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* tools/vm: Switch to liblk libraryBorislav Petkov2013-03-15
| | | | | | | | | | | | page-flags.c had some older version of debugfs_mount copied from perf so convert it to using the version in the tools library. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Link: http://lkml.kernel.org/r/1361374353-30385-8-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Extract perf-specific stuff from debugfs.cBorislav Petkov2013-03-15
| | | | | | | | | | Move them to util.c and simplify code a bit. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1361374353-30385-6-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Introduce tools/lib/lk libraryBorislav Petkov2013-03-15
| | | | | | | | | | | | | | | This introduces the tools/lib/lk library, that will gradually have the routines that now are used in tools/perf/ and other tools and that can be shared. Start by carving out debugfs routines for general use. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1361374353-30385-5-git-send-email-bp@alien8.de [ committer note: Add tools/lib/lk/ to perf's MANIFEST so that its tarballs continue to build ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tests: Add attr stat -C cpu testJiri Olsa2013-03-15
| | | | | | | | | | | | | | | | | Adding test to validate perf_event_attr data for command: 'stat -C 0' Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361785972-7431-6-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tests: Add attr record -C cpu testJiri Olsa2013-03-15
| | | | | | | | | | | | | | | | | Adding test to validate perf_event_attr data for command: 'record -C 0' Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361785972-7431-5-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tests: Make attr script test event cpuJiri Olsa2013-03-15
| | | | | | | | | | | | | | | | | | Make attr script to check for 'cpu' when testing event properties. This will allow us to check the '-C X' option for both record and stat commands. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361785972-7431-4-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tests: Make attr script verbose friendlyJiri Olsa2013-03-15
| | | | | | | | | | | | | | | | | | | | Making the attr test script runner to pass proper verbose option. Also making single '-v' be more reader friendly and display just the test name. Making the current output to be display for '-vv'. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361785972-7431-3-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Sort command-list.txt alphabeticallyliguang2013-03-15
| | | | | | | | | | | | Signed-off-by: liguang <lig.fnst@cn.fujitsu.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361851974-25307-1-git-send-email-lig.fnst@cn.fujitsu.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Correct Makefile.includeBorislav Petkov2013-03-15
| | | | | | | | | | | | | It looks at O= and adjusts the $(OUTPUT) variable based on what the output directory will be. However, when O is defined but empty, it wrongly becomes the user's $HOME dir which is not what we want. So check it is not empty before working with it further. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1361374353-30385-4-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Honor parallel jobsBorislav Petkov2013-03-15
| | | | | | | | | | | | | | We need to hand down parallel build options like the internal make --jobserver-fds one so that parallel builds can also happen when building perf from the toplevel directory. Make it so #1! Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1361374353-30385-3-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Remove a write-only variable in the debugfs codeBorislav Petkov2013-03-15
| | | | | | | | | | | debugfs_premounted is written-to only so drop it. This functionality is covered by debugfs_found now. Make it a bool while at it. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1361374353-30385-2-git-send-email-bp@alien8.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Fix build on non-glibc systems due to libio.h absenceCody P Schafer2013-03-15
| | | | | | | | | | | | | | | | | | | Including libio.h causes build failures on uClibc systems (which lack libio.h). It appears that libio.h was only included to pull in a definition for NULL, so it has been replaced by stddef.h. On powerpc, libio.h was conditionally included, but could be removed completely as it is unneeded. Also, the included of stdlib.h was changed to stddef.h (as again, only NULL is needed). Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1363300074-26288-1-git-send-email-cody@linux.vnet.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Fix LIBNUMA build with glibc 2.12 and older.Vinson Lee2013-03-14
| | | | | | | | | | | | | | | | | | | | | | | | | | The tokens MADV_HUGEPAGE and MADV_NOHUGEPAGE are not available with glibc 2.12 and older. Define these tokens if they are not already defined. This patch fixes these build errors with older versions of glibc. CC bench/numa.o bench/numa.c: In function ‘alloc_data’: bench/numa.c:334: error: ‘MADV_HUGEPAGE’ undeclared (first use in this function) bench/numa.c:334: error: (Each undeclared identifier is reported only once bench/numa.c:334: error: for each function it appears in.) bench/numa.c:341: error: ‘MADV_NOHUGEPAGE’ undeclared (first use in this function) make: *** [bench/numa.o] Error 1 Signed-off-by: Vinson Lee <vlee@twitter.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Irina Tirdea <irina.tirdea@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1363214064-4671-2-git-send-email-vlee@twitter.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf/POWER7: Create a sysfs format entry for Power7 eventsSukadev Bhattiprolu2013-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Create a sysfs entry, '/sys/bus/event_source/devices/cpu/format/event' which describes the format of the POWER7 PMU events. This code is based on corresponding code in x86. Changelog[v4]: [Michael Ellerman, Paul Mckerras] The event format is different for other POWER cpus. So move the code to POWER7-specific, power7-pmu.c Also, the POWER7 format uses bits 0-19 not 0-20. Changelog[v2]: [Jiri Osla] Use PMU_FORMAT_ATTR rather than duplicating code. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Tested-by: Michael Ellerman <michael@ellerman.id.au> Cc: Andi Kleen <ak@linux.intel.com> Cc: Anton Blanchard <anton@au1.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Michael Ellerman <michael@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Robert Richter <robert.richter@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: benh@kernel.crashing.org Cc: linuxppc-dev@ozlabs.org Link: http://lkml.kernel.org/r/20130306054826.GA14627@us.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe: Fix segfaultAnanth N Mavinakayanahalli2013-03-13
| | | | | | | | | | | Fix segfault in perf probe due to a bug introduced by commit d8639f068 (perf tools: Stop using 'self' in strlist). Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130312090217.GC4668@in.ibm.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* libtraceevent: Remove hard coded include to /usr/local/include in MakefileJack Mitchell2013-03-13
| | | | | | | | | | | | | | having /usr/local/include hardcoded into the makefile is not necessary as this is automatically included by GCC. It also infects cross-compile builds with the host systems includes. Signed-off-by: Jack Mitchell <jack.mitchell@dbbroadcast.co.uk> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1362741712-21308-1-git-send-email-ml@communistcode.co.uk Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf record: Fix -C optionJiri Olsa2013-03-13
| | | | | | | | | | | | | | | | | | | | | Currently the -C option does not work for record command, because of the targets mismatch when synthesizing threads. Fixing this by using proper target interface for the synthesize decision. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Reported-by: Oleg Nesterov <oleg@redhat.com> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361785972-7431-2-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: check if -DFORTIFY_SOURCE=2 is allowedMarcin Slusarz2013-03-13
| | | | | | | | | | | | | | | | | | | | | | It seems gcc (4.7.2) defines _FORTIFY_SOURCE internally and becomes confused when it sees another definition in flags. For me, build failed like this: CHK glibc Makefile:548: *** No gnu/libc-version.h found, please install glibc-dev[el]/glibc-static. Stop. and only with V=1 it printed: <command-line>:0:0: error: "_FORTIFY_SOURCE" redefined [-Werror] <stdin>:1:0: note: this is the location of the previous definition Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1361113416-8662-1-git-send-email-marcin.slusarz@gmail.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf report: Fix build with NO_NEWT=1Michael Ellerman2013-03-13
| | | | | | | | | | | | | | | | | | | | | | Commit ad0de09 "Enable the runtime switching of perf data file" broke the build with NO_NEWT=1: CC builtin-report.o builtin-report.c: In function '__cmd_report': builtin-report.c:479:15: error: 'K_SWITCH_INPUT_DATA' undeclared (first use in this function) builtin-report.c:479:15: note: each undeclared identifier is reported only once for each function it appears in builtin-report.c: In function 'cmd_report': builtin-report.c:823:13: error: 'K_SWITCH_INPUT_DATA' undeclared (first use in this function) make: *** [builtin-report.o] Error 1 Fix it by adding a dummy definition of K_SWITCH_INPUT_DATA. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Cc: Feng Tang <feng.tang@intel.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1361854923-1814-2-git-send-email-michael@ellerman.id.au Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf annotate: Fix build with NO_NEWT=1Michael Ellerman2013-03-13
| | | | | | | | | | | | | | | | | | | | | | | | Commit 18c9e5c "Make it to be able to skip unannotatable symbols" broke the build with NO_NEWT=1: CC builtin-annotate.o builtin-annotate.c: In function 'hists__find_annotations': builtin-annotate.c:161:4: error: duplicate case value builtin-annotate.c:154:4: error: previously used here make: *** [builtin-annotate.o] Error 1 This is because without NEWT support K_LEFT is #defined to -1 in utils/hist.h Fix it by shifting the K_LEFT/K_RIGHT #defines out of the likely range of error values. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Cc: Feng Tang <feng.tang@intel.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1361854923-1814-1-git-send-email-michael@ellerman.id.au Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* s390: Fix a header dependencies related build errorLi Zefan2013-03-11
| | | | | | | | | | | | | | | | | | | | | | | Commit 877c685607925238e302cd3aa38788dca6c1b226 ("perf: Remove include of cgroup.h from perf_event.h") caused this build failure if PERF_EVENTS is enabled: In file included from arch/s390/include/asm/perf_event.h:9:0, from include/linux/perf_event.h:24, from kernel/events/ring_buffer.c:12: arch/s390/include/asm/cpu_mf.h: In function 'qctri': arch/s390/include/asm/cpu_mf.h:61:12: error: 'EINVAL' undeclared (first use in this function) cpu_mf.h had an implicit errno.h dependency, which was added indirectly via cgroups.h but not anymore. Add it explicitly. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Li Zefan <lizefan@huawei.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Link: http://lkml.kernel.org/r/51385F79.7000106@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* tracing: update documentation of snapshot utilityHiraku Toyooka2013-03-08
| | | | | | | | | | | Now, "snapshot" file returns success on a reset of snapshot buffer even if the buffer wasn't allocated, instead of returning EINVAL. This patch updates snapshot desctiption according to the change. Link: http://lkml.kernel.org/r/51399409.4090207@hitachi.com Signed-off-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Do not return EINVAL in snapshot when not allocatedSteven Rostedt (Red Hat)2013-03-07
| | | | | | | | | | | | | | | | | | To use the tracing snapshot feature, writing a '1' into the snapshot file causes the snapshot buffer to be allocated if it has not already been allocated and dose a 'swap' with the main buffer, so that the snapshot now contains what was in the main buffer, and the main buffer now writes to what was the snapshot buffer. To free the snapshot buffer, a '0' is written into the snapshot file. To clear the snapshot buffer, any number but a '0' or '1' is written into the snapshot file. But if the file is not allocated it returns -EINVAL error code. This is rather pointless. It is better just to do nothing and return success. Acked-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* tracing: Add help of snapshot feature when snapshot is emptySteven Rostedt (Red Hat)2013-03-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When cat'ing the snapshot file, instead of showing an empty trace header like the trace file does, show how to use the snapshot feature. Also, this is a good place to show if the snapshot has been allocated or not. Users may want to "pre allocate" the snapshot to have a fast "swap" of the current buffer. Otherwise, a swap would be slow and might fail as it would need to allocate the snapshot buffer, and that might fail under tight memory constraints. Here's what it looked like before: # tracer: nop # # entries-in-buffer/entries-written: 0/0 #P:4 # # _-----=> irqs-off # / _----=> need-resched # | / _---=> hardirq/softirq # || / _--=> preempt-depth # ||| / delay # TASK-PID CPU# |||| TIMESTAMP FUNCTION # | | | |||| | | Here's what it looks like now: # tracer: nop # # # * Snapshot is freed * # # Snapshot commands: # echo 0 > snapshot : Clears and frees snapshot buffer # echo 1 > snapshot : Allocates snapshot buffer, if not already allocated. # Takes a snapshot of the main buffer. # echo 2 > snapshot : Clears snapshot buffer (but does not allocate) # (Doesn't have to be '2' works with any number that # is not a '0' or '1') Acked-by: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'tip/perf/urgent' of ↵Ingo Molnar2013-02-28
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull an ftrace Kconfig help text fix from Steve Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * ftrace: Update the kconfig for DYNAMIC_FTRACESteven Rostedt2013-02-27
|/ | | | | | | | | | | | | | | | | | | | | | | The prompt to enable DYNAMIC_FTRACE (the ability to nop and enable function tracing at run time) had a confusing statement: "enable/disable ftrace tracepoints dynamically" This was written before tracepoints were added to the kernel, but now that tracepoints have been added, this is very confusing and has confused people enough to give wrong information during presentations. Not only that, I looked at the help text, and it still references that dreaded daemon that use to wake up once a second to update the nop locations and brick NICs, that hasn't been around for over five years. Time to bring the text up to the current decade. Cc: stable@vger.kernel.org Reported-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge branch 'tip/perf/core' of ↵Ingo Molnar2013-02-20
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent Pull two fixes from Steven Rostedt. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * ftrace: Call ftrace cleanup module notifier after all other notifiersSteven Rostedt (Red Hat)2013-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit: c1bf08ac "ftrace: Be first to run code modification on modules" changed ftrace module notifier's priority to INT_MAX in order to process the ftrace nops before anything else could touch them (namely kprobes). This was the correct thing to do. Unfortunately, the ftrace module notifier also contains the ftrace clean up code. As opposed to the set up code, this code should be run *after* all the module notifiers have run in case a module is doing correct clean-up and unregisters its ftrace hooks. Basically, ftrace needs to do clean up on module removal, as it needs to know about code being removed so that it doesn't try to modify that code. But after it removes the module from its records, if a ftrace user tries to remove a probe, that removal will fail due as the record of that code segment no longer exists. Nothing really bad happens if the probe removal is called after ftrace did the clean up, but the ftrace removal function will return an error. Correct code (such as kprobes) will produce a WARN_ON() if it fails to remove the probe. As people get annoyed by frivolous warnings, it's best to do the ftrace clean up after everything else. By splitting the ftrace_module_notifier into two notifiers, one that does the module load setup that is run at high priority, and the other that is called for module clean up that is run at low priority, the problem is solved. Cc: stable@vger.kernel.org Reported-by: Frank Ch. Eigler <fche@redhat.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing/syscalls: Allow archs to ignore tracing compat syscallsSteven Rostedt2013-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tracing of ia32 compat system calls has been a bit of a pain as they use different system call numbers than the 64bit equivalents. I wrote a simple 'lls' program that lists files. I compiled it as a i686 ELF binary and ran it under a x86_64 box. This is the result: echo 0 > /debug/tracing/tracing_on echo 1 > /debug/tracing/events/syscalls/enable echo 1 > /debug/tracing/tracing_on ; ./lls ; echo 0 > /debug/tracing/tracing_on grep lls /debug/tracing/trace [.. skipping calls before TS_COMPAT is set ...] lls-1127 [005] d... 936.409188: sys_recvfrom(fd: 0, ubuf: 4d560fc4, size: 0, flags: 8048034, addr: 8, addr_len: f7700420) lls-1127 [005] d... 936.409190: sys_recvfrom -> 0x8a77000 lls-1127 [005] d... 936.409211: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) lls-1127 [005] d... 936.409215: sys_lgetxattr -> 0xf76ff000 lls-1127 [005] d... 936.409223: sys_dup2(oldfd: 4d55ae9b, newfd: 4) lls-1127 [005] d... 936.409228: sys_dup2 -> 0xfffffffffffffffe lls-1127 [005] d... 936.409236: sys_newfstat(fd: 4d55b085, statbuf: 80000) lls-1127 [005] d... 936.409242: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409243: sys_removexattr(pathname: 3, name: ffcd0060) lls-1127 [005] d... 936.409244: sys_removexattr -> 0x0 lls-1127 [005] d... 936.409245: sys_lgetxattr(pathname: 0, name: 19614, value: 1, size: 2) lls-1127 [005] d... 936.409248: sys_lgetxattr -> 0xf76e5000 lls-1127 [005] d... 936.409248: sys_newlstat(filename: 3, statbuf: 19614) lls-1127 [005] d... 936.409249: sys_newlstat -> 0x0 lls-1127 [005] d... 936.409262: sys_newfstat(fd: f76fb588, statbuf: 80000) lls-1127 [005] d... 936.409279: sys_newfstat -> 0x3 lls-1127 [005] d... 936.409279: sys_close(fd: 3) lls-1127 [005] d... 936.421550: sys_close -> 0x200 lls-1127 [005] d... 936.421558: sys_removexattr(pathname: 3, name: ffcd00d0) lls-1127 [005] d... 936.421560: sys_removexattr -> 0x0 lls-1127 [005] d... 936.421569: sys_lgetxattr(pathname: 4d564000, name: 1b1abc, value: 5, size: 802) lls-1127 [005] d... 936.421574: sys_lgetxattr -> 0x4d564000 lls-1127 [005] d... 936.421575: sys_capget(header: 4d70f000, dataptr: 1000) lls-1127 [005] d... 936.421580: sys_capget -> 0x0 lls-1127 [005] d... 936.421580: sys_lgetxattr(pathname: 4d710000, name: 3000, value: 3, size: 812) lls-1127 [005] d... 936.421589: sys_lgetxattr -> 0x4d710000 lls-1127 [005] d... 936.426130: sys_lgetxattr(pathname: 4d713000, name: 2abc, value: 3, size: 32) lls-1127 [005] d... 936.426141: sys_lgetxattr -> 0x4d713000 lls-1127 [005] d... 936.426145: sys_newlstat(filename: 3, statbuf: f76ff3f0) lls-1127 [005] d... 936.426146: sys_newlstat -> 0x0 lls-1127 [005] d... 936.431748: sys_lgetxattr(pathname: 0, name: 1000, value: 3, size: 22) Obviously I'm not calling newfstat with a fd of 4d55b085. The calls are obviously incorrect, and confusing. Other efforts have been made to fix this: https://lkml.org/lkml/2012/3/26/367 But the real solution is to rewrite the syscall internals and come up with a fixed solution. One that doesn't require all the kluge that the current solution has. Thus for now, instead of outputting incorrect data, simply ignore them. With this patch the changes now have: #> grep lls /debug/tracing/trace #> Compat system calls simply are not traced. If users need compat syscalls, then they should just use the raw syscall tracepoints. For an architecture to make their compat syscalls ignored, it must define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS (done in asm/ftrace.h) and also define an arch_trace_is_compat_syscall() function that will return true if the current task should ignore tracing the syscall. I want to stress that this change does not affect actual syscalls in any way, shape or form. It is only used within the tracing system and doesn't interfere with the syscall logic at all. The changes are consolidated nicely into trace_syscalls.c and asm/ftrace.h. I had to make one small modification to asm/thread_info.h and that was to remove the include of asm/ftrace.h. As asm/ftrace.h required the current_thread_info() it was causing include hell. That include was added back in 2008 when the function graph tracer was added: commit caf4b323 "tracing, x86: add low level support for ftrace return tracing" It does not need to be included there. Link: http://lkml.kernel.org/r/1360703939.21867.99.camel@gandalf.local.home Acked-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | perf/x86: Add Intel IvyBridge event scheduling constraintsStephane Eranian2013-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Intel IvyBridge processor has different constraints compared to SandyBridge. Therefore it needs its own contraint table. This patch adds the constraint table. Without this patch, the events listed in the patch may not be scheduled correctly and bogus counts may be collected. Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: ak@linux.intel.com Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: namhyung.kim@lge.com Link: http://lkml.kernel.org/r/1361355312-3323-1-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'for-3.9-async' of ↵Linus Torvalds2013-02-20
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull async changes from Tejun Heo: "These are followups for the earlier deadlock issue involving async ending up waiting for itself through block requesting module[1]. The following changes are made by these commits. - Instead of requesting default elevator on each request_queue init, block now requests it once early during boot. - Kmod triggers warning if invoked from an async worker. - Async synchronization implementation has been reimplemented. It's a lot simpler now." * 'for-3.9-async' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: async: initialise list heads to fix crash async: replace list of active domains with global list of pending items async: keep pending tasks on async_domain and remove async_pending async: use ULLONG_MAX for infinity cookie value async: bring sanity to the use of words domain and running async, kmod: warn on synchronous request_module() from async workers block: don't request module during elevator init init, block: try to load default elevator module early during boot
| * | async: initialise list heads to fix crashJames Hogan2013-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 9fdb04cdc55 ("async: replace list of active domains with global list of pending items") added a struct list_head global_list in struct async_entry, which isn't initialised. This means that if !domain->registered at __async_schedule(), then list_del_init() will be called on the list head in async_run_entry_fn with both pointers NULL, causing a crash. This is fixed by initialising both the global_list and domain_list list_heads after kzalloc'ing the entry. This was noticed due to dapm_power_widgets() which uses ASYNC_DOMAIN_EXCLUSIVE, which initialises the domain->registered to 0. Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: James Hogan <james.hogan@imgtec.com> Reported-by: Stephen Warren <swarren@wwwdotorg.org>
| * | async: replace list of active domains with global list of pending itemsTejun Heo2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Global synchronization - async_synchronize_full() - is currently implemented by keeping a list of all active registered domains and syncing them one by one until no domain is active. While this isn't necessarily a complex scheme, it can easily be simplified by keeping global list of the pending items of all registered active domains instead of list of domains and simply using the globl pending list the same way as domain syncing. This patch replaces async_domains with async_global_pending and update lowest_in_progress() to use the global pending list if @domain is %NULL. async_synchronize_full_domain(NULL) is now allowed and equivalent to async_synchronize_full(). As no one is calling with NULL domain, this doesn't affect any existing users. async_register_mutex is no longer necessary and dropped. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <djbw@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | async: keep pending tasks on async_domain and remove async_pendingTejun Heo2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Async kept single global pending list and per-domain running lists. When an async item is queued, it's put on the global pending list. The item is moved to the per-domain running list when its execution starts. At this point, this design complicates execution and synchronization without bringing any benefit. The list only matters for synchronization which doesn't care whether a given async item is pending or executing. Also, global synchronization is done by iterating through all active registered async_domains, so the global async_pending list doesn't help anything either. Rename async_domain->running to async_domain->pending and put async items directly there and remove when execution completes. This simplifies lowest_in_progress() a lot - the first item on the pending list is the one with the lowest cookie, and async_run_entry_fn() doesn't have to mess with moving the item from pending to running. After the change, whether a domain is empty or not can be trivially determined by looking at async_domain->pending. Remove async_domain->count and use list_empty() on pending instead. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <djbw@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | async: use ULLONG_MAX for infinity cookie valueTejun Heo2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, next_cookie is used as the infinity value. In most cases, this should work fine but it theoretically could bring subtle behavior difference between async_synchronize_full() and async_synchronize_full_domain(). async_synchronize_full() keeps waiting until there's no registered async_entry left regardless of what next_cookie was when the function was called. It guarantees that the queue is completely drained at least once before returning. However, async_synchronize_full_domain() doesn't. It synchronizes upto next_cookie and if further async jobs are queued after the next_cookie value to synchronize is decided, they won't be waited for. For unrelated async jobs, the behavior difference doesn't matter; however, if async jobs which are related (nested or otherwise) to the executing ones are queued while sychronization is in progress, the resulting behavior difference could be problematic. This can be easily fixed by using ULLONG_MAX as the infinity value instead. Define ASYNC_COOKIE_MAX as ULLONG_MAX and use it as the infinity value for synchronization. This makes async_synchronize_full_domain() fully drain the domain at least once before returning, making its behavior match async_synchronize_full(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <djbw@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | async: bring sanity to the use of words domain and runningTejun Heo2013-01-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the beginning, running lists were literal struct list_heads. Later on, struct async_domain was added. For some reason, while the conversion substituted list_heads with async_domains, the variable names weren't fully converted. In more places, "running" was used for struct async_domain while other places adopted new "domain" name. The situation is made much worse by having async_domain's running list named "domain" and async_entry's field pointing to async_domain named "running". So, we end up with mix of "running" and "domain" for variable names for async_domain, with the field names of async_domain and async_entry swapped between "running" and "domain". It feels almost intentionally made to be as confusing as possible. Bring some sanity by * Renaming all async_domain variables "domain". * s/async_running/async_dfl_domain/ * s/async_domain->domain/async_domain->running/ * s/async_entry->running/async_entry->domain/ Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Dan Williams <djbw@fb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org>
| * | Merge branch 'master' into for-3.9-asyncTejun Heo2013-01-23
| |\ \ | | | | | | | | | | | | | | | | | | | | | | | | To receive f56c3196f251012de9b3ebaff55732a9074fdaae ("async: fix __lowest_in_progress()"). Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | async, kmod: warn on synchronous request_module() from async workersTejun Heo2013-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Synchronous requet_module() from an async worker can lead to deadlock because module init path may invoke async_synchronize_full(). The async worker waits for request_module() to complete and the module loading waits for the async task to finish. This bug happened in the block layer because of default elevator auto-loading. Block layer has been updated not to do default elevator auto-loading and it has been decided to disallow synchronous request_module() from async workers. Trigger WARN_ON_ONCE() on synchronous request_module() from async workers. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Alex Riesen <raa.lkml@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com>
| * | | block: don't request module during elevator initTejun Heo2013-01-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Block layer allows selecting an elevator which is built as a module to be selected as system default via kernel param "elevator=". This is achieved by automatically invoking request_module() whenever a new block device is initialized and the elevator is not available. This led to an interesting deadlock problem involving async and module init. Block device probing running off an async job invokes request_module(). While the module is being loaded, it performs async_synchronize_full() which ends up waiting for the async job which is already waiting for request_module() to finish, leading to deadlock. Invoking request_module() from deep in block device init path is already nasty in itself. It seems best to avoid these situations from the beginning by moving on-demand module loading out of block init path. The previous patch made sure that the default elevator module is loaded early during boot if available. This patch removes on-demand loading of the default elevator from elevator init path. As the module would have been loaded during boot, userland-visible behavior difference should be minimal. For more details, please refer to the following thread. http://thread.gmane.org/gmane.linux.kernel/1420814 v2: The bool parameter was named @request_module which conflicted with request_module(). This built okay w/ CONFIG_MODULES because request_module() was defined as a macro. W/o CONFIG_MODULES, it causes build breakage. Rename the parameter to @try_loading. Reported by Fengguang. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alex Riesen <raa.lkml@gmail.com> Cc: Fengguang Wu <fengguang.wu@intel.com>
| * | | init, block: try to load default elevator module early during bootTejun Heo2013-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds default module loading and uses it to load the default block elevator. During boot, it's called right after initramfs or initrd is made available and right before control is passed to userland. This ensures that as long as the modules are available in the usual places in initramfs, initrd or the root filesystem, the default modules are loaded as soon as possible. This will replace the on-demand elevator module loading from elevator init path. v2: Fixed build breakage when !CONFIG_BLOCK. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alex Riesen <raa.lkml@gmail.com> Cc: Fengguang We <fengguang.wu@intel.com>
* | | | Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2013-02-20
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull workqueue changes from Tejun Heo: "A lot of reorganization is going on mostly to prepare for worker pools with custom attributes so that workqueue can replace custom pool implementations in places including writeback and btrfs and make CPU assignment in crypto more flexible. workqueue evolved from purely per-cpu design and implementation, so there are a lot of assumptions regarding being bound to CPUs and even unbound workqueues are implemented as an extension of the model - workqueues running on the special unbound CPU. Bulk of changes this round are about promoting worker_pools as the top level abstraction replacing global_cwq (global cpu workqueue). At this point, I'm fairly confident about getting custom worker pools working pretty soon and ready for the next merge window. Lai's patches are replacing the convoluted mb() dancing workqueue has been doing with much simpler mechanism which only depends on assignment atomicity of long. For details, please read the commit message of 0b3dae68ac ("workqueue: simplify is-work-item-queued-here test"). While the change ends up adding one pointer to struct delayed_work, the inflation in percentage is less than five percent and it decouples delayed_work logic a lot more cleaner from usual work handling, removes the unusual memory barrier dancing, and allows for further simplification, so I think the trade-off is acceptable. There will be two more workqueue related pull requests and there are some shared commits among them. I'll write further pull requests assuming this pull request is pulled first." * 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (37 commits) workqueue: un-GPL function delayed_work_timer_fn() workqueue: rename cpu_workqueue to pool_workqueue workqueue: reimplement is_chained_work() using current_wq_worker() workqueue: fix is_chained_work() regression workqueue: pick cwq instead of pool in __queue_work() workqueue: make get_work_pool_id() cheaper workqueue: move nr_running into worker_pool workqueue: cosmetic update in try_to_grab_pending() workqueue: simplify is-work-item-queued-here test workqueue: make work->data point to pool after try_to_grab_pending() workqueue: add delayed_work->wq to simplify reentrancy handling workqueue: make work_busy() test WORK_STRUCT_PENDING first workqueue: replace WORK_CPU_NONE/LAST with WORK_CPU_END workqueue: post global_cwq removal cleanups workqueue: rename nr_running variables workqueue: remove global_cwq workqueue: remove worker_pool->gcwq workqueue: replace for_each_worker_pool() with for_each_std_worker_pool() workqueue: make freezing/thawing per-pool workqueue: make hotplug processing per-pool ...
| * | | | workqueue: un-GPL function delayed_work_timer_fn()Konstantin Khlebnikov2013-02-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d8e794dfd51c368ed3f686b7f4172830b60ae47b ("workqueue: set delayed_work->timer function on initialization") exports function delayed_work_timer_fn() only for GPL modules. This makes delayed-works unusable for non-GPL modules, because initialization macro now requires GPL symbol. For example schedule_delayed_work() available for non-GPL. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org # 3.7
| * | | | workqueue: rename cpu_workqueue to pool_workqueueTejun Heo2013-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | workqueue has moved away from global_cwqs to worker_pools and with the scheduled custom worker pools, wforkqueues will be associated with pools which don't have anything to do with CPUs. The workqueue code went through significant amount of changes recently and mass renaming isn't likely to hurt much additionally. Let's replace 'cpu' with 'pool' so that it reflects the current design. * s/struct cpu_workqueue_struct/struct pool_workqueue/ * s/cpu_wq/pool_wq/ * s/cwq/pwq/ This patch is purely cosmetic. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | workqueue: reimplement is_chained_work() using current_wq_worker()Tejun Heo2013-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | is_chained_work() was added before current_wq_worker() and implemented its own ham-fisted way of finding out whether %current is a workqueue worker - it iterates through all possible workers. Drop the custom implementation and reimplement using current_wq_worker(). Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | workqueue: fix is_chained_work() regressionTejun Heo2013-02-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | c9e7cf273f ("workqueue: move busy_hash from global_cwq to worker_pool") incorrectly converted is_chained_work() to use get_gcwq() inside for_each_gcwq_cpu() while removing get_gcwq(). As cwq might not exist for all possible workqueue CPUs, @cwq can be NULL and the following cwq deferences can lead to oops. Fix it by using for_each_cwq_cpu() instead, which is the better one to use anyway as we only need to check pools that the wq is associated with. Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | workqueue: pick cwq instead of pool in __queue_work()Lai Jiangshan2013-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, __queue_work() chooses the pool to queue a work item to and then determines cwq from the target wq and the chosen pool. This is a bit backwards in that we can determine cwq first and simply use cwq->pool. This way, we can skip get_std_worker_pool() in queueing path which will be a hurdle when implementing custom worker pools. Update __queue_work() such that it chooses the target cwq and then use cwq->pool instead of the other way around. While at it, add missing {} in an if statement. This patch doesn't introduce any functional changes. tj: The original patch had two get_cwq() calls - the first to determine the pool by doing get_cwq(cpu, wq)->pool and the second to determine the matching cwq from get_cwq(pool->cpu, wq). Updated the function such that it chooses cwq instead of pool and removed the second call. Rewrote the description. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | workqueue: make get_work_pool_id() cheaperLai Jiangshan2013-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | get_work_pool_id() currently first obtains pool using get_work_pool() and then return pool->id. For an off-queue work item, this involves obtaining pool ID from worker->data, performing idr_find() to find the matching pool and then returning its pool->id which of course is the same as the one which went into idr_find(). Just open code WORK_STRUCT_CWQ case and directly return pool ID from work->data. tj: The original patch dropped on-queue work item handling and renamed the function to offq_work_pool_id(). There isn't much benefit in doing so. Handling it only requires a single if() and we need at least BUG_ON(), which is also a branch, even if we drop on-queue handling. Open code WORK_STRUCT_CWQ case and keep the function in line with get_work_pool(). Rewrote the description. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | | workqueue: move nr_running into worker_poolTejun Heo2013-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As nr_running is likely to be accessed from other CPUs during try_to_wake_up(), it was kept outside worker_pool; however, while less frequent, other fields in worker_pool are accessed from other CPUs for, e.g., non-reentrancy check. Also, with recent pool related changes, accessing nr_running matching the worker_pool isn't as simple as it used to be. Move nr_running inside worker_pool. Keep it aligned to cacheline and define CPU pools using DEFINE_PER_CPU_SHARED_ALIGNED(). This should give at least the same cacheline behavior. get_pool_nr_running() is replaced with direct pool->nr_running accesses. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Joonsoo Kim <js1304@gmail.com>
| * | | | workqueue: cosmetic update in try_to_grab_pending()Tejun Heo2013-02-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the recent is-work-queued-here test simplification, the nested if() in try_to_grab_pending() can be collapsed. Collapse it. This patch is purely cosmetic. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
| * | | | workqueue: simplify is-work-item-queued-here testLai Jiangshan2013-02-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, determining whether a work item is queued on a locked pool involves somewhat convoluted memory barrier dancing. It goes like the following. * When a work item is queued on a pool, work->data is updated before work->entry is linked to the pending list with a wmb() inbetween. * When trying to determine whether a work item is currently queued on a pool pointed to by work->data, it locks the pool and looks at work->entry. If work->entry is linked, we then do rmb() and then check whether work->data points to the current pool. This works because, work->data can only point to a pool if it currently is or were on the pool and, * If it currently is on the pool, the tests would obviously succeed. * It it left the pool, its work->entry was cleared under pool->lock, so if we're seeing non-empty work->entry, it has to be from the work item being linked on another pool. Because work->data is updated before work->entry is linked with wmb() inbetween, work->data update from another pool is guaranteed to be visible if we do rmb() after seeing non-empty work->entry. So, we either see empty work->entry or we see updated work->data pointin to another pool. While this works, it's convoluted, to put it mildly. With recent updates, it's now guaranteed that work->data points to cwq only while the work item is queued and that updating work->data to point to cwq or back to pool is done under pool->lock, so we can simply test whether work->data points to cwq which is associated with the currently locked pool instead of the convoluted memory barrier dancing. This patch replaces the memory barrier based "are you still here, really?" test with much simpler "does work->data points to me?" test - if work->data points to a cwq which is associated with the currently locked pool, the work item is guaranteed to be queued on the pool as work->data can start and stop pointing to such cwq only under pool->lock and the start and stop coincide with queue and dequeue. tj: Rewrote the comments and description. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-02 06:34:38 -0500