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* perf bench futex: Add lock_pi stresserDavidlohr Bueso2015-07-206-0/+248
| | | | | | | | | | | | | | | | | | | | Allows a way of measuring low level kernel implementation of FUTEX_LOCK_PI and FUTEX_UNLOCK_PI. The program comes in two flavors: (i) single futex (default), all threads contend on the same uaddr. For the sake of the benchmark, we call into kernel space even when the lock is uncontended. The kernel will set it to TID, any waters that come in and contend for the pi futex will be handled respectively by the kernel. (ii) -M option for multiple futexes, each thread deals with its own futex. This is a trivial scenario and only measures kernel handling of 0->TID transition. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Mel Gorman <mgorman@suse.de> Link: http://lkml.kernel.org/r/1436259353.12255.78.camel@stgolabs.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf tools: Fix makefile generation under dashSergei Trofimovich2015-07-201-1/+1
| | | | | | | | | | | | | Under dash 'echo -n' yields '-n' to stdout. Use printf "" instead. Signed-off-by: Sergei Trofimovich <siarheit@google.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1437298205-29305-1-git-send-email-siarheit@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf buildid: Use SBUILD_ID_SIZE macroMasami Hiramatsu2015-07-204-9/+10
| | | | | | | | | | | | | | | | Introduce SBUILD_ID_SIZE macro and use it instead of using BUILD_ID_SIZE * 2 + 1. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20150715091428.8915.75265.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe: Move ftrace probe-event operations to probe-file.cMasami Hiramatsu2015-07-205-292/+353
| | | | | | | | | | | | | | | | Move ftrace probe-event operations to probe-file.c from probe-event.c. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20150715091407.8915.14316.stgit@localhost.localdomain [ Fixed up strlist__new() calls wrt 4a77e2183fc0 ("perf strlist: Make dupstr be the...") ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf probe: Simplify __add_probe_trace_events codeMasami Hiramatsu2015-07-201-27/+43
| | | | | | | | | | | | | | | | Simplify the __add_probe_trace_events() code by taking out the probe_trace_event__set_name() and updating show_perf_probe_event() Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20150715091400.8915.85501.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf record: Allow filtering perf's pid via --exclude-perfWang Nan2015-07-204-14/+84
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch allows 'perf record' to exclude events issued by perf itself by '--exclude-perf' option. Before this patch, when doing something like: # perf record -a -e syscalls:sys_enter_write <cmd> One could easily get result like this: # /tmp/perf report --stdio ... # Overhead Command Shared Object Symbol # ........ ....... .................. .................... # 99.99% perf libpthread-2.18.so [.] __write_nocancel 0.01% ls libc-2.18.so [.] write 0.01% sshd libc-2.18.so [.] write ... Where most events are generated by perf itself. A shell trick can be done to filter perf itself out: # cat << EOF > ./tmp > #!/bin/sh > exec perf record -e ... --filter="common_pid != \$\$" -a sleep 10 > EOF # chmod a+x ./tmp # ./tmp However, doing so is user unfriendly. This patch extracts evsel iteration framework introduced by patch 'perf record: Apply filter to all events in a glob matching' into foreach_evsel_in_last_glob(), and makes exclude_perf() function append new filter expression to each evsel selected by a '-e' selector. To avoid losing filters if user pass '--filter' after '--exclude-perf', this patch uses perf_evsel__append_filter() in both case, instead of perf_evsel__set_filter() which removes old filter. As a side effect, now it is possible to use multiple '--filter' option for one selector. They are combinded with '&&'. Signed-off-by: Wang Nan <wangnan0@huawei.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1436513770-8896-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf record: Apply filter to all events in a glob matchingWang Nan2015-07-203-9/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is an old problem in perf's filter applying which first posted at Sep. 2014 at https://lkml.org/lkml/2014/9/9/944 that, if passing multiple events in a glob matching expression in cmdline then add '--filter' after them, the filter will be applied on only the last one. For example: # dd if=/dev/zero of=/dev/null & [1] 464 # perf record -a -e 'syscalls:sys_*_read' --filter 'common_pid != 464' sleep 0.1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.239 MB perf.data (2094 samples) ] # perf report --stdio | tee ... # Samples: 2K of event 'syscalls:sys_enter_read' # Event count (approx.): 2092 ... # Samples: 2 of event 'syscalls:sys_exit_read' # Event count (approx.): 2 ... In this example, filter only applied on 'syscalls:sys_exit_read', and there's no way to set filter for ''syscalls:sys_enter_read'. This patch adds a 'cmdline_group_boundary' for 'struct evsel', and apply filter on all events between two boundary marks. After applying this patch: # perf record -a -e 'syscalls:sys_*_read' --filter 'common_pid != 464' sleep 0.1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.031 MB perf.data (3 samples) ] # perf report --stdio | tee ... # Samples: 1 of event 'syscalls:sys_enter_read' # Event count (approx.): 1 ... # Samples: 2 of event 'syscalls:sys_exit_read' # Event count (approx.): 2 ... Signed-off-by: Wang Nan <wangnan0@huawei.com> Reported-by: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1436513770-8896-1-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf trace: Support 'strace' syscall event groupsArnaldo Carvalho de Melo2015-07-205-1/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | I.e.: $ cat ~/share/perf-core/strace/groups/file access chmod creat execve faccessat getcwd lstat mkdir open openat quotactl readlink rename rmdir stat statfs symlink unlink $ Then, on a quiet desktop, try running this and then moving your mouse to see the deluge of mouse related activity: # perf probe 'vfs_getname=getname_flags:72 pathname=filename:string' Added new event: probe:vfs_getname (on getname_flags:72 with pathname=filename:string) You can now use it in all perf tools, such as: perf record -e probe:vfs_getname -aR sleep 1 # # trace --ev probe:vfs_getname --filter-pids 2232 -e file 0.042 (0.042 ms): mousetweaks/2235 open(filename: 0x14e3910, mode: 438 ) ... 0.042 ( ): probe:vfs_getname:(ffffffff812230bc) pathname="/home/acme/.icons/Adwaita/cursors/xterm") 0.100 (0.100 ms): mousetweaks/2235 ... [continued]: open()) = -1 ENOENT No such file or directory 0.142 (0.018 ms): mousetweaks/2235 open(filename: 0x14c3c10, mode: 438 ) ... 0.142 ( ): probe:vfs_getname:(ffffffff812230bc) pathname="/home/acme/.icons/Adwaita/index.theme") 0.192 (0.069 ms): mousetweaks/2235 ... [continued]: open()) = -1 ENOENT No such file or directory 0.230 (0.017 ms): mousetweaks/2235 open(filename: 0x14c3c10, mode: 438 ) ... 0.230 ( ): probe:vfs_getname:(ffffffff812230bc) pathname="/usr/share/icons/Adwaita/cursors/xterm") 0.253 (0.041 ms): mousetweaks/2235 ... [continued]: open()) = 14 0.459 (0.008 ms): mousetweaks/2235 open(filename: 0x14e3910, mode: 438 ) ... 0.459 ( ): probe:vfs_getname:(ffffffff812230bc) pathname="/home/acme/.icons/Adwaita/cursors/left_side") 0.468 (0.017 ms): mousetweaks/2235 ... [continued]: open()) = -1 ENOENT No such file or directory Need to combine that raw_syscalls:sys_enter(open) + probe:vfs_getname + raw_syscalls:sys_exit(open) sequence... Now, if you're bored, please write some more syscall groups, like the ones in 'strace' and send it our way :-) Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Milian Wolff <mail@milianw.de> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-a42xklu59lcbxp7bbnic74a8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf strlist: Make parse_list() privateArnaldo Carvalho de Melo2015-07-202-3/+1
| | | | | | | | | | | | | | It is not used anywhere, expose it when/if needed. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-f6in51stj17avhk4rv11gjgg@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf strlist: Allow substitutions from file contents in a given directoryArnaldo Carvalho de Melo2015-07-202-8/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So, if we have an strlist equal to: "file,close" And we call it as: struct strlist_config *config = { .dirname = "~/strace/groups", }; struct strlist *slist = strlist__new("file, close", &config); And we have: $ cat ~/strace/groups/file access open openat statfs Then the resulting strlist will have these contents: [ "access", "open", "openat", "statfs", "close" ] This will be used to implement strace syscall groups in 'perf trace', but can be used in some other tool, thus being implemented in 'strlist'. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-wi6l6qtomqlywwr6005jvs05@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf strlist: Make dupstr be the default and part of an extensible config parmArnaldo Carvalho de Melo2015-07-2010-16/+22
| | | | | | | | | | | | | | | | So that we can pass more info to strlist__new() without having to change its function signature, just adding entries to the strlist_config struct with sensible defaults for when those fields are not specified. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-5uaaler4931i0s9sedxjquhq@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf strlist: load() should return a negative errnoArnaldo Carvalho de Melo2015-07-161-1/+1
| | | | | | | | | | | | | | To match what its users return. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-jntpe2lwg1fxn1bku7uccan0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* perf record: Document setting '-e pmu/period=N/' in man pageKan Liang2015-07-141-0/+8
| | | | | | | | | | | | | The 'period' param is not defined in /sys/bus/event_sources/devices/<pmu>/format/*, but can be used, document it. Signed-off-by: Kan Liang <kan.liang@intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1436345097-11113-3-git-send-email-kan.liang@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* Merge tag 'perf-core-for-mingo' of ↵Ingo Molnar2015-07-0611-81/+224
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible changes: - Take tracefs into account when reporting errors about accessing tracepoint information in tools like 'perf trace' (Arnaldo Carvalho de Melo) - Let user have timestamps with per-thread recording in 'perf record' (Adrian Hunter) Infrastructure changes: - Introduce series of functions to build event filters so that we can set them in just one ioctl call, useful to set up common_pid, raw_syscalls:sys_{enter,exit}'s "id" filters to use with 'perf trace' (Arnaldo Carvalho de Melo) - Delete an unnecessary check before calling strfilter__delete() (Markus Elfring) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * tools lib api debugfs: Check for tracefs when reporting errorsArnaldo Carvalho de Melo2015-07-061-2/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we have two mountpoints, one for debugfs and another, for tracefs, we end up needing to check permissions for both, so, on a system with default config we were always asking the user to check the permission of the debugfs mountpoint, even when it was already sufficient. Fix it. E.g.: $ trace -e nanosleep usleep 1 Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit) Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug' $ sudo mount -o remount,mode=755 /sys/kernel/debug $ trace -e nanosleep usleep 1 Error: No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit) Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing' $ sudo mount -o remount,mode=755 /sys/kernel/debug/tracing $ trace -e nanosleep usleep 1 0.326 ( 0.061 ms): usleep/11961 nanosleep(rqtp: 0x7ffef1081c50) = 0 $ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/n/tip-0viljeuhc7q84ic8kobsna43@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf record: Let user have timestamps with per-thread recordingAdrian Hunter2015-07-063-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | If the option -T is used with option --per-thread, then time is still not sampled. Fix that by using OPT_BOOLEAN_SET to distinguish when the user used the -T option as opposed to the default case when timestamps are enabled but only for per-cpu recording. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Link: http://lkml.kernel.org/r/1436183461-1918-1-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf probe: Delete an unnecessary check before the function call ↵Markus Elfring2015-07-061-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "strfilter__delete" The strfilter__delete() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: kernel-janitors@vger.kernel.org Link: http://lkml.kernel.org/r/5597751A.5000506@users.sourceforge.net Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf trace: Use event filters for the event qualifier listArnaldo Carvalho de Melo2015-07-061-20/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We use raw_syscalls:sys_{enter,exit} events to show the syscalls, but were using a rather lazy/inneficient way to implement our 'strace -e' equivalent: filter out after reading the events in the ring buffer. Deflect more work to the kernel by appending a filter expression for that, that, together with the pid list, that is always present, if only to filter the tracer itself, reduces pressure on the ring buffer and otherwise use infrastructure already in place in the kernel to do early filtering. If we use it with -v we can see the filter passed to the kernel, for instance, for this contrieved case: # trace -v -e \!open,close,write,poll,recvfrom,select,recvmsg,writev,sendmsg,read,futex,epoll_wait,ioctl,eventfd --filter-pids 2189,2566,1398,2692,4475,4532 <SNIP> (common_pid != 2514 && common_pid != 1398 && common_pid != 2189 && common_pid != 2566 && common_pid != 2692 && common_pid != 4475 && common_pid != 4532) && (id != 3 && id != 232 && id != 284 && id != 202 && id != 16 && id != 2 && id != 7 && id != 0 && id != 45 && id != 47 && id != 23 && id != 46 && id != 1 && id != 20) 0.011 (0.011 ms): caribou/2295 eventfd2(flags: CLOEXEC|NONBLOCK) = 18 16.946 (0.019 ms): caribou/2295 eventfd2(flags: CLOEXEC|NONBLOCK) = 18 38.598 (0.167 ms): chronyd/794 socket(family: INET, type: DGRAM ) = 4 38.603 (0.002 ms): chronyd/794 fcntl(fd: 4<socket:[239307]>, cmd: GETFD) = 0 38.605 (0.001 ms): chronyd/794 fcntl(fd: 4<socket:[239307]>, cmd: SETFD, arg: 1) = 0 ^C # Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-ti2tg18atproqpguc2moinp6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf evsel: Introduce append_filter() methodArnaldo Carvalho de Melo2015-07-062-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To allow building filters in evsel->filter, that will eventually be applied via perf_evsel__apply_filter(). Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-sjfoes3pycx7nlpmgedca13v@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf evlist: Make perf_evlist__set_filter use perf_evsel__set_filterArnaldo Carvalho de Melo2015-07-062-7/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of calling perf_evsel__apply_filter straight away, so that we can, in the next patches, expand the filter with more conditions before actually calling the ioctl to pass the end result filter to the kernel. Now we need to call perf_evlist__apply_filters() after the filter is completely setup, i.e. do the ioctl calls. The perf_evlist__apply_filters() method was already in place, because that is the model for the other tools that receives filters in the command line: go on setting then in the evsel->filter and only at the end, after parsing the whole command line, apply them. We get, as a bonus, a more expressive message that states which event, if any, failed to have the filter applied to, with an error message stating what happened. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-f429pgz75ryz7tpe6v74etre@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf evsel: Introduce set_filter methodArnaldo Carvalho de Melo2015-07-063-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replaces existing filter string with the one provided. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-jst49z83li0yx3g18o54u51a@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf evsel: Rename set_filter to apply_filterArnaldo Carvalho de Melo2015-07-063-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need to be able to go on constructing a complex filter in multiple stages, since we can only set one filter per event. For instance, we need to be able, in 'perf trace' to filter by the 'common_pid' field all the time, if only for the tracer itself, to avoid a feedback loop, and, in addition, we may want to filter the raw_syscalls:sys_{enter,exit} events by its 'id' filter, when using 'perf trace -e open,close' or 'perf trace -e !open,close', i.e. when we are interested in just a subset of syscalls or when we are not interested in it. So we will have: perf_evsel__set_filter(evsel, char *filter) Replaces whatever is in evsel->filter. perf_evsel__append_filter(evsel, const char *op, char *filter) Appends, using op ("&&" or "||") with what is in evsel->filter. perf_evsel__apply_filter(evsel, filter): That actually applies a filter, be it the one being constructed in evsel->filter, or any other, for tools with more specific ways to build the filter, issuing the appropriate ioctl for all the evsel fds. The same changes will be made to the evlist__{set,apply} variants to keep everything consistent. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-2s5z9xtpnc2lwio3cv5x0jek@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf trace: Store the syscall ids for the event qualifiers in a tableArnaldo Carvalho de Melo2015-07-061-7/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That we will use to set a filter on raw_syscalls:sys_{enter,exit} events. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-2acxrcxyu7tlolrfilpty38y@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf trace: Remember what are the syscalls tracepoint evselsArnaldo Carvalho de Melo2015-07-061-39/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We will need to set filters on then. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-u8hpgjpf3w8o1prnnjnwegwf@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf tools: Asprintf like functions to format integer filter expressionArnaldo Carvalho de Melo2015-07-062-0/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | char *asprintf_expr_in_ints(const char *var, size_t nints, int *ints); char *asprintf_expr_not_in_ints(const char *var, size_t nints, int *ints); Example of output formatted with those functions: # ./tp_filter 6 12 2015 asprintf_expr_in_ints: id == 6 || id == 12 || id == 2015 asprintf_expr_not_in_ints: id != 6 && id != 12 && id != 2015 # It'll be used with, for instance, perf_evsel__set_filter_in_ints(), that will be used in turn to ask the kernel to filter out all raw_syscalls:* except for the ones specified by the user via: $ perf trace -e some,list,of,syscalls Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-jt07vfp6bd8y50c05j1t7hrn@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | perf/x86: Fix copy_from_user_nmi() return if range is not okYann Droneaud2015-07-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0a196848ca36 ("perf: Fix arch_perf_out_copy_user default"), changes copy_from_user_nmi() to return the number of remaining bytes so that it behave like copy_from_user(). Unfortunately, when the range is outside of the process memory, the return value is still the number of byte copied, eg. 0, instead of the remaining bytes. As all users of copy_from_user_nmi() were modified as part of commit 0a196848ca36, the function should be fixed to return the total number of bytes if range is not correct. Signed-off-by: Yann Droneaud <ydroneaud@opteya.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1435001923-30986-1-git-send-email-ydroneaud@opteya.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | perf: Fix AUX buffer refcountingPeter Zijlstra2015-07-063-10/+35
|/ | | | | | | | | | | | | | | | | | | Its currently possible to drop the last refcount to the aux buffer from NMI context, which results in the expected fireworks. The refcounting needs a bigger overhaul, but to cure the immediate problem, delay the freeing by using an irq_work. Reviewed-and-tested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20150618103249.GK19282@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'perf/rbtree_copy' of ↵Ingo Molnar2015-07-069-32/+959
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull rbtree build fix from Arnaldo Carvalho de Melo. Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * tools: Copy rbtree_augmented.h from the kernelArnaldo Carvalho de Melo2015-07-053-3/+246
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To complete the transitioning to not to share the same files with the kernel, also moving it from tools/perf/include/linux/ to tools/include/linux to make the whoke rbtree kit to other tools/ living codebases. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-5bxyehixafckqm6ez25alnfo@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * tools: Move rbtree.h from tools/perf/Arnaldo Carvalho de Melo2015-07-052-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The previous step, copying the contents minus the rcupdate.h parts, was done as a minimal fix, now do the move from tools/perf/. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-52fllxtsgmtke66pmv98mcma@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * tools: Copy lib/rbtree.c to tools/lib/Arnaldo Carvalho de Melo2015-07-054-12/+550
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So that we can remove kernel specific stuff we've been stubbing out via a tools/include/linux/export.h that gets removed in this patch and to avoid breakages in the future like the one fixed recently where rcupdate.h started being used in rbtree.h. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-rxuzfsozpb8hv1emwpx06rm6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * perf tools: Copy rbtree.h from the kernelArnaldo Carvalho de Melo2015-07-052-3/+90
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We were using the include/linux/rbtree.h directly from the kernel, which broke the build as soon as it started using rcupdate.h, to avoid dragging the rcu header files into tools/, for which there is no use so far, grab a copy of rbtree.h. This is the minimal fix, later patches will copy as well lib/rbtree.c and move rbtree.h into tools/include/, etc. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-dfmuj0j63w4by7vhlh4hhn74@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * tools: Adopt {READ,WRITE_ONCE} from the kernelArnaldo Carvalho de Melo2015-07-051-0/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need it to build rbtree.c after this cset: commit d72da4a4d973 Author: Peter Zijlstra <peterz@infradead.org> Date: Wed May 27 11:09:36 2015 +0930 rbtree: Make lockless searches non-fatal Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Link: http://lkml.kernel.org/n/tip-qlnzhezv5ddwst0w9fydju0y@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | Linux 4.2-rc1v4.2-rc1Linus Torvalds2015-07-051-2/+2
| |
* | Merge tag 'platform-drivers-x86-v4.2-2' of ↵Linus Torvalds2015-07-057-45/+1004
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.infradead.org/users/dvhart/linux-platform-drivers-x86 Pull late x86 platform driver updates from Darren Hart: "The following came in a bit later and I wanted them to bake in next a few more days before submitting, thus the second pull. A new intel_pmc_ipc driver, a symmetrical allocation and free fix in dell-laptop, a couple minor fixes, and some updated documentation in the dell-laptop comments. intel_pmc_ipc: - Add Intel Apollo Lake PMC IPC driver tc1100-wmi: - Delete an unnecessary check before the function call "kfree" dell-laptop: - Fix allocating & freeing SMI buffer page - Show info about WiGig and UWB in debugfs - Update information about wireless control" * tag 'platform-drivers-x86-v4.2-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: intel_pmc_ipc: Add Intel Apollo Lake PMC IPC driver tc1100-wmi: Delete an unnecessary check before the function call "kfree" dell-laptop: Fix allocating & freeing SMI buffer page dell-laptop: Show info about WiGig and UWB in debugfs dell-laptop: Update information about wireless control
| * | intel_pmc_ipc: Add Intel Apollo Lake PMC IPC driverqipeng.zha2015-06-295-0/+864
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This driver provides support for PMC control on Apollo Lake platforms. The PMC is an ARC processor which defines some IPC commands for communication with other entities in the CPU. Signed-off-by: qipeng.zha <qipeng.zha@intel.com> [fengguang.wu@intel.com: Fix Sparse and Cocinelle warnings] Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Darren Hart <dvhart@linux.intel.com>
| * | tc1100-wmi: Delete an unnecessary check before the function call "kfree"Markus Elfring2015-06-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kfree() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Darren Hart <dvhart@linux.intel.com>
| * | dell-laptop: Fix allocating & freeing SMI buffer pagePali Rohár2015-06-241-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit fix kernel crash when probing for rfkill devices in dell-laptop driver failed. Function free_page() was incorrectly used on struct page * instead of virtual address of SMI buffer. This commit also simplify allocating page for SMI buffer by using __get_free_page() function instead of sequential call of functions alloc_page() and page_address(). Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: stable@vger.kernel.org Signed-off-by: Darren Hart <dvhart@linux.intel.com>
| * | dell-laptop: Show info about WiGig and UWB in debugfsPali Rohár2015-06-221-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | This commit show additional information about rfkill state in debugfs based on newly released documentation by Dell. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Darren Hart <dvhart@linux.intel.com>
| * | dell-laptop: Update information about wireless controlPali Rohár2015-06-221-39/+119
| | | | | | | | | | | | | | | | | | | | | | | | Make sure that all existing SMBIOS calls for wireless control are properly documented. This commit also add new documentation released by Dell. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Darren Hart <dvhart@linux.intel.com>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2015-07-0499-553/+784
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
| * | | 9p: cope with bogus responses from server in p9_client_{read,write}Al Viro2015-07-041-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | if server claims to have written/read more than we'd told it to, warn and cap the claimed byte count to avoid advancing more than we are ready to.
| * | | p9_client_write(): avoid double p9_free_req()Al Viro2015-07-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Braino in "9p: switch p9_client_write() to passing it struct iov_iter *"; if response is impossible to parse and we discard the request, get the out of the loop right there. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | 9p: forgetting to cancel request on interrupted zero-copy RPCAl Viro2015-07-041-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we'd already sent a request and decide to abort it, we *must* issue TFLUSH properly and not just blindly reuse the tag, or we'll get seriously screwed when response eventually arrives and we confuse it for response to later request that had reused the same tag. Cc: stable@vger.kernel.org # v3.2 and later Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | dax: bdev_direct_access() may sleepMatthew Wilcox2015-07-041-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The brd driver is the only in-tree driver that may sleep currently. After some discussion on linux-fsdevel, we decided that any driver may choose to sleep in its ->direct_access method. To ensure that all callers of bdev_direct_access() are prepared for this, add a call to might_sleep(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | block: Add support for DAX reads/writes to block devicesMatthew Wilcox2015-07-042-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a block device supports the ->direct_access methods, bypass the normal DIO path and use DAX to go straight to memcpy() instead of allocating a DIO and a BIO. Includes support for the DIO_SKIP_DIO_COUNT flag in DAX, as is done in do_blockdev_direct_IO(). Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | dax: Use copy_from_iter_nocacheMatthew Wilcox2015-07-041-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When userspace does a write, there's no need for the written data to pollute the CPU cache. This matches the original XIP code. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | dax: Add block size note to documentationMatthew Wilcox2015-07-041-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For block devices which are small enough, mkfs will default to creating a filesystem with block sizes smaller than page size. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs/file.c: __fget() and dup2() atomicity rulesEric Dumazet2015-07-011-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __fget() does lockless fetch of pointer from the descriptor table, attempts to grab a reference and treats "it was already zero" as "it's already gone from the table, we just hadn't seen the store, let's fail". Unfortunately, that breaks the atomicity of dup2() - __fget() might see the old pointer, notice that it's been already dropped and treat that as "it's closed". What we should be getting is either the old file or new one, depending whether we come before or after dup2(). Dmitry had following test failing sometimes : int fd; void *Thread(void *x) { char buf; int n = read(fd, &buf, 1); if (n != 1) exit(printf("read failed: n=%d errno=%d\n", n, errno)); return 0; } int main() { fd = open("/dev/urandom", O_RDONLY); int fd2 = open("/dev/urandom", O_RDONLY); if (fd == -1 || fd2 == -1) exit(printf("open failed\n")); pthread_t th; pthread_create(&th, 0, Thread, 0); if (dup2(fd2, fd) == -1) exit(printf("dup2 failed\n")); pthread_join(th, 0); if (close(fd) == -1) exit(printf("close failed\n")); if (close(fd2) == -1) exit(printf("close failed\n")); printf("DONE\n"); return 0; } Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | fs/file.c: don't acquire files->file_lock in fd_install()Eric Dumazet2015-07-013-19/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mateusz Guzik reported : Currently obtaining a new file descriptor results in locking fdtable twice - once in order to reserve a slot and second time to fill it. Holding the spinlock in __fd_install() is needed in case a resize is done, or to prevent a resize. Mateusz provided an RFC patch and a micro benchmark : http://people.redhat.com/~mguzik/pipebench.c A resize is an unlikely operation in a process lifetime, as table size is at least doubled at every resize. We can use RCU instead of the spinlock. __fd_install() must wait if a resize is in progress. The resize must block new __fd_install() callers from starting, and wait that ongoing install are finished (synchronize_sched()) resize should be attempted by a single thread to not waste resources. rcu_sched variant is used, as __fd_install() and expand_fdtable() run from process context. It gives us a ~30% speedup using pipebench on a dual Intel(R) Xeon(R) CPU E5-2696 v2 @ 2.50GHz Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Mateusz Guzik <mguzik@redhat.com> Tested-by: Mateusz Guzik <mguzik@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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