Profiling perf with perf revealed that a large part of the processing time is
spent in malloc/memcpy/free in the sample ordering code. That code copies the
data from the mmap into malloc'ed memory. That's silly. We can keep the mmap
and just store the pointer in the queuing data structure. For 64 bit this is
not a problem as we map the whole file anyway. On 32bit we keep 8 maps around
and unmap the oldest before mmaping the next chunk of the file.

Performance gain: 2.95s -> 1.23s (Faktor 2.4)

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.278787719@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

On 64bit we can map the whole file in one go, on 32bit we can at least map
32MB and not map/unmap tiny chunks of the file.

Base the progress bar on 1/16 of the data size.

Preparatory patch to get rid of the malloc/memcpy/free of trace data.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.213687773@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

No need to check twice.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.152886642@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The progress bar is changed when the file offset changes. This happens only
when the next mmap is done. No need to call ui_progress_update() for every
event.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.094836523@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Replace the pseudo C++ self argument with session and give the mmap related
variables a sensible name. shift is a complete misnomer - it took me several
rounds of cursing to figure out that it's not a shift value.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163820.029687218@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

There is no reason to use a struct sample_event pointer in struct sample_queue
and type cast it when flushing the queue.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163819.969462809@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The homebrewn sort algorithm fails to sort in time order. One of the problem
spots is that it fails to deal with equal timestamps correctly.

My first gut reaction was to replace the fancy list with an rbtree, but the
performance is 3 times worse.

Rewrite it so it works.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101130163819.908482530@linutronix.de>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

PERF_SAMPLE_{CALLCHAIN,RAW} have variable lenghts per sample, but the others
can be precalculated, reducing a bit the per sample cost.
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Fix it by explaining what can be happening and giving the number of processed
and lost events.

Also holler if unknown events were found, that can be due to processing a
perf.data file collected using a newer tool where newer events got added on
reporting using an older perf tool, that or a bug, so ask for a report to be
made.

Works on both --tui and --stdio.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Some filesystems like xfs and reiserfs will return DT_UNKNOWN for the
d_type.  Handle this case by calling stat() to determine the type.

Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290355779-3276-1-git-send-email-sbohrer@rgmadvisors.com>
Signed-off-by: NShawn Bohrer <sbohrer@rgmadvisors.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

If a 32bit userspace perf is running on a 64bit kernel, the end of the final
map in the kernel would incorrectly be set to 2^32-1 rather than 2^64-1.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290658375-10342-1-git-send-email-imunsie@au1.ibm.com>
Signed-off-by: NIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Tool developers have to fill in a 'perf_event_ops' method table to
specify how to handle each event, so far the ones that were not
explicitely especified would get a stub that would just discard the
event.

Change that so that tool developers can get the lost event details and
the total number of such events at the end of 'perf report -D' output.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
CC: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Collecting build-ids for long running sessions may take a long time
because it needs to traverse the whole just collected perf.data stream
of events, marking the DSOs that had hits and then looking for the
.note.gnu.build-id ELF section.

For things like the 'trace' tool that records and right away consumes
the data on systems where its unlikely that the DSOs being monitored
will change while 'trace' runs, it is desirable to remove build id
collection, so add a -B/--no-buildid option to perf record to allow such
use case.

Longer term we'll avoid all this if we, at DSO load time, in the kernel,
take advantage of this slow code path to collect the build-id and stash
it somewhere, so that we can insert it in the PERF_RECORD_MMAP event.
Reported-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Add description of .config in a sake of RAW events.
At least this should bring some light to those who
will be reading this code.
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: NStephane Eranian <eranian@google.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The perf hardware pmu got initialized at various points in the boot,
some before early_initcall() some after (notably arch_initcall).

The problem is that the NMI lockup detector is ran from early_initcall()
and expects the hardware pmu to be present.

Sanitize this by moving all architecture hardware pmu implementations to
initialize at early_initcall() and move the lockup detector to an explicit
initcall right after that.

Cc: paulus <paulus@samba.org>
Cc: davem <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Acked-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290707759.2145.119.camel@laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When booting up a CPU set the various topology masks before
calling the CPU_STARTING notifier. This way the notifier
can actually use the masks.

This is needed for a perf change.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290077254-12165-2-git-send-email-andi@firstfloor.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Some arch implementations call perf_event_overflow() by 'accident',
ignore this.
Reported-by: NFrancis Moreau <francis.moro@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290525705-6265-3-git-send-email-fbuihuu@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290525705-6265-2-git-send-email-fbuihuu@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

and use it when appropriate.
Signed-off-by: NFranck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290525705-6265-1-git-send-email-fbuihuu@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Make tags find the trace-event definitions
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
LKML-Reference: <1290591835.2072.438.camel@laptop>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Conflicts:
	arch/x86/kernel/apic/hw_nmi.c

Merge reason: Resolve conflict, queue up dependent patch.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge reason: Pick up latest fixes.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Stephane noticed that because the perf_sw_event() call is inside the
perf_event_task_sched_out() call it won't get called unless we
have a per-task counter.
Reported-by: NStephane Eranian <eranian@google.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

This leads to a Kconfig dep inversion, x86 selects PERF_EVENT (due to
a hw_breakpoint dep) but doesn't unconditionally provide
HAVE_PERF_EVENT.

(This can cause build failures on M386/M486 kernel .config's.)
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222055.982965150@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

In a kvm virt guests, the perf counters are not emulated.  Instead they
return zero on a rdmsrl. The perf nmi handler uses the fact that crossing
a zero means the counter overflowed (for those counters that do not have
specific interrupt bits). Therefore on kvm guests, perf will swallow all
NMIs thinking the counters overflowed.

This causes problems for subsystems like kgdb which needs NMIs to do its
magic. This problem was discovered by running kgdb tests.

The solution is to write garbage into a perf counter during the
initialization and hopefully reading back the same number.  On kvm
guests, the value will be read back as zero and we disable perf as
a result.
Reported-by: NJason Wessel <jason.wessel@windriver.com>
Patch-inspired-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NDon Zickus <dzickus@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <1290462923-30734-1-git-send-email-dzickus@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

It was found that sometimes children of tasks with inherited events had
one extra event. Eventually it turned out to be due to the list rotation
no being exclusive with the list iteration in the inheritance code.

Cure this by temporarily disabling the rotation while we inherit the events.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

perf bench: Add feature that measures the performance of the arch/x86/lib/memcpy_64.S memcpy routines via 'perf bench mem'

This patch ports arch/x86/lib/memcpy_64.S to perf bench mem
memcpy for benchmarking memcpy() in userland with tricky and
dirty way.

util/include/asm/cpufeature.h, util/include/asm/dwarf2.h, and
util/include/linux/linkage.h are mostly dummy files with small
wrappers, so that we are able to include memcpy_64.S
unmodified.
Signed-off-by: NHitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: h.mitake@gmail.com
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ma Ling <ling.ma@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <1290668693-27068-2-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

After applying this patch, perf bench mem memcpy prints
both of prefualted and without prefaulted score of memcpy().

New options --no-prefault and --only-prefault are added
to print single result, mainly for scripting usage.

Usage example:

 | mitake@X201i:~/linux/.../tools/perf% ./perf bench mem memcpy -l 500MB
 | # Running mem/memcpy benchmark...
 | # Copying 500MB Bytes ...
 |
 |      634.969014 MB/Sec
 |        4.828062 GB/Sec (with prefault)
 | mitake@X201i:~/linux/.../tools/perf% ./perf bench mem memcpy -l 500MB --only-prefault
 | # Running mem/memcpy benchmark...
 | # Copying 500MB Bytes ...
 |
 |        4.705192 GB/Sec (with prefault)
 | mitake@X201i:~/linux/.../tools/perf% ./perf bench mem memcpy -l 500MB --no-prefault
 | # Running mem/memcpy benchmark...
 | # Copying 500MB Bytes ...
 |
 |      642.725568 MB/Sec
Signed-off-by: NHitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: h.mitake@gmail.com
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ma Ling <ling.ma@intel.com>
Cc: Zhao Yakui <yakui.zhao@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andi Kleen <andi@firstfloor.org>
LKML-Reference: <1290668693-27068-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

At least on ARM, padding is inserted between rb_node and sym in struct
symbol_name_rb_node, causing "((void *)sym) - sizeof(struct rb_node)" to
point inside rb_node rather than to the symbol_name_rb_node.  Fix this
by converting the code to use container_of().

Cc: Ian Munsie <imunsie@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20101123163106.GA25677@debian>
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The 59365d13 commit, even being reverted by 33e0d57f, showed a non robust
behavior in 'perf record': it really should just warn the user that some
functionality will not be available.

The new behavior then becomes:

	[acme@felicio linux]$ ls -la /proc/{kallsyms,modules}
	-r-------- 1 root root 0 Nov 22 12:19 /proc/kallsyms
	-r-------- 1 root root 0 Nov 22 12:19 /proc/modules
	[acme@felicio linux]$ perf record ls -R > /dev/null
	Couldn't record kernel reference relocation symbol
	Symbol resolution may be skewed if relocation was used (e.g. kexec).
	Check /proc/kallsyms permission or run as root.
	[ perf record: Woken up 1 times to write data ]
	[ perf record: Captured and wrote 0.004 MB perf.data (~161 samples) ]
	[acme@felicio linux]$ perf report --stdio
	[kernel.kallsyms] with build id 77b05e00e64e4de1c9347d83879779b540d69f00 not found, continuing without symbols
	# Events: 98  cycles
	#
	# Overhead  Command    Shared Object                Symbol
	# ........  .......  ...............  ....................
	#
	    48.26%       ls  [kernel]         [k] ffffffff8102b92b
	    22.49%       ls  libc-2.12.90.so  [.] __strlen_sse2
	     8.35%       ls  libc-2.12.90.so  [.] __GI___strcoll_l
	     8.17%       ls  ls               [.]            11580
	     3.35%       ls  libc-2.12.90.so  [.] _IO_new_file_xsputn
	     3.33%       ls  libc-2.12.90.so  [.] _int_malloc
	     1.88%       ls  libc-2.12.90.so  [.] _int_free
	     0.84%       ls  libc-2.12.90.so  [.] malloc_consolidate
	     0.84%       ls  libc-2.12.90.so  [.] __readdir64
	     0.83%       ls  ls               [.] strlen@plt
	     0.83%       ls  libc-2.12.90.so  [.] __GI_fwrite_unlocked
	     0.83%       ls  libc-2.12.90.so  [.] __memcpy_sse2

	#
	# (For a higher level overview, try: perf report --sort comm,dso)
	#
[acme@felicio linux]$

It still has the build-ids for DSOs in the maps with hits:

[acme@felicio linux]$ perf buildid-list
77b05e00e64e4de1c9347d83879779b540d69f00 [kernel.kallsyms]
09c4a431a4a8b648fcfc2c2bdda70f56050ddff1 /bin/ls
af75ea9ad951d25e0f038901a11b3846dccb29a4 /lib64/libc-2.12.90.so
[acme@felicio linux]$

That can be used in another machine to resolve kernel symbols.

Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jesper Juhl <jj@chaosbits.net>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This patch makes several changes to "perf stat":

- "perf stat" will no longer go ahead and run the application when one or
more of the specified events could not be opened.
- Use error() and die() instead of pr_err() so that the output is more
consistent with "perf top" and "perf record".
- Handle permission errors in a more robust way, and in a similar way to
"perf record" and "perf top".

In addition, the sys_perf_event_open() error handling of "perf top" and "perf
record" is made more consistent and adds the following phrase when an event
doesn't open (with something ther than an access or permission error):

"/bin/dmesg may provide additional information."

This is added because kernel code doesn't have a good way of expressing
detailed errors to user space, so its only avenue is to use printk's.  However,
many users may not think of looking at dmesg to find out why an event is being
rejected.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <fweisbec@gmail.com>
Cc: Ian Munsie <ianmunsi@au1.ibm.com>
Cc: Michael Ellerman <michaele@au1.ibm.com>
LKML-Reference: <1290217044-26293-1-git-send-email-cjashfor@linux.vnet.ibm.com>
Signed-off-by: NCorey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard
  fs: Do not dispatch FITRIM through separate super_operation
  ext4: ext4_fill_super shouldn't return 0 on corruption
  jbd2: fix /proc/fs/jbd2/<dev> when using an external journal
  ext4: missing unlock in ext4_clear_request_list()
  ext4: fix setting random pages PageUptodate

Filesystem independent ioctl was rejected as not common enough to be in
core vfs ioctl. Since we still need to access to this functionality this
commit adds ext4 specific ioctl EXT4_IOC_TRIM to dispatch
ext4_trim_fs().

It takes fstrim_range structure as an argument. fstrim_range is definec in
the include/linux/fs.h and its definition is as follows.

struct fstrim_range {
	__u64 start;
	__u64 len;
	__u64 minlen;
}

start	- first Byte to trim
len	- number of Bytes to trim from start
minlen	- minimum extent length to trim, free extents shorter than this
  number of Bytes will be ignored. This will be rounded up to fs
  block size.

After the FITRIM is done, the number of actually discarded Bytes is stored
in fstrim_range.len to give the user better insight on how much storage
space has been really released for wear-leveling.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

There was concern that FITRIM ioctl is not common enough to be included
in core vfs ioctl, as Christoph Hellwig pointed out there's no real point
in dispatching this out to a separate vector instead of just through
->ioctl.

So this commit removes ioctl_fstrim() from vfs ioctl and trim_fs
from super_operation structure.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: fix readdir EOVERFLOW on 32-bit archs
  ceph: fix frag offset for non-leftmost frags
  ceph: fix dangling pointer
  ceph: explicitly specify page alignment in network messages
  ceph: make page alignment explicit in osd interface
  ceph: fix comment, remove extraneous args
  ceph: fix update of ctime from MDS
  ceph: fix version check on racing inode updates
  ceph: fix uid/gid on resent mds requests
  ceph: fix rdcache_gen usage and invalidate
  ceph: re-request max_size if cap auth changes
  ceph: only let auth caps update max_size
  ceph: fix open for write on clustered mds
  ceph: fix bad pointer dereference in ceph_fill_trace
  ceph: fix small seq message skipping
  Revert "ceph: update issue_seq on cap grant"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (31 commits)
  net: fix kernel-doc for sk_filter_rcu_release
  be2net: Fix to avoid firmware update when interface is not open.
  netfilter: fix IP_VS dependencies
  net: irda: irttp: sync error paths of data- and udata-requests
  ipv6: Expose reachable and retrans timer values as msecs
  ipv6: Expose IFLA_PROTINFO timer values in msecs instead of jiffies
  3c59x: fix build failure on !CONFIG_PCI
  ipg.c: remove id [SUNDANCE, 0x1021]
  net: caif: spi: fix potential NULL dereference
  ath9k_htc: Avoid setting QoS control for non-QoS frames
  net: zero kobject in rx_queue_release
  net: Fix duplicate volatile warning.
  MAINTAINERS: Add stmmac maintainer
  bonding: fix a race in IGMP handling
  cfg80211: fix can_beacon_sec_chan, reenable HT40
  gianfar: fix signedness issue
  net: bnx2x: fix error value sign
  8139cp: fix checksum broken
  r8169: fix checksum broken
  rds: Integer overflow in RDS cmsg handling
  ...

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_via: apply magic FIFO fix to vt6420 too

This reverts commit 59365d13.

It turns out that this can break certain existing user land setups.
Quoth Sarah Sharp:

 "On Wednesday, I updated my branch to commit 460781b5 from linus' tree,
  and my box would not boot.  klogd segfaulted, which stalled the whole
  system.

  At first I thought it actually hung the box, but it continued booting
  after 5 minutes, and I was able to log in.  It dropped back to the
  text console instead of the graphical bootup display for that period
  of time.  dmesg surprisingly still works.  I've bisected the problem
  down to this commit (commit 59365d13)

  The box is running klogd 1.5.5ubuntu3 (from Jaunty).  Yes, I know
  that's old.  I read the bit in the commit about changing the
  permissions of kallsyms after boot, but if I can't boot that doesn't
  help."

So let's just keep the old default, and encourage distributions to do
the "chmod -r /proc/kallsyms" in their bootup scripts.  This is not
worth a kernel option to change default behavior, since it's so easily
done in user space.
Reported-and-bisected-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcus Meissner <meissner@suse.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Eugene Teo <eugeneteo@kernel.org>
Cc: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>