Lockdep events subsystem gathers various locking related events
such as a request, release, contention or acquisition of a lock.
The name of this event subsystem is a bit of a misnomer since
these events are not quite related to lockdep but more generally
to locking, ie: these events are not reporting lock dependencies
or possible deadlock scenario but pure locking events.
Hence this rename.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <1258103194-843-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Some architectures (e.g. Alpha) do not support the
-fstack-protector-all compiler option and the use of the option
with -Werror causes the compiler to abort and the build fails.
Test that the compiler supports -fstack-protector-all before
inclusion in CFLAGS.
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091111074302.GA3728@omega>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Build a set of section headers for features right after the
datas. Each implemented feature will have one of such section
header that provides the offset and the size of the data
manipulated by the feature.
The trace informations have moved after the data and are
recorded on exit time.
The new layout is as follows:
-----------------------
___
[ magic ] |
[ header size ] |
[ attr size ] |
[ attr content offset ] |
[ attr content size ] |
[ data offset ] File Headers
[ data size ] |
[ event_types offset ] |
[ event_types size ] |
[ feature bitmap ] v
[ attr section ]
[ events section ]
___
[ X ] |
[ X ] |
[ X ] Datas
[ X ] |
[ X ] v
___
[ Feature 1 offset ] |
[ Feature 1 size ] Features headers
[ Feature 2 offset ] |
[ Feature 2 size ] v
[ Feature 1 content ]
[ Feature 2 content ]
-----------------------
We have as many feature's section headers as we have features in
use for the current file.
Say Feat 1 and Feat 3 are used by the file, but not Feat 2. Then
the feature headers will be like follows:
[ Feature 1 offset ] |
[ Feature 1 size ] Features headers
[ Feature 3 offset ] |
[ Feature 3 size ] v
There is no hole to cover Feature 2 that is not in use here. We
only need to cover the needed headers in order, from the lowest
feature bit to the highest.
Currently we have two features: HEADER_TRACE_INFO and
HEADER_BUILD_ID. Both have their contents that follow the
feature headers. Putting the contents right after the feature
headers is not mandatory though. While we keep the feature
headers right after the data and in order, their offsets can
point everywhere. We have just put the two above feature
contents in the end of the file for convenience.
The purpose of this layout change is to have a file format that
scales while keeping it simple: having such linear feature
headers is less error prone wrt forward/backward compatibility
as the content of a feature can be put anywhere, its location
can even change by the time, it's fine because its headers will
tell where it is. And we know how to find these headers,
following the above rules.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-6-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
We are saving the build id once we stop the profiling. And only
after doing that we know if we need to set that feature in the
header through the feature bitmap.
But if we want a proper feature support in the headers, using a
rule of offset/size pairs in sections, we need to know in
advance how many features we need to set in the headers, so that
we can reserve rooms for their section headers.
The current state doesn't allow that, as it forces us to first
save the build-ids to the file right after the datas instead of
planning any structured layout.
That's why this splits up the build-ids processing in two parts:
one that fetches the build-ids from the Dso objects, and one
that saves them into the file.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
LKML-Reference: <1257911467-28276-3-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
modify perf.c get_debugfs_mntpnt() to use the util/debugfs.c
debugfs_find_mountpoint()
modify util/parse-events.c to use debugfs_valid_mountpoint().
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091101155720.624cc87e@torg>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add routines to locate the debugfs mount point and to manage the
mounting and unmounting of the debugfs.
Signed-off-by: Clark Williams <williams@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20091101155621.2b3503ee@torg>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With this change 'perf record' will intercept PERF_RECORD_MMAP
calls, creating a linked list of DSOs, then when the session
finishes, it will traverse this list and read the buildids,
stashing them at the end of the file and will set up a new
feature bit in the header bitmask.
'perf report' will then notice this feature and populate the
'dsos' list and set the build ids.
When reading the symtabs it will refuse to load from a file that
doesn't have the same build id. This improves the
reliability of the profiler output, as symbols and profiling
data is more guaranteed to match.
Example:
[root@doppio ~]# perf report | head
/home/acme/bin/perf with build id b1ea544ac3746e7538972548a09aadecc5753868 not found, continuing without symbols
# Samples: 2621434559
#
# Overhead Command Shared Object Symbol
# ........ ............... ............................. ......
#
7.91% init [kernel] [k] read_hpet
7.64% init [kernel] [k] mwait_idle_with_hints
7.60% swapper [kernel] [k] read_hpet
7.60% swapper [kernel] [k] mwait_idle_with_hints
3.65% init [kernel] [k] 0xffffffffa02339d9
[root@doppio ~]#
In this case the 'perf' binary was an older one, vanished,
so its symbols probably wouldn't match or would cause subtly
different (and misleading) output.
Next patches will support the kernel as well, reading the build
id notes for it and the modules from /sys.
Another patch should also introduce a new plumbing command:
'perf list-buildids'
that will then be used in porcelain that is distro specific to
fetch -debuginfo packages where such buildids are present. This
will in turn allow for one to run 'perf record' in one machine
and 'perf report' in another.
Future work on having the buildid sent directly from the kernel
in the PERF_RECORD_MMAP event is needed to close races, as the
DSO can be changed during a 'perf record' session, but this
patch at least helps with non-corner cases and current/older
kernels.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: K. Prasad <prasad@linux.vnet.ibm.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1257367843-26224-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
tools/perf/Makefile
Merge reason: Resolve the conflict, merge to upstream and merge in
perf fixes so we can add a dependent patch.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://github.com/at91linux/linux-2.6-at91:
at91: at91sam9g45 family: identify several chip versions
avr32: add two new at91 to cpu.h definition
cpu_is_xxx() macros are identifying generic at91sam9g45 chip. This patch adds
the capacity to differentiate Engineering Samples and final lots through the
inclusion of at91_cpu_fully_identify() and the related chip IDs with chip
version field preserved.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Somme common drivers will need those at91 cpu_is_xxx() definitions. As
at91sam9g10 and at91sam9g45 are on the way to linus' tree, here is the patch
that adds those chips to cpu.h in AVR32 architecture.
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus: (38 commits)
MIPS: O32: Fix ppoll
MIPS: Oprofile: Rename cpu_type from godson2 to loongson2
MIPS: Alchemy: Fix hang with high-frequency edge interrupts
MIPS: TXx9: Fix spi-baseclk value
MIPS: bcm63xx: Set the correct BCM3302 CPU name
MIPS: Loongson 2: Set cpu_has_dc_aliases and cpu_icache_snoops_remote_store
MIPS: Avoid potential hazard on Context register
MIPS: Octeon: Use lockless interrupt controller operations when possible.
MIPS: Octeon: Use write_{un,}lock_irq{restore,save} to set irq affinity
MIPS: Set S-cache linesize to 64-bytes for MTI's S-cache
MIPS: SMTC: Avoid queing multiple reschedule IPIs
MIPS: GCMP: Avoid accessing registers when they are not present
MIPS: GIC: Random fixes and enhancements.
MIPS: CMP: Fix memory barriers for correct operation of amon_cpu_start
MIPS: Fix abs.[sd] and neg.[sd] emulation for NaN operands
MIPS: SPRAM: Clean up support code a little
MIPS: 1004K: Enable SPRAM support.
MIPS: Malta: Enable PCI 2.1 compatibility in PIIX4
MIPS: Kconfig: Fix duplicate default value for MIPS_L1_CACHE_SHIFT.
MIPS: MTI: Fix accesses to device registers on MIPS boards
...
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM: Remove some debug messages producing too much noise
PM: Fix warning on suspend errors
PM / Hibernate: Add newline to load_image() fail path
PM / Hibernate: Fix error handling in save_image()
PM / Hibernate: Fix blkdev refleaks
PM / yenta: Split resume into early and late parts (rev. 4)
nr_processes() returns the sum of the per cpu counter process_counts for
all online CPUs. This counter is incremented for the current CPU on
fork() and decremented for the current CPU on exit(). Since a process
does not necessarily fork and exit on the same CPU the process_count for
an individual CPU can be either positive or negative and effectively has
no meaning in isolation.
Therefore calculating the sum of process_counts over only the online
CPUs omits the processes which were started or stopped on any CPU which
has since been unplugged. Only the sum of process_counts across all
possible CPUs has meaning.
The only caller of nr_processes() is proc_root_getattr() which
calculates the number of links to /proc as
stat->nlink = proc_root.nlink + nr_processes();
You don't have to be all that unlucky for the nr_processes() to return a
negative value leading to a negative number of links (or rather, an
apparently enormous number of links). If this happens then you can get
failures where things like "ls /proc" start to fail because they got an
-EOVERFLOW from some stat() call.
Example with some debugging inserted to show what goes on:
# ps haux|wc -l
nr_processes: CPU0: 90
nr_processes: CPU1: 1030
nr_processes: CPU2: -900
nr_processes: CPU3: -136
nr_processes: TOTAL: 84
proc_root_getattr. nlink 12 + nr_processes() 84 = 96
84
# echo 0 >/sys/devices/system/cpu/cpu1/online
# ps haux|wc -l
nr_processes: CPU0: 85
nr_processes: CPU2: -901
nr_processes: CPU3: -137
nr_processes: TOTAL: -953
proc_root_getattr. nlink 12 + nr_processes() -953 = -941
75
# stat /proc/
nr_processes: CPU0: 84
nr_processes: CPU2: -901
nr_processes: CPU3: -137
nr_processes: TOTAL: -954
proc_root_getattr. nlink 12 + nr_processes() -954 = -942
File: `/proc/'
Size: 0 Blocks: 0 IO Block: 1024 directory
Device: 3h/3d Inode: 1 Links: 4294966354
Access: (0555/dr-xr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2009-11-03 09:06:55.000000000 +0000
Modify: 2009-11-03 09:06:55.000000000 +0000
Change: 2009-11-03 09:06:55.000000000 +0000
I'm not 100% convinced that the per_cpu regions remain valid for offline
CPUs, although my testing suggests that they do. If not then I think the
correct solution would be to aggregate the process_count for a given CPU
into a global base value in cpu_down().
This bug appears to pre-date the transition to git and it looks like it
may even have been present in linux-2.6.0-test7-bk3 since it looks like
the code Rusty patched in http://lwn.net/Articles/64773/ was already
wrong.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: gpio-keys - use IRQF_SHARED
Input: winbond-cir - select LEDS_TRIGGERS
Input: i8042 - try to get stable CTR value when initializing
Input: atkbd - add a quirk for OQO 01+ multimedia keys
Frederic Weisbecker
Hiroshi Shimamoto
Michael Cree
Zeev Tarantov
Clark Williams
Arnaldo Carvalho de Melo
Ingo Molnar
Linus Torvalds
Nicolas Ferre
Thiago Farina
Ian Campbell