allow listing events with 'tracepoint' prefix (Yunlong Song)

        Sort the output of the command (Yunlong Song)

    'perf kmem':

        Respect -i option (Jiri Olsa)

        Print big numbers using thousands' group (Namhyung Kim)

        Allow -v option (Namhyung Kim)

        Fix alignment of slab result table (Namhyung Kim)

    'perf probe':

        Support multiple probes on different binaries on the same command line (Masami Hiramatsu)

        Support unnamed union/structure members data collection. (Masami Hiramatsu)

        Check kprobes blacklist when adding new events. (Masami Hiramatsu)

    'perf record':

        Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)

        Support recording running/enabled time (Andi Kleen)

    'perf sched':

        Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)

    'perf report' and 'perf top':

        Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)

        Indicate which callchain entries are annotated in the
        TUI hists browser (Arnaldo Carvalho de Melo)

        Add pid/tid filtering to 'report' and 'script' commands (David Ahern)

        Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
        cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
        events (Arnaldo Carvalho de Melo)

    'perf stat':

        Report unsupported events properly (Suzuki K. Poulose)

        Output running time and run/enabled ratio in CSV mode (Andi Kleen)

    'perf trace':

        Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)

        Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)

        Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)

        Dump stack on segfaults (Arnaldo Carvalho de Melo)

        No need to explicitely enable evsels for workload started from perf, let it
        be enabled via perf_event_attr.enable_on_exec, removing some events that take
        place in the 'perf trace' before a workload is really started by it.
        (Arnaldo Carvalho de Melo)

        Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)

  There's also been a ton of infrastructure work done, such as the
  split-out of perf's build system into tools/build/ and other changes -
  see the shortlog and changelog for details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
  perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
  perf evlist: Fix type for references to data_head/tail
  perf probe: Check the orphaned -x option
  perf probe: Support multiple probes on different binaries
  perf buildid-list: Fix segfault when show DSOs with hits
  perf tools: Fix cross-endian analysis
  perf tools: Fix error path to do closedir() when synthesizing threads
  perf tools: Fix synthesizing fork_event.ppid for non-main thread
  perf tools: Add 'I' event modifier for exclude_idle bit
  perf report: Don't call map__kmap if map is NULL.
  perf tests: Fix attr tests
  perf probe: Fix ARM 32 building error
  perf tools: Merge all perf_event_attr print functions
  perf record: Add clockid parameter
  perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
  perf sched replay: Support using -f to override perf.data file ownership
  perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
  perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
  perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
  perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
  ...
…el/git/viro/vfs

Pull vfs update from Al Viro:
 "Part one:

   - struct filename-related cleanups

   - saner iov_iter_init() replacements (and switching the syscalls to
     use of those)

   - ntfs switch to ->write_iter() (Anton)

   - aio cleanups and splitting iocb into common and async parts
     (Christoph)

   - assorted fixes (me, bfields, Andrew Elble)

  There's a lot more, including the completion of switchover to
  ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
  race fixes, etc, but that goes after #for-davem merge.  David has
  pulled it, and once it's in I'll send the next vfs pull request"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
  sg_start_req(): use import_iovec()
  sg_start_req(): make sure that there's not too many elements in iovec
  blk_rq_map_user(): use import_single_range()
  sg_io(): use import_iovec()
  process_vm_access: switch to {compat_,}import_iovec()
  switch keyctl_instantiate_key_common() to iov_iter
  switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
  aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
  vmsplice_to_user(): switch to import_iovec()
  kill aio_setup_single_vector()
  aio: simplify arguments of aio_setup_..._rw()
  aio: lift iov_iter_init() into aio_setup_..._rw()
  lift iov_iter into {compat_,}do_readv_writev()
  NFS: fix BUG() crash in notify_change() with patch to chown_common()
  dcache: return -ESTALE not -EBUSY on distributed fs race
  NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
  VFS: Add iov_iter_fault_in_multipages_readable()
  drop bogus check in file_open_root()
  switch security_inode_getattr() to struct path *
  constify tomoyo_realpath_from_path()
  ...
…kernel/git/aegl/linux

Pull pstore fix from Tony Luck:
 "Just one pstore fix this release"

* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  pstore: Fix the ramoops module parameters update
Pull jfs update from David Kleikamp:
 "Not much this time. Just a one-liner format fix"

* tag 'jfs-4.1' of git://github.com/kleikamp/linux-shaggy:
  jfs: %pf is only for function pointers
…ernel/git/gfs2/linux-gfs2

Pull GFS2 updates from Bob Peterson:
 "Here is a list of patches we've accumulated for GFS2 for the current
  upstream merge window.

  Most of the patches fix GFS2 quotas, which were not properly enforced.
  There's another that adds me as a GFS2 co-maintainer, and a couple
  patches that fix a kernel panic doing splice_write on GFS2 as well as
  a few correctness patches"

* tag 'gfs2-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: fix quota refresh race in do_glock()
  gfs2: incorrect check for debugfs returns
  gfs2: allow fallocate to max out quotas/fs efficiently
  gfs2: allow quota_check and inplace_reserve to return available blocks
  gfs2: perform quota checks against allocation parameters
  GFS2: Move gfs2_file_splice_write outside of #ifdef
  GFS2: Allocate reservation during splice_write
  GFS2: gfs2_set_acl(): Cache "no acl" as well
  Add myself (Bob Peterson) as a maintainer of GFS2
Merge first patchbomb from Andrew Morton:

 - arch/sh updates

 - ocfs2 updates

 - kernel/watchdog feature

 - about half of mm/

* emailed patches from Andrew Morton <[email protected]>: (122 commits)
  Documentation: update arch list in the 'memtest' entry
  Kconfig: memtest: update number of test patterns up to 17
  arm: add support for memtest
  arm64: add support for memtest
  memtest: use phys_addr_t for physical addresses
  mm: move memtest under mm
  mm, hugetlb: abort __get_user_pages if current has been oom killed
  mm, mempool: do not allow atomic resizing
  memcg: print cgroup information when system panics due to panic_on_oom
  mm: numa: remove migrate_ratelimited
  mm: fold arch_randomize_brk into ARCH_HAS_ELF_RANDOMIZE
  mm: split ET_DYN ASLR from mmap ASLR
  s390: redefine randomize_et_dyn for ELF_ET_DYN_BASE
  mm: expose arch_mmap_rnd when available
  s390: standardize mmap_rnd() usage
  powerpc: standardize mmap_rnd() usage
  mips: extract logic for mmap_rnd()
  arm64: standardize mmap_rnd() usage
  x86: standardize mmap_rnd() usage
  arm: factor out mmap ASLR into mmap_rnd
  ...
…ernel/git/lee/mfd

Pull MFD updates from Lee Jones:
 "Changes to existing drivers:

   - Rename child driver [axp288_battery => axp288_fuel_gauge]; axp20x
   - Rename child driver [max77693-flash => max77693-led]; max77693
   - Error handling fixes; intel_soc_pmic
   - GPIO tweaking; intel_soc_pmic
   - Remove non-DT code; vexpress-sysreg, tc3589x
   - Remove unused/legacy code; ti_am335x_tscadc, rts5249, rtsx_gops, rtsx_pcr,
                                rtc-s5m, sec-core, max77693, menelaus,
                                wm5102-tables
   - Trivial fixups; rtsx_pci, da9150-core, sec-core, max7769, max77693,
                     mc13xxx-core, dln2, hi6421-pmic-core, rk808, twl4030-power,
                     lpc_ich, menelaus, twl6040
   - Update register/address values; rts5227, rts5249
   - DT and/or binding document fixups; arizona, da9150, mt6397, axp20x,
                                        qcom-rpm, qcom-spmi-pmic
   - Couple of trivial core Kconfig fixups
   - Remove use of seq_printf return value; ab8500-debugfs
   - Remove __exit markups; menelaus, tps65010
   - Fix platform-device name collisions; mfd-core

  New drivers/supported devices:

   - Add support for wm8280/wm8281 into arizona
   - Add support for COMe-cBL6 into kempld-core
   - Add support for rts524a and rts525a into rts5249
   - Add support for ipq8064 into qcom_rpm
   - Add support for extcon into axp20x
   - New MediaTek MT6397 PMIC driver
   - New Maxim MAX77843 PMIC dirver
   - New Intel Quark X1000 I2C-GPIO driver
   - New Skyworks SKY81452 driver"

* tag 'mfd-for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (76 commits)
  mfd: sec: Fix RTC alarm interrupt number on S2MPS11
  mfd: wm5102: Remove registers for output 3R from readable list
  mfd: tps65010: Remove incorrect __exit markups
  mfd: devicetree: bindings: Add Qualcomm RPM regulator subnodes
  mfd: axp20x: Add support for extcon cell
  mfd: lpc_ich: Sort IDs
  mfd: twl6040: Remove wrong and unneeded "platform:twl6040" modalias
  mfd: qcom-spmi-pmic: Add specific compatible strings for Qualcomm's SPMI PMIC's
  mfd: axp20x: Fix duplicate const for model names
  mfd: menelaus: Use macro for magic number
  mfd: menelaus: Drop support for SW controller VCORE
  mfd: menelaus: Delete omap_has_menelaus
  mfd: arizona: Correct type of gpio_defaults
  mfd: lpc_ich: Sort IDs
  mfd: Fix a typo in Kconfig
  mfd: qcom_rpm: Add support for IPQ8064
  mfd: devicetree: qcom_rpm: Document IPQ8064 resources
  mfd: core: Fix platform-device name collisions
  mfd: intel_quark_i2c_gpio: Don't crash if !DMI
  dt-bindings: Add vendor-prefix for X-Powers
  ...
…inux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
 "Changes to existing drivers:

   - Use of_get_child_by_name() instead of refcount; 88pm860x_bl

   - Terminate array with NULL element; da9052_bl"

* tag 'backlight-for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: da9052_bl: Terminate da9052_wled_ids array with empty element
  backlight: 88pm860x_bl: Use of_get_child_by_name() instead of refcount hack
…el/git/linusw/linux-pinctrl

Pull pincontrol updates from Linus Walleij:
 "This is the bulk of pin control changes for the v4.1 development
  cycle.  Nothing really exciting this time: we basically added a few
  new drivers and subdrivers and stabilized them in linux-next.  Some
  cleanups too.  With sunrisepoint Intel has a real fine fully featured
  pin control driver for contemporary hardware, and the AMD driver is
  also for large deployments.  Most of the others are ARM devices.

  New drivers:
    - Intel Sunrisepoint
    - AMD KERNCZ GPIO
    - Broadcom Cygnus IOMUX

  New subdrivers:
    - Marvell MVEBU Armada 39x SoCs
    - Samsung Exynos 5433
    - nVidia Tegra 210
    - Mediatek MT8135
    - Mediatek MT8173
    - AMLogic Meson8b
    - Qualcomm PM8916

  On top of this cleanups and development history for the above drivers
  as issues were fixed after merging"

* tag 'pinctrl-v4.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (71 commits)
  pinctrl: sirf: move sgpio lock into state container
  pinctrl: Add support for PM8916 GPIO's and MPP's
  pinctrl: bcm2835: Fix support for threaded level triggered IRQs
  sh-pfc: r8a7790: add EtherAVB pin groups
  pinctrl: Document "function" + "pins" pinmux binding
  pinctrl: intel: Add Intel Sunrisepoint pin controller and GPIO support
  pinctrl: fsl: imx: Check for 0 config register
  pinctrl: Add support for Meson8b
  documentation: Extend pinctrl docs for Meson8b
  pinctrl: Cleanup Meson8 driver
  Fix inconsistent spinlock of AMD GPIO driver which can be recognized by static analysis tool smatch. Declare constant Variables with Sparse's suggestion.
  pinctrl: at91: convert __raw to endian agnostic IO
  pinctrl: constify of_device_id array
  pinctrl: pinconf-generic: add dt node names to error messages
  pinctrl: pinconf-generic: scan also referenced phandle node
  pinctrl: mvebu: add suspend/resume support to Armada XP pinctrl driver
  pinctrl: st: Display pin's function when printing pinctrl debug information
  pinctrl: st: Show correct pin direction also in GPIO mode
  pinctrl: st: Supply a GPIO get_direction() call-back
  pinctrl: st: Move st_get_pio_control() further up the source file
  ...
Pull VFIO updates from Alex Williamson:

 - VFIO platform bus driver support (Baptiste Reynal, Antonios Motakis,
   testing and review by Eric Auger)

 - Split VFIO irqfd support to separate module (Alex Williamson)

 - vfio-pci VGA arbiter client (Alex Williamson)

 - New vfio-pci.ids= module option (Alex Williamson)

 - vfio-pci D3 power state support for idle devices (Alex Williamson)

* tag 'vfio-v4.1-rc1' of git://github.com/awilliam/linux-vfio: (30 commits)
  vfio-pci: Fix use after free
  vfio-pci: Move idle devices to D3hot power state
  vfio-pci: Remove warning if try-reset fails
  vfio-pci: Allow PCI IDs to be specified as module options
  vfio-pci: Add VGA arbiter client
  vfio-pci: Add module option to disable VGA region access
  vgaarb: Stub vga_set_legacy_decoding()
  vfio: Split virqfd into a separate module for vfio bus drivers
  vfio: virqfd_lock can be static
  vfio: put off the allocation of "minor" in vfio_create_group
  vfio/platform: implement IRQ masking/unmasking via an eventfd
  vfio: initialize the virqfd workqueue in VFIO generic code
  vfio: move eventfd support code for VFIO_PCI to a separate file
  vfio: pass an opaque pointer on virqfd initialization
  vfio: add local lock for virqfd instead of depending on VFIO PCI
  vfio: virqfd: rename vfio_pci_virqfd_init and vfio_pci_virqfd_exit
  vfio: add a vfio_ prefix to virqfd_enable and virqfd_disable and export
  vfio/platform: support for level sensitive interrupts
  vfio/platform: trigger an interrupt via eventfd
  vfio/platform: initial interrupts support code
  ...
…nel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "Most notable:

   - introducing the i2c_quirk infrastructure.  Now, flaws of I2C
     controllers can be described and the core will check if the flaws
     collide with the messages to be sent

   - wait_for_completion return type cleanup series

   - new drivers for Digicolor, Netlogic XLP, Ingenic JZ4780

   - updates to the I2C slave framework which include API changes.  Its
     only user was updated, too.  Documentation was finally added

   - changed dynamic bus numbering for the DT case.  This could change
     bus numbers for users.  However, it fixes a collision where dynamic
     and static busses request the same id.

   - driver bugfixes, cleanups"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (52 commits)
  i2c: xlp9xx: Driver for Netlogic XLP9XX/5XX I2C controller
  of: Add vendor prefix 'netlogic'
  i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery
  i2c: davinci: use bus recovery infrastructure
  i2c: change input parameter to i2c_adapter for prepare/unprepare_recovery
  i2c: i2c-mux-gpio: remove error messages for probe deferrals
  i2c: jz4780: Add i2c bus controller driver for Ingenic JZ4780
  i2c: dln2: set the device tree node of the adapter
  i2c: davinci: fixup wait_for_completion_timeout handling
  i2c: mpc: Fix ISR return value
  i2c: slave-eeprom: add more info when to increase the pointer
  i2c: slave: add documentation for i2c-slave-eeprom
  Documentation: i2c: describe the new slave mode
  i2c: slave: rework the slave API
  i2c: add support for the Digicolor I2C controller
  i2c: busses with dynamic ids should start after fixed ids for DT
  of: base: add function to get highest id of an alias stem
  i2c: designware: Suppress error message if platform_get_irq() < 0
  i2c: mpc: assign the correct prescaler from SVR
  i2c: img-scb: fixup of wait_for_completion_timeout return handling
  ...
…/git/dtor/input

Pull input subsystem updates from Dmitry Torokhov:
 "You will get the following new drivers:

   - Qualcomm PM8941 power key drver
   - ChipOne icn8318 touchscreen controller driver
   - Broadcom iProc touchscreen and keypad drivers
   - Semtech SX8654 I2C touchscreen controller driver

  ALPS driver now supports newer SS4 devices; Elantech got a fix that
  should make it work on some ASUS laptops; and a slew of other
  enhancements and random fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (51 commits)
  Input: alps - non interleaved V2 dualpoint has separate stick button bits
  Input: alps - fix touchpad buttons getting stuck when used with trackpoint
  Input: atkbd - document "no new force-release quirks" policy
  Input: ALPS - make alps_get_pkt_id_ss4_v2() and others static
  Input: ALPS - V7 devices can report 5-finger taps
  Input: ALPS - add support for SS4 touchpad devices
  Input: ALPS - refactor alps_set_abs_params_mt()
  Input: elantech - fix absolute mode setting on some ASUS laptops
  Input: atmel_mxt_ts - split out touchpad initialisation logic
  Input: atmel_mxt_ts - implement support for T100 touch object
  Input: cros_ec_keyb - fix clearing keyboard state on wakeup
  Input: gscps2 - drop pci_ids dependency
  Input: synaptics - allocate 3 slots to keep stability in image sensors
  Input: Revert "Revert "synaptics - use dmax in input_mt_assign_slots""
  Input: MT - make slot assignment work for overcovered solutions
  mfd: tc3589x: enforce device-tree only mode
  Input: tc3589x - localize platform data
  Input: tsc2007 - Convert msecs to jiffies only once
  Input: edt-ft5x06 - remove EV_SYN event report
  Input: edt-ft5x06 - allow to setting the maximum axes value through the DT
  ...
@linhphi9x94
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update

@ldts
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ldts commented Apr 15, 2015

please could you provide some more info.

@koenkooi koenkooi merged commit 8691c13 into 96boards:master Apr 15, 2015
johnstultz-work pushed a commit that referenced this pull request Jan 5, 2016
commit ecf5fc6 upstream.

Nikolay has reported a hang when a memcg reclaim got stuck with the
following backtrace:

PID: 18308  TASK: ffff883d7c9b0a30  CPU: 1   COMMAND: "rsync"
  #0 __schedule at ffffffff815ab152
  #1 schedule at ffffffff815ab76e
  #2 schedule_timeout at ffffffff815ae5e5
  #3 io_schedule_timeout at ffffffff815aad6a
  #4 bit_wait_io at ffffffff815abfc6
  #5 __wait_on_bit at ffffffff815abda5
  #6 wait_on_page_bit at ffffffff8111fd4f
  #7 shrink_page_list at ffffffff81135445
  #8 shrink_inactive_list at ffffffff81135845
  #9 shrink_lruvec at ffffffff81135ead
 #10 shrink_zone at ffffffff811360c3
 #11 shrink_zones at ffffffff81136eff
 #12 do_try_to_free_pages at ffffffff8113712f
 #13 try_to_free_mem_cgroup_pages at ffffffff811372be
 #14 try_charge at ffffffff81189423
 #15 mem_cgroup_try_charge at ffffffff8118c6f5
 #16 __add_to_page_cache_locked at ffffffff8112137d
 #17 add_to_page_cache_lru at ffffffff81121618
 #18 pagecache_get_page at ffffffff8112170b
 #19 grow_dev_page at ffffffff811c8297
 #20 __getblk_slow at ffffffff811c91d6
 #21 __getblk_gfp at ffffffff811c92c1
 #22 ext4_ext_grow_indepth at ffffffff8124565c
 #23 ext4_ext_create_new_leaf at ffffffff81246ca8
 #24 ext4_ext_insert_extent at ffffffff81246f09
 #25 ext4_ext_map_blocks at ffffffff8124a848
 #26 ext4_map_blocks at ffffffff8121a5b7
 #27 mpage_map_one_extent at ffffffff8121b1fa
 #28 mpage_map_and_submit_extent at ffffffff8121f07b
 #29 ext4_writepages at ffffffff8121f6d5
 #30 do_writepages at ffffffff8112c490
 #31 __filemap_fdatawrite_range at ffffffff81120199
 #32 filemap_flush at ffffffff8112041c
 #33 ext4_alloc_da_blocks at ffffffff81219da1
 #34 ext4_rename at ffffffff81229b91
 #35 ext4_rename2 at ffffffff81229e32
 #36 vfs_rename at ffffffff811a08a5
 #37 SYSC_renameat2 at ffffffff811a3ffc
 #38 sys_renameat2 at ffffffff811a408e
 #39 sys_rename at ffffffff8119e51e
 #40 system_call_fastpath at ffffffff815afa89

Dave Chinner has properly pointed out that this is a deadlock in the
reclaim code because ext4 doesn't submit pages which are marked by
PG_writeback right away.

The heuristic was introduced by commit e62e384 ("memcg: prevent OOM
with too many dirty pages") and it was applied only when may_enter_fs
was specified.  The code has been changed by c3b94f4 ("memcg:
further prevent OOM with too many dirty pages") which has removed the
__GFP_FS restriction with a reasoning that we do not get into the fs
code.  But this is not sufficient apparently because the fs doesn't
necessarily submit pages marked PG_writeback for IO right away.

ext4_bio_write_page calls io_submit_add_bh but that doesn't necessarily
submit the bio.  Instead it tries to map more pages into the bio and
mpage_map_one_extent might trigger memcg charge which might end up
waiting on a page which is marked PG_writeback but hasn't been submitted
yet so we would end up waiting for something that never finishes.

Fix this issue by replacing __GFP_IO by may_enter_fs check (for case 2)
before we go to wait on the writeback.  The page fault path, which is
the only path that triggers memcg oom killer since 3.12, shouldn't
require GFP_NOFS and so we shouldn't reintroduce the premature OOM
killer issue which was originally addressed by the heuristic.

As per David Chinner the xfs is doing similar thing since 2.6.15 already
so ext4 is not the only affected filesystem.  Moreover he notes:

: For example: IO completion might require unwritten extent conversion
: which executes filesystem transactions and GFP_NOFS allocations. The
: writeback flag on the pages can not be cleared until unwritten
: extent conversion completes. Hence memory reclaim cannot wait on
: page writeback to complete in GFP_NOFS context because it is not
: safe to do so, memcg reclaim or otherwise.

Cc: [email protected] # 3.9+
[[email protected]: corrected the control flow]
Fixes: c3b94f4 ("memcg: further prevent OOM with too many dirty pages")
Reported-by: Nikolay Borisov <[email protected]>
Signed-off-by: Michal Hocko <[email protected]>
Signed-off-by: Hugh Dickins <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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