Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 31 7月, 2020 1 次提交
    • T
      tools build feature: Use CC and CXX from parent · e3232c2f
      由 Thomas Hebb 提交于 
      commit c8c18867 ("tools build: Use the same CC for feature detection
and actual build") changed these assignments from unconditional (:=) to
conditional (?=) so that they wouldn't clobber values from the
environment. However, conditional assignment does not work properly for
variables that Make implicitly sets, among which are CC and CXX. To
quote tools/scripts/Makefile.include, which handles this properly:

  # Makefiles suck: This macro sets a default value of $(2) for the
  # variable named by $(1), unless the variable has been set by
  # environment or command line. This is necessary for CC and AR
  # because make sets default values, so the simpler ?= approach
  # won't work as expected.

In other words, the conditional assignments will not run even if the
variables are not overridden in the environment; Make will set CC to
"cc" and CXX to "g++" when it starts[1], meaning the variables are not
empty by the time the conditional assignments are evaluated. This breaks
cross-compilation when CROSS_COMPILE is set but CC isn't, since "cc"
gets used for feature detection instead of the cross compiler (and
likewise for CXX).

To fix the issue, just pass down the values of CC and CXX computed by
the parent Makefile, which gets included by the Makefile that actually
builds whatever we're detecting features for and so is guaranteed to
have good values. This is a better solution anyway, since it means we
aren't trying to replicate the logic of the parent build system and so
don't risk it getting out of sync.

Leave PKG_CONFIG alone, since 1) there's no common logic to compute it
in Makefile.include, and 2) it's not an implicit variable, so
conditional assignment works properly.

[1] https://www.gnu.org/software/make/manual/html_node/Implicit-Variables.html

Fixes: c8c18867 ("tools build: Use the same CC for feature detection and actual build")
Signed-off-by: NThomas Hebb <tommyhebb@gmail.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Igor Lubashev <ilubashe@akamai.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: thomas hebb <tommyhebb@gmail.com>
Link: http://lore.kernel.org/lkml/0a6e69d1736b0fa231a648f50b0cce5d8a6734ef.1595822871.git.tommyhebb@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      e3232c2f
  3. 30 7月, 2020 24 次提交
  5. 28 7月, 2020 1 次提交
    • D
      perf bench: Add basic syscall benchmark · c2a08203
      由 Davidlohr Bueso 提交于 
      The usefulness of having a standard way of testing syscall performance
has come up from time to time[0]. Furthermore, some of our testing
machinery (such as 'mmtests') already makes use of a simplified version
of the microbenchmark. This patch mainly takes the same idea to measure
syscall throughput compatible with 'perf-bench' via getppid(2), yet
without any of the additional template stuff from Ingo's version (based
on numa.c). The code is identical to what mmtests uses.

[0] https://lore.kernel.org/lkml/20160201074156.GA27156@gmail.com/

Committer notes:

Add mising stdlib.h and unistd.h to get the prototypes for exit() and
getppid().

Committer testing:

  $ perf bench
  Usage:
  	perf bench [<common options>] <collection> <benchmark> [<options>]

          # List of all available benchmark collections:

           sched: Scheduler and IPC benchmarks
         syscall: System call benchmarks
             mem: Memory access benchmarks
            numa: NUMA scheduling and MM benchmarks
           futex: Futex stressing benchmarks
           epoll: Epoll stressing benchmarks
       internals: Perf-internals benchmarks
             all: All benchmarks

  $
  $ perf bench syscall

          # List of available benchmarks for collection 'syscall':

           basic: Benchmark for basic getppid(2) calls
             all: Run all syscall benchmarks

  $ perf bench syscall basic
  # Running 'syscall/basic' benchmark:
  # Executed 10000000 getppid() calls
       Total time: 3.679 [sec]

         0.367957 usecs/op
          2717708 ops/sec
  $ perf bench syscall all
  # Running syscall/basic benchmark...
  # Executed 10000000 getppid() calls
       Total time: 3.644 [sec]

         0.364456 usecs/op
          2743815 ops/sec

  $
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Acked-by: NJosh Poimboeuf <jpoimboe@redhat.com>
Acked-by: NMel Gorman <mgorman@techsingularity.net>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20190308181747.l36zqz2avtivrr3c@linux-r8p5Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c2a08203
  7. 22 7月, 2020 8 次提交
  9. 21 7月, 2020 3 次提交
  11. 17 7月, 2020 3 次提交
    • J
      perf metric: Add 'struct expr_id_data' to keep expr value · 070b3b5a
      由 Jiri Olsa 提交于 
      Add 'struct expr_id_data' to keep an expr value instead of just a simple
double pointer, so we can store more data for ID in the following
changes.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200712132634.138901-3-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      070b3b5a
    • J
      perf metric: Rename expr__add_id() to expr__add_val() · 2c46f542
      由 Jiri Olsa 提交于 
      Rename expr__add_id() to expr__add_val() so we can use expr__add_id() to
actually add just the id without any value in following changes.

There's no functional change.
Signed-off-by: NJiri Olsa <jolsa@kernel.org>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200712132634.138901-2-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      2c46f542
    • M
      perf probe: Warn if the target function is a GNU indirect function · 3de2bf9d
      由 Masami Hiramatsu 提交于 
      Warn if the probe target function is a GNU indirect function (GNU_IFUNC)
because it may not be what the user wants to probe.

The GNU indirect function ( https://sourceware.org/glibc/wiki/GNU_IFUNC )
is the dynamic symbol solved at runtime. An IFUNC function is a selector
which is invoked from the ELF loader, but the symbol address of the
function which will be modified by the IFUNC is the same as the IFUNC in
the symbol table. This can confuse users trying to probe such functions.

For example, memcpy is an IFUNC.

  probe_libc:memcpy    (on __new_memcpy_ifunc@x86_64/multiarch/memcpy.c in /usr/lib64/libc-2.30.so)

the probe is put on an IFUNC.

  perf  1742 [000] 26201.715632: probe_libc:memcpy: (7fdaa53824c0)
              7fdaa53824c0 __new_memcpy_ifunc+0x0 (inlined)
              7fdaa5d4a980 elf_machine_rela+0x6c0 (inlined)
              7fdaa5d4a980 elf_dynamic_do_Rela+0x6c0 (inlined)
              7fdaa5d4a980 _dl_relocate_object+0x6c0 (/usr/lib64/ld-2.30.so)
              7fdaa5d42155 dl_main+0x1cc5 (/usr/lib64/ld-2.30.so)
              7fdaa5d5831a _dl_sysdep_start+0x54a (/usr/lib64/ld-2.30.so)
              7fdaa5d3ffeb _dl_start_final+0x25b (inlined)
              7fdaa5d3ffeb _dl_start+0x25b (/usr/lib64/ld-2.30.so)
              7fdaa5d3f117 .annobin_rtld.c+0x7 (inlined)

And the event is invoked from the ELF loader instead of the target
program's main code.

Moreover, at this moment, we can not probe on the function which will
be selected by the IFUNC, because it is determined at runtime. But
uprobe will be prepared before running the target binary.

Thus, I decided to warn user when 'perf probe' detects that the probe
point is on an GNU IFUNC symbol. Someone who wants to probe an IFUNC
symbol to debug the IFUNC function can ignore this warning.

Committer notes:

I.e., this warning will be emitted if the probe point is an IFUNC:

  "Warning: The probe function (%s) is a GNU indirect function.\n"
  "Consider identifying the final function used at run time and set the probe directly on that.\n"

Complete set of steps:

  # readelf -sW /lib64/libc-2.29.so  | grep IFUNC | tail
   22196: 0000000000109a80   183 IFUNC   GLOBAL DEFAULT   14 __memcpy_chk
   22214: 00000000000b7d90   191 IFUNC   GLOBAL DEFAULT   14 __gettimeofday
   22336: 000000000008b690    60 IFUNC   GLOBAL DEFAULT   14 memchr
   22350: 000000000008b9b0    89 IFUNC   GLOBAL DEFAULT   14 __stpcpy
   22420: 000000000008bb10    76 IFUNC   GLOBAL DEFAULT   14 __strcasecmp_l
   22582: 000000000008a970    60 IFUNC   GLOBAL DEFAULT   14 strlen
   22585: 00000000000a54d0    92 IFUNC   WEAK   DEFAULT   14 wmemset
   22600: 000000000010b030    92 IFUNC   GLOBAL DEFAULT   14 __wmemset_chk
   22618: 000000000008b8a0   183 IFUNC   GLOBAL DEFAULT   14 __mempcpy
   22675: 000000000008ba70    76 IFUNC   WEAK   DEFAULT   14 strcasecmp
  #
  # perf probe -x /lib64/libc-2.29.so strlen
  Warning: The probe function (strlen) is a GNU indirect function.
  Consider identifying the final function used at run time and set the probe directly on that.
  Added new event:
    probe_libc:strlen    (on strlen in /usr/lib64/libc-2.29.so)

  You can now use it in all perf tools, such as:

  	perf record -e probe_libc:strlen -aR sleep 1

  #
Reported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lore.kernel.org/lkml/159438669349.62703.5978345670436126948.stgit@devnote2Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      3de2bf9d