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Commit e1abf2cc8d5d80b41c4419368ec743ccadbb131e ("bpf: Fix the build on
BPF_SYSCALL=y && !CONFIG_TRACING kernels, make it more configurable")
updated the building condition of bpf_trace.o from CONFIG_BPF_SYSCALL
to CONFIG_BPF_EVENTS, but the corresponding #ifdef controller in
trace_events.h for trace_call_bpf() was not changed. Which, in theory,
is incorrect.
With current Kconfigs, we can create a .config with CONFIG_BPF_SYSCALL=y
and CONFIG_BPF_EVENTS=n by unselecting CONFIG_KPROBE_EVENT and
selecting CONFIG_BPF_SYSCALL. With these options, trace_call_bpf() will
be defined as an extern function, but if anyone calls it a symbol missing
error will be triggered since bpf_trace.o was not built.
This patch changes the #ifdef controller for trace_call_bpf() from
CONFIG_BPF_SYSCALL to CONFIG_BPF_EVENTS. I'll show its correctness:
Before this patch:
BPF_SYSCALL BPF_EVENTS trace_call_bpf bpf_trace.o
y y normal compiled
n n inline not compiled
y n normal not compiled (incorrect)
n y impossible (BPF_EVENTS depends on BPF_SYSCALL)
After this patch:
BPF_SYSCALL BPF_EVENTS trace_call_bpf bpf_trace.o
y y normal compiled
n n inline not compiled
y n inline not compiled (fixed)
n y impossible (BPF_EVENTS depends on BPF_SYSCALL)
So this patch doesn't break anything. QED.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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It is cumbersome to manually calculate the total time spent in a given
syscall by multiplying the average value with the number of calls.
Instead, we now do this directly inside perf trace.
Note that this is also done by 'strace', which even adds a column with
relative numbers - something we could do in the future.
Example:
perf trace -s find /some/folder > /dev/null
Summary of events:
find (19976), 700123 events, 100.0%, 0.000 msec
syscall calls total min avg max stddev
(msec) (msec) (msec) (msec) (%)
--------------- -------- --------- --------- --------- --------- ------
read 4 0.006 0.001 0.002 0.003 27.42%
write 8046 9.617 0.001 0.001 0.035 0.56%
open 34196 40.384 0.001 0.001 0.071 0.30%
close 68375 57.104 0.001 0.001 0.076 0.25%
stat 4 0.004 0.001 0.001 0.001 3.14%
fstat 34189 27.518 0.001 0.001 0.060 0.34%
mmap 13 0.029 0.001 0.002 0.003 10.74%
mprotect 6 0.018 0.002 0.003 0.005 17.04%
munmap 3 0.014 0.003 0.005 0.006 24.87%
brk 87 0.490 0.001 0.006 0.016 6.50%
ioctl 3 0.004 0.001 0.001 0.003 36.39%
access 1 0.004 0.004 0.004 0.004 0.00%
uname 1 0.001 0.001 0.001 0.001 0.00%
getdents 68393 143.600 0.001 0.002 0.187 0.95%
fchdir 68371 56.980 0.001 0.001 0.111 0.39%
arch_prctl 1 0.001 0.001 0.001 0.001 0.00%
openat 34184 41.737 0.001 0.001 0.102 0.41%
newfstatat 34184 41.180 0.001 0.001 0.064 0.34%
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
LPU-Reference: 1438853069-5902-1-git-send-email-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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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:
New features:
- Deref sys_enter pointer args with contents from probe:vfs_getname, showing
pathnames instead of pointers in many syscalls in 'perf trace'. (Arnaldo Carvalho de Melo)
- Make 'perf trace' write to stderr by default, just like 'strace'. (Milian Woff)
Infrastructure changes:
- color_vfprintf() fixes. (Andi Kleen, Jiri Olsa)
- Allow enabling/disabling PERF_SAMPLE_TIME per event. (Kan Liang)
- Fix build errors with mipsel-linux-uclibc compiler. (Petri Gynther)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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linux/tools$ make ARCH=mips CROSS_COMPILE=mipsel-linux- perf
...
config/Makefile:256: *** No gnu/libc-version.h found, please install
glibc-dev[el]. Stop.
make[1]: *** [all] Error 2
make: *** [perf] Error 2
...
In file included from builtin-sched.c:13:0:
util/cloexec.h:8:12: error: redundant redeclaration of ‘sched_getcpu’
[-Werror=redundant-decls]
extern int sched_getcpu(void) __THROW;
mipsel-buildroot-linux-uclibc/sysroot/usr/include/bits/sched.h:88:12:
note: previous declaration of ‘sched_getcpu’ was here
extern int sched_getcpu (void) __THROW;
uclibc info:
sysroot/usr/include/bits/uClibc_config.h
__UCLIBC_MAJOR__ 0
__UCLIBC_MINOR__ 9
__UCLIBC_SUBLEVEL__ 33
sysroot/usr/include/features.h
__UCLIBC__ 1
__GLIBC__ 2
__GLIBC_MINOR__ 2
Signed-off-by: Petri Gynther <pgynther@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1438735081-24131-1-git-send-email-pgynther@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Without this patch, it is cumbersome to read the trace output but
ignoring the normal, potentially verbose, output of the debuggee. One
common example is doing something like the following:
perf trace -s find /tmp > /dev/null
Without this patch, the trace summary will be lost. Now, it will still
be printed at the end. This behavior is also applied by strace.
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/n/tip-tqnks6y2cnvm5f9g2dsfr7zl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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color_vprintf was including the length of the invisible escape sequences
in its return argument. Don't include them to make the return value
usable for indentation calculations.
v2: Add comment, rebase
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1438649408-20807-3-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Seems like it's always '\n' through color_fprintf_ln, which is not used
at all, removing.. ;-)
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1438649408-20807-2-git-send-email-andi@firstfloor.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Pass global callchain_param into parse_callchain_record_opt and
perf_evsel__config_callgraph as parameter. So we can reuse these
functions to parse/config local param for callchain.
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/1438677022-34296-3-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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This patchkit adds the ability to turn off time stamps per event.
One usaful case for partial time is to work with per-event callgraph to
enable "PEBS threshold > 1" (https://lkml.org/lkml/2015/5/10/196), which
can significantly reduce the sampling overhead.
The event samples with time stamps off will not be ordered.
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/1438677022-34296-2-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Those were covered and tested in this cset:
access, chdir, chmod, chown, chroot, creat, getxattr,
inotify_add_watch, lchown, lgetxattr, listxattr,
lsetxattr, mkdir, mkdirat, mknod, rmdir, faccessat,
newfstatat, openat, readlink, readlinkat, removexattr,
setxattr, statfs, swapon, swapoff, truncate, unlinkat,
utime, utimes, utimensat.
E.g.:
# trace -e statfs,access,mkdir mkdir /tmp/bla
0.285 (0.020 ms): mkdir/2799 access(filename: /etc/ld.so.preload, mode: R ) = -1 ENOENT No such file or directory
1.070 (0.032 ms): mkdir/2799 statfs(pathname: /sys/fs/selinux, buf: 0x7ffeafbdc930) = 0
1.087 (0.013 ms): mkdir/2799 statfs(pathname: /sys/fs/selinux, buf: 0x7ffeafbdc820) = 0
1.189 (0.014 ms): mkdir/2799 access(filename: /etc/selinux/config ) = 0
1.905 (0.610 ms): mkdir/2799 mkdir(pathname: /tmp/bla, mode: 511 ) = 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: Milian Wolff <mail@milianw.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-wbqtnlktquun3wtpjdz3okul@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
and an empty message aborts the commit.
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To work like strace and dereference syscall pointer args we need to
insert probes (or tracepoints) right after we copy those bytes from
userspace.
Since we're formatting the syscall args at raw_syscalls:sys_enter time,
we need to have a formatter that just stores the position where, later,
when we get the probe:vfs_getname, we can insert the pointer contents.
Now, if a probe:vfs_getname with this format is in place:
# perf probe -l
probe:vfs_getname (on getname_flags:72@/home/git/linux/fs/namei.c with pathname)
That was, in this case, put in place with:
# 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
#
Then 'perf trace' will notice that and do the pointer -> contents
expansion:
# trace -e open touch /tmp/bla
0.165 (0.010 ms): touch/17752 open(filename: /etc/ld.so.cache, flags: CLOEXEC) = 3
0.195 (0.011 ms): touch/17752 open(filename: /lib64/libc.so.6, flags: CLOEXEC) = 3
0.512 (0.012 ms): touch/17752 open(filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
0.582 (0.012 ms): touch/17752 open(filename: /tmp/bla, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: 438) = 3
#
Roughly equivalent to strace's output:
# strace -rT -e open touch /tmp/bla
0.000000 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 <0.000039>
0.000317 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 <0.000102>
0.001461 open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3 <0.000072>
0.000405 open("/tmp/bla", O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666) = 3 <0.000055>
0.000641 +++ exited with 0 +++
#
Now we need to either look for at all syscalls that are marked as
pointers and have some well known names ("filename", "pathname", etc)
and set the arg formatter to the one used for the "open" syscall in this
patch.
This implementation works for syscalls with just a string being copied
from userspace, for matching syscalls with more than one string being
copied via the same probe/trace point (vfs_getname) we need to extend
the vfs_getname probe spec to include the pointer too, but there are
some problems with that in 'perf probe' or the kernel kprobes code, need
to investigate before considering supporting multiple strings per
syscall.
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-xvuwx6nuj8cf389kf9s2ue2s@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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We were using it as a magic number, 1024, fix that.
Eventually we need to stop doing it per line, and do it per
arg, traversing the args at output time, to avoid the memmove()
calls that will be used in the next cset to replace pointers
present at raw_syscalls:sys_enter time with its contents that
appear at probe:vfs_getname time, before raw_syscalls:sys_exit
time.
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-4sz3wid39egay1pp8qmbur4u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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So that we can later decide if we will store where to expand the
pathname once we are handling vfs_getname or if we should instead
just go on and straight away print the pointer.
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-ytxk5s5jpc50wahffmlxgxuw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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We were accessing trace->syscalls.events members even when that struct
wasn't initialized, i.e. --no-syscalls was specified on the command
line, fix it to show that, still in debug mode, when we have an event
qualifier list, i.e. when we actually are doing subset syscall tracing.
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>
Fixes: 19867b6186f3 ("perf trace: Use event filters for the event qualifier list")
Link: http://lkml.kernel.org/n/tip-7980ym6vujgh3yiai0cqzc88@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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The libtraceevent handler (session->tevent) is only initialized when
there are tracepoints in a perf.data event list, so do not call
pevent_set_function_resolve() in those cases, fixing a segfault.
Reported-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
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: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-xyynkucl5p4bcs13zi4i4b1f@git.kernel.org
Report-link: http://lkml.kernel.org/r/20150803174113.GA20282@krava.redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Vince Weaver and Stephane Eranian reported warnings in the PEBS
code when running the perf fuzzer. Stephane wrote:
> I can reproduce the problem on my HSW running the fuzzer.
>
> I can see why this could be happening if you are mixing PEBS and non PEBS events
> in the bottom 4 counters. I suspect:
> for (bit = 0; bit < x86_pmu.max_pebs_events; bit++) {
> if ((counts[bit] == 0) && (error[bit] == 0))
> continue;
>
> This test is not correct when you have non-PEBS events mixed with
> PEBS events and they overflow at the same time. They will have
> counts[i] != 0 but error[i] == 0, and thus you fall thru the loop
> and hit the assert. Or it is something along those lines.
The only way I can make this work is if ->status only has !PEBS events
set, because if it has both set we'll take that slow path which masks
out the !PEBS bits.
After masking there are 3 options:
- there is one bit set, and its @bit, we increment counts[bit].
- there are multiple bits set, we increment error[] for each set bit,
we do not increment counts[].
- there are no bits set, we do nothing.
The intent was to never increment counts[] for !PEBS events.
Now if we start out with only a single !PEBS event set, we'll pass the
test and increment counts[] for a !PEBS and hit the warn.
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Stephane Eranian <eranian@google.com>
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: Thomas Gleixner <tglx@linutronix.de>
Cc: kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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When disabling a PEBS event, we need to drain the buffer. Doing so
requires a correct cpuc->pebs_active mask.
The current code clears the pebs_active bit before draining the
buffer. Fix that.
Signed-off-by: "Liang, Kan" <kan.liang@intel.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>
Cc: Vince Weaver<vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/37D7C6CF3E00A74B8858931C1DB2F07701885A65@SHSMSX103.ccr.corp.intel.com
[ Fixed the SOB. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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This patch adds an MSR PMU to support free running MSR counters. Such
as time and freq related counters includes TSC, IA32_APERF, IA32_MPERF
and IA32_PPERF, but also SMI_COUNT.
The events are exposed in sysfs for use by perf stat and other tools.
The files are under /sys/devices/msr/events/
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Kan Liang <kan.liang@intel.com>
[ s/freq/msr/, added SMI_COUNT, fixed bugs. ]
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>
Cc: acme@kernel.org
Cc: adrian.hunter@intel.com
Cc: dsahern@gmail.com
Cc: eranian@google.com
Cc: jolsa@kernel.org
Cc: mark.rutland@arm.com
Cc: namhyung@kernel.org
Link: http://lkml.kernel.org/r/1437407346-31186-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The uncore subsystem for Broadwell-DE is similar to Haswell-EP. There
are some differences in pci device IDs, box number and constraints.
Please refer to the public document:
http://www.intel.com/content/www/us/en/processors/xeon/xeon-d-1500-uncore-performance-monitoring.html
Signed-off-by: Kan Liang <kan.liang@intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1435839172-15114-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The next patch adds a new perf extra register where 0x1ff is not a valid
value. Use 0x11 instead.
Signed-off-by: Andi Kleen <ak@linux.intel.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/1435707205-6676-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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merge_attr() allows to merge two sysfs attribute tables.
Export it to be usable by other files too.
Next patch is going to use that to extend the sysfs format
attributes for a CPU.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1435612935-24425-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In callstack mode the LBR is not a ring buffer, but a stack that grows up
and down. This means in this case we don't need to access all LBRs, only the
ones up to TOS. Do this optimization for the normal LBR read, and the context
switch save/restore code. For save/restore it can be done unconditionally, as
it only runs when call stack mode is active.
This recovers some of the cost of going to 32 LBRs on Skylake.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: acme@kernel.org
Cc: eranian@google.com
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1432786398-23861-6-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Use the correct index to save/restore the LBR_INFO_x MSR in
callstack mode. This is more a cleanup, as even with the wrong
index the register was correctly saved/restored, and also
LBR callgraph mode in perf tools do not really need anything in
LBR_INFO. But still better to use the right index.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: acme@kernel.org
Cc: eranian@google.com
Cc: jolsa@redhat.com
Link: http://lkml.kernel.org/r/1432786398-23861-5-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Add perf core PMU support for future Intel Skylake CPU cores.
The code is based on Haswell/Broadwell.
There is a new cache event list, based on the updated Haswell
event list.
Skylake has removed most counter constraints on basic
events, so the basic constraints table now only has a single
entry (plus the fixed counters).
TSX support and various other setups are all shared with Haswell.
Skylake has 32 LBR entries. Add a new LBR init function
to set this up. The filters are all the same as Haswell.
It also has a new LBR format with a separate LBR_INFO_* MSR,
but that has been already added earlier.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-7-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
In Arch perfmon v4 the GLOBAL_STATUS reset automatically unfreezes
LBRs. So no need to do it manually in the LBR code. Add a check
to skip it.
v2: Move test up to beginning of function.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-9-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
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With Arch Perfmon v4 the PMU ack unfreezes the LBRs. So we need to do
the PMU ack after the LBR reading, otherwise the LBRs would be polluted
by the PMI handler.
This is a minimal change. In principle the ACK could be moved much later.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-10-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
ArchPerfmon v4 has some new status bits in GLOBAL_STATUS.
These need to be ignored when deciding whether a NMI
was an NMI, to avoid eating all NMIs when they
stay set, see:
b292d7a10487 ("perf/x86/intel: ignore CondChgd bit to avoid false NMI handling")
This patch ignores the new ASIF bit, which indicates
that SGX interfered with the PMU, and also the new
LBR freezing bits, which are set when the LBRs get
frozen, plus the existing CondChange (set by JTAG
debuggers and some buggy BIOSes)
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-8-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Add support for the new LBRv5 format used on Intel Skylake CPUs.
The flags for mispredict, abort, in_tx etc. moved to range of separate
LBR_INFO_* MSRs. Teach the LBR code to read those. The original
LBR registers stay the same, except they have full sign
extension now.
LBR_INFO also reports a cycle count to the last branch.
Report the cycle information using the new "cycles" branch_info
output field.
In addition we have to context switch and clear the new INFO
MSRs to avoid any information leaks.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-6-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Intel Skylake supports reporting the time in cycles a branch in the LBR
took, to give a rough indication of the basic block performance.
Export the cycle information in the branch_info structure.
This can be done by just reusing some currently zero padding.
This is just the generic header change. The architecture
still needs to fill it in.
There's no attempt to convert to real time, as we really
want cycles here.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-5-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Add new MSRs (LBR_INFO) and some new MSR bits used by the Intel Skylake
PMU driver.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-4-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
With PEBSv3 the PEBS record contains a time stamp. That means we can allow
free-running PEBS without a PMI even if the user program requested a time stamp.
This avoids the need to use -T to get free running PEBS, and also avoids
any problems with mis-identifying MMAPs later.
Move the free_running_flags state into a variable in x86_pmu and use it.
This only works when no explicit clock_id is set.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: acme@kernel.org
Cc: eranian@google.com
Cc: jolsa@redhat.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1432786398-23861-2-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
PEBSv3 is the same as the existing PEBSv2 used on Haswell,
but it adds a new TSC field. Add support to the generic
PEBS handler to handle the new format, and overwrite
the perf time stamp using the new native_sched_clock_from_tsc().
Right now the time stamp is just slightly more accurate,
as it is nearer the actual event trigger point. With
the PEBS threshold > 1 patchkit it will be much more accurate,
avoid the problems with MMAP mismatches earlier.
The accurate time stamping is only implemented for
the default trace clock for now.
v2: Use _skl prefix. Check for default clock_id.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
PEBSv3 has a raw TSC time stamp in its memory buffer that
later needs to to be converted to perf_clock.
Add a native_sched_clock_from_tsc() that works the same
as native_sched_clock(), but starts with an already given
TSC value.
Paravirt is ignored, it will just get the native clock.
But there isn't a para virtualized PEBS anyway.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1431285767-27027-2-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Intel PT chapter in the new Intel Architecture SDM adds several packets
corresponding enable bits and registers that control packet generation.
Also, additional bits in the Intel PT CPUID leaf were added to enumerate
presence and parameters of these new packets and features.
The packets and enables are:
* CYC: cycle accurate mode, provides the number of cycles elapsed since
previous CYC packet; its presence and available threshold values are
enumerated via CPUID;
* MTC: mini time counter packets, used for tracking TSC time between
full TSC packets; its presence and available resolution options are
enumerated via CPUID;
* PSB packet period is now configurable, available period values are
enumerated via CPUID.
This patch adds corresponding bit and register definitions, pmu driver
capabilities based on CPUID enumeration, new attribute format bits for
the new featurens and extends event configuration validation function
to take these into account.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.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>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1438262131-12725-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Currently, the PT driver zeroes out the status register every time before
starting the event. However, all the writable bits are already taken care
of in pt_handle_status() function, except the new PacketByteCnt field,
which in new versions of PT contains the number of packet bytes written
since the last sync (PSB) packet. Zeroing it out before enabling PT forces
a sync packet to be written. This means that, with the existing code, a
sync packet (PSB and PSBEND, 18 bytes in total) will be generated every
time a PT event is scheduled in.
To avoid these unnecessary syncs and save a WRMSR in the fast path, this
patch changes the default behavior to not clear PacketByteCnt field, so
that the sync packets will be generated with the period specified as
"psb_period" attribute config field. This has little impact on the trace
data as the other packets that are normally sent within PSB+ (between PSB
and PSBEND) have their own generation scenarios which do not depend on the
sync packets.
One exception where we do need to force PSB like this when tracing starts,
so that the decoder has a clear sync point in the trace. For this purpose
we aready have hw::itrace_started flag, which we are currently using to
output PERF_RECORD_ITRACE_START. This patch moves setting itrace_started
from perf core to the pmu::start, where it should still be 0 on the very
first run.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.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>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1438264104-16189-1-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The check looked wrong, although I think it was actually safe. TASK_SIZE
is unnecessarily small for compat tasks, and it wasn't possible to make
a range breakpoint so large it started in user space and ended in kernel
space.
Nonetheless, let's fix up the check for the benefit of future
readers. A breakpoint is in the kernel if either end is in the
kernel.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/136be387950e78f18cea60e9d1bef74465d0ee8f.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Range breakpoints will do the wrong thing if the address isn't
aligned. While we're there, add comments about why it's safe for
instruction breakpoints.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/ae25d14d61f2f43b78e0a247e469f3072df7e201.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Code on the kprobe blacklist doesn't want unexpected int3
exceptions. It probably doesn't want unexpected debug exceptions
either. Be safe: disallow breakpoints in nokprobes code.
On non-CONFIG_KPROBES kernels, there is no kprobe blacklist. In
that case, disallow kernel breakpoints entirely.
It will be particularly important to keep hw breakpoints out of the
entry and NMI code once we move debug exceptions off the IST stack.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/e14b152af99640448d895e3c2a8c2d5ee19a1325.1438312874.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
AVG_LATENCY(bit 38) is only available on MSR_OFFCORE_RSP0.
So the bit should be removed from RSP1 valid_mask.
Since RSP0 and RSP1 may have different valid_mask, intel_alt_er should
validate the config on the alternate offcore reg before replacing it.
Signed-off-by: Kan Liang <kan.liang@intel.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/1435170215-5017-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The x86_lbr_exclusive commit (4807034248be "perf/x86: Mark Intel PT and
LBR/BTS as mutually exclusive") mistakenly moved intel_pmu_needs_lbr_smpl()
to perf_event.h, while another commit (a46a2300019 "perf: Simplify the
branch stack check") removed it in favor of needs_branch_stack().
This patch gets rid of intel_pmu_needs_lbr_smpl() for good.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.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>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1435140349-32588-3-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Both intel_pmu_enable_bts() and intel_pmu_disable_bts() are in perf_event.h
header file, no need to have them declared again in the driver.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.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>
Cc: acme@infradead.org
Cc: adrian.hunter@intel.com
Cc: hpa@zytor.com
Link: http://lkml.kernel.org/r/1435140349-32588-2-git-send-email-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Haswell and Broadwell have the same uncore CBOX/ARB PMU as Sandy Bridge.
Add the respective model numbers to enable the SNB uncore PMU.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1434347862-28490-2-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Add a new "ARB" uncore PMU that is used to monitor the uncore queue
arbiter. This is useful to measure uncore queue occupancy and similar
statistics. The registers all have the same format as the
existing CBOX PMU.
Also move the event constraints from the CBOX to ARB. The 0x80+
events are ARB events and cannot be scheduled on a CBOX PMU.
Signed-off-by: Andi Kleen <ak@linux.intel.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>
Cc: eranian@google.com
Cc: kan.liang@intel.com
Link: http://lkml.kernel.org/r/1434347862-28490-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The DEFINE_PCI_DEVICE_TABLE() macro is deprecated. Use
'struct pci_device_id' instead of DEFINE_PCI_DEVICE_TABLE(),
with the goal of getting rid of this macro completely.
This Coccinelle semantic patch performs this transformation:
@@
identifier a;
declarer name DEFINE_PCI_DEVICE_TABLE;
initializer i;
@@
- DEFINE_PCI_DEVICE_TABLE(a)
+ const struct pci_device_id a[] = i;
Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
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/20150717052759.GA6265@vaishali-Ideapad-Z570
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Knights Landing DRAM RAPL supports PKG and DRAM RAPL domains.
DRAM RAPL has a different fixed energy unit (2^-16J) similar to
that of HSW.
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Stephane Eranian <eranian@google.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jacob Pan Jun <jacob.jun.pan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nikhil Rao <nikhil.rao@intel.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/aa63b4a3af3160152fea1a10c807f4200527280c.1432665809.git.dasaratharaman.chandramouli@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
The xol_free_insn_slot()->waitqueue_active() check is buggy. We
need mb() after we set the conditon for wait_event(), or
xol_take_insn_slot() can miss the wakeup.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134036.GA4799@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Change xol_add_vma() to use _install_special_mapping(), this way
we can name the vma installed by uprobes. Currently it looks
like private anonymous mapping, this is confusing and
complicates the debugging. With this change /proc/$pid/maps
reports "[uprobes]".
As a side effect this will cause core dumps to include the XOL vma
and I think this is good; this can help to debug the problem if
the app crashed because it was probed.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134033.GA4796@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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install_special_mapping(pages) expects that "pages" is the zero-
terminated array while xol_add_vma() passes &area->page, this
means that special_mapping_fault() can wrongly use the next
member in xol_area (vaddr) as "struct page *".
Fortunately, this area is not expandable so pgoff != 0 isn't
possible (modulo bugs in special_mapping_vmops), but still this
does not look good.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Pratyush Anand <panand@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150721134031.GA4789@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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The previous change documents that cleanup_return_instances()
can't always detect the dead frames, the stack can grow. But
there is one special case which imho worth fixing:
arch_uretprobe_is_alive() can return true when the stack didn't
actually grow, but the next "call" insn uses the already
invalidated frame.
Test-case:
#include <stdio.h>
#include <setjmp.h>
jmp_buf jmp;
int nr = 1024;
void func_2(void)
{
if (--nr == 0)
return;
longjmp(jmp, 1);
}
void func_1(void)
{
setjmp(jmp);
func_2();
}
int main(void)
{
func_1();
return 0;
}
If you ret-probe func_1() and func_2() prepare_uretprobe() hits
the MAX_URETPROBE_DEPTH limit and "return" from func_2() is not
reported.
When we know that the new call is not chained, we can do the
more strict check. In this case "sp" points to the new ret-addr,
so every frame which uses the same "sp" must be dead. The only
complication is that arch_uretprobe_is_alive() needs to know was
it chained or not, so we add the new RP_CHECK_CHAIN_CALL enum
and change prepare_uretprobe() to pass RP_CHECK_CALL only if
!chained.
Note: arch_uretprobe_is_alive() could also re-read *sp and check
if this word is still trampoline_vaddr. This could obviously
improve the logic, but I would like to avoid another
copy_from_user() especially in the case when we can't avoid the
false "alive == T" positives.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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/20150721134028.GA4786@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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arch/x86 doesn't care (so far), but as Pratyush Anand pointed
out other architectures might want why arch_uretprobe_is_alive()
was called and use different checks depending on the context.
Add the new argument to distinguish 2 callers.
Tested-by: Pratyush Anand <panand@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Anton Arapov <arapov@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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/20150721134026.GA4779@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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