<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/tools/perf/bench, branch master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/tools/perf/bench?h=master</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/tools/perf/bench?h=master'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-10-04T11:55:19Z</updated>
<entry>
<title>perf bench: Update use of pthread mutex/cond</title>
<updated>2022-10-04T11:55:19Z</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2022-08-26T16:42:26Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=a64d3af5d9eca3058ab6e0d3715ff36e4d6b5983'/>
<id>urn:sha1:a64d3af5d9eca3058ab6e0d3715ff36e4d6b5983</id>
<content type='text'>
Switch to the use of mutex wrappers that provide better error checking.

Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Reviewed-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexandre Truong &lt;alexandre.truong@arm.com&gt;
Cc: Alexey Bayduraev &lt;alexey.v.bayduraev@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Andres Freund &lt;andres@anarazel.de&gt;
Cc: Andrii Nakryiko &lt;andrii@kernel.org&gt;
Cc: André Almeida &lt;andrealmeid@igalia.com&gt;
Cc: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Cc: Colin Ian King &lt;colin.king@intel.com&gt;
Cc: Dario Petrillo &lt;dario.pk1@gmail.com&gt;
Cc: Darren Hart &lt;dvhart@infradead.org&gt;
Cc: Dave Marchevsky &lt;davemarchevsky@fb.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Fangrui Song &lt;maskray@google.com&gt;
Cc: Hewenliang &lt;hewenliang4@huawei.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Jason Wang &lt;wangborong@cdjrlc.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Martin Liška &lt;mliska@suse.cz&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Cc: Pavithra Gurushankar &lt;gpavithrasha@gmail.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Quentin Monnet &lt;quentin@isovalent.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Cc: Remi Bernon &lt;rbernon@codeweavers.com&gt;
Cc: Riccardo Mancini &lt;rickyman7@gmail.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Tom Rix &lt;trix@redhat.com&gt;
Cc: Weiguo Li &lt;liwg06@foxmail.com&gt;
Cc: Wenyu Liu &lt;liuwenyu7@huawei.com&gt;
Cc: William Cohen &lt;wcohen@redhat.com&gt;
Cc: Zechuan Chen &lt;chenzechuan1@huawei.com&gt;
Cc: bpf@vger.kernel.org
Cc: llvm@lists.linux.dev
Cc: yaowenbin &lt;yaowenbin1@huawei.com&gt;
Link: https://lore.kernel.org/r/20220826164242.43412-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'torvalds/master' into perf/core</title>
<updated>2022-05-23T12:32:49Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-05-23T12:32:49Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=0869331fbaa2c11c9e94e45305d17ce447189a0a'/>
<id>urn:sha1:0869331fbaa2c11c9e94e45305d17ce447189a0a</id>
<content type='text'>
To get the rest of 5.18.

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench numa: Address compiler error on s390</title>
<updated>2022-05-21T17:45:19Z</updated>
<author>
<name>Thomas Richter</name>
<email>tmricht@linux.ibm.com</email>
</author>
<published>2022-05-20T08:11:58Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=f8ac1c478424a9a14669b8cef7389b1e14e5229d'/>
<id>urn:sha1:f8ac1c478424a9a14669b8cef7389b1e14e5229d</id>
<content type='text'>
The compilation on s390 results in this error:

  # make DEBUG=y bench/numa.o
  ...
  bench/numa.c: In function ‘__bench_numa’:
  bench/numa.c:1749:81: error: ‘%d’ directive output may be truncated
              writing between 1 and 11 bytes into a region of size between
              10 and 20 [-Werror=format-truncation=]
  1749 |        snprintf(tname, sizeof(tname), "process%d:thread%d", p, t);
                                                               ^~
  ...
  bench/numa.c:1749:64: note: directive argument in the range
                 [-2147483647, 2147483646]
  ...
  #

The maximum length of the %d replacement is 11 characters because of the
negative sign.  Therefore extend the array by two more characters.

Output after:

  # make  DEBUG=y bench/numa.o &gt; /dev/null 2&gt;&amp;1; ll bench/numa.o
  -rw-r--r-- 1 root root 418320 May 19 09:11 bench/numa.o
  #

Fixes: 3aff8ba0a4c9c919 ("perf bench numa: Avoid possible truncation when using snprintf()")
Suggested-by: Namhyung Kim &lt;namhyung@gmail.com&gt;
Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: https://lore.kernel.org/r/20220520081158.2990006-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench breakpoint: Fix build on 32-bit arches</title>
<updated>2022-05-17T00:23:09Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-05-17T00:18:11Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=df36d2572e0515dc190459489c159b78bb3a21fc'/>
<id>urn:sha1:df36d2572e0515dc190459489c159b78bb3a21fc</id>
<content type='text'>
Cast pointers to unsigned long instead of to uint64_t to avoid this
problem on 32-bit arches:

  31     6.89 debian:experimental-x-mips    : FAIL gcc version 11.2.0 (Debian 11.2.0-18)
    bench/breakpoint.c: In function 'breakpoint_setup':
    bench/breakpoint.c:56:24: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
       56 |         attr.bp_addr = (uint64_t)addr;
          |                        ^
    cc1: all warnings being treated as errors
    make[3]: *** [/git/perf-5.18.0-rc7/tools/build/Makefile.build:139: bench] Error 2

Fixes: 68a6772f11dbb1ed ("perf bench: Add breakpoint benchmarks")
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Dmitriy Vyukov &lt;dvyukov@google.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/YoLq1nHx1doi+VWl@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'torvalds/master' into perf/core</title>
<updated>2022-05-16T13:14:59Z</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-05-16T13:14:59Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=c5468a28efde5978644f1a7eef67780abcd16340'/>
<id>urn:sha1:c5468a28efde5978644f1a7eef67780abcd16340</id>
<content type='text'>
To pick up fixes from perf/urgent.

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench: Add breakpoint benchmarks</title>
<updated>2022-05-13T14:00:38Z</updated>
<author>
<name>Dmitry Vyukov</name>
<email>dvyukov@google.com</email>
</author>
<published>2022-05-05T15:57:45Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=68a6772f11dbb1ed8b74d4c8adc2da1f84dd32a6'/>
<id>urn:sha1:68a6772f11dbb1ed8b74d4c8adc2da1f84dd32a6</id>
<content type='text'>
Add 2 benchmarks:

1. Performance of thread creation/exiting in presence of breakpoints.
2. Performance of breakpoint modification in presence of threads.

The benchmarks capture use cases that we are interested in:
using inheritable breakpoints in large highly-threaded applications.

The benchmarks show significant slowdown imposed by breakpoints
(even when they don't fire).

Testing on Intel 8173M with 112 HW threads show:

  perf bench --repeat=56 breakpoint thread --breakpoints=0 --parallelism=56 --threads=20
        78.675000 usecs/op
  perf bench --repeat=56 breakpoint thread --breakpoints=4 --parallelism=56 --threads=20
     12967.135714 usecs/op

That's 165x slowdown due to presence of the breakpoints.

  perf bench --repeat=20000 breakpoint enable --passive=0 --active=0
         1.433250 usecs/op
  perf bench --repeat=20000 breakpoint enable --passive=224 --active=0
       585.318400 usecs/op
  perf bench --repeat=20000 breakpoint enable --passive=0 --active=111
       635.953000 usecs/op

That's 408x and 444x slowdown due to presence of threads.

Profiles show some overhead in toggle_bp_slot,
but also very high contention:

    90.83%  breakpoint-thre  [kernel.kallsyms]  [k] osq_lock
     4.69%  breakpoint-thre  [kernel.kallsyms]  [k] mutex_spin_on_owner
     2.06%  breakpoint-thre  [kernel.kallsyms]  [k] __reserve_bp_slot
     2.04%  breakpoint-thre  [kernel.kallsyms]  [k] toggle_bp_slot

    79.01%  breakpoint-enab  [kernel.kallsyms]  [k] smp_call_function_single
     9.94%  breakpoint-enab  [kernel.kallsyms]  [k] llist_add_batch
     5.70%  breakpoint-enab  [kernel.kallsyms]  [k] _raw_spin_lock_irq
     1.84%  breakpoint-enab  [kernel.kallsyms]  [k] event_function_call
     1.12%  breakpoint-enab  [kernel.kallsyms]  [k] send_call_function_single_ipi
     0.37%  breakpoint-enab  [kernel.kallsyms]  [k] generic_exec_single
     0.24%  breakpoint-enab  [kernel.kallsyms]  [k] __perf_event_disable
     0.20%  breakpoint-enab  [kernel.kallsyms]  [k] _perf_event_enable
     0.18%  breakpoint-enab  [kernel.kallsyms]  [k] toggle_bp_slot

Committer notes:

Fixup struct init for older compilers:

   3    32.90 alpine:3.5                    : FAIL clang version 3.8.1 (tags/RELEASE_381/final)
    bench/breakpoint.c:49:34: error: missing field 'size' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_event_attr attr = {0};
                                            ^
    1 error generated.
   7    37.31 alpine:3.9                    : FAIL gcc version 8.3.0 (Alpine 8.3.0)
    bench/breakpoint.c:49:34: error: missing field 'size' initializer [-Werror,-Wmissing-field-initializers]
            struct perf_event_attr attr = {0};
                                            ^
    1 error generated.

Signed-off-by: Dmitriy Vyukov &lt;dvyukov@google.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Marco Elver &lt;elver@google.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: https://lore.kernel.org/r/20220505155745.1690906-1-dvyukov@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench: Fix two numa NDEBUG warnings</title>
<updated>2022-05-09T00:48:49Z</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2022-04-28T20:29:11Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=183d4f2d23acecb29695f4d07427c8594e3a9691'/>
<id>urn:sha1:183d4f2d23acecb29695f4d07427c8594e3a9691</id>
<content type='text'>
BUG_ON is a no-op if NDEBUG is defined, otherwise it is an assert.
Compiling with NDEBUG yields:

  bench/numa.c: In function ‘bind_to_cpu’:
  bench/numa.c:314:1: error: control reaches end of non-void function [-Werror=return-type]
    314 | }
        | ^
  bench/numa.c: In function ‘bind_to_node’:
  bench/numa.c:367:1: error: control reaches end of non-void function [-Werror=return-type]
    367 | }
        | ^

Add return statements to cover this case.

Reviewed-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Xing Zhengjun &lt;zhengjun.xing@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220428202912.1056444-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench: Fix numa bench to fix usage of affinity for machines with #CPUs &gt; 1K</title>
<updated>2022-04-14T12:15:10Z</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2022-04-12T16:40:59Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=f58faed7fb3f784efdbf3b401368dcf51a6e28fa'/>
<id>urn:sha1:f58faed7fb3f784efdbf3b401368dcf51a6e28fa</id>
<content type='text'>
The 'perf bench numa' testcase fails on systems with more than 1K CPUs.

Testcase: perf bench numa mem -p 1 -t 3 -P 512 -s 100 -zZ0qcm --thp  1

Snippet of code:

  &lt;&lt;&gt;&gt;
  perf: bench/numa.c:302: bind_to_node: Assertion `!(ret)' failed.
  Aborted (core dumped)
  &lt;&lt;&gt;&gt;

bind_to_node() uses "sched_getaffinity" to save the original cpumask and
this call is returning EINVAL ((invalid argument).

This happens because the default mask size in glibc is 1024.  To
overcome this 1024 CPUs mask size limitation of cpu_set_t, change the
mask size using the CPU_*_S macros ie, use CPU_ALLOC to allocate
cpumask, CPU_ALLOC_SIZE for size.

Apart from fixing this for "orig_mask", apply same logic to "mask" as
well which is used to setaffinity so that mask size is large enough to
represent number of possible CPU's in the system.

sched_getaffinity is used in one more place in perf numa bench. It is in
"bind_to_cpu" function. Apply the same logic there also. Though
currently no failure is reported from there, it is ideal to change
getaffinity to work with such system configurations having CPU's more
than default mask size supported by glibc.

Also fix "sched_setaffinity" to use mask size which is large enough to
represent number of possible CPU's in the system.

Fixed all places where "bind_cpumask" which is part of "struct
thread_data" is used such that bind_cpumask works in all configuration.

Reported-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Signed-off-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Nageswara R Sastry &lt;rnsastry@linux.ibm.com&gt;
Cc: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220412164059.42654-3-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench: Fix numa testcase to check if CPU used to bind task is online</title>
<updated>2022-04-14T12:13:41Z</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2022-04-12T16:40:58Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=8cb7a188ac33b71ec24a9081d1521f46dcab53c4'/>
<id>urn:sha1:8cb7a188ac33b71ec24a9081d1521f46dcab53c4</id>
<content type='text'>
Perf numa bench test fails with error:

Testcase:

  ./perf bench numa mem -p 2 -t 1 -P 1024 -C 0,8 -M 1,0 -s 20 -zZq --thp  1 --no-data_rand_walk

Failure snippet:

&lt;&lt;&gt;&gt;
  Running 'numa/mem' benchmark:

  # Running main, "perf bench numa numa-mem -p 2 -t 1 -P 1024 -C 0,8 -M 1,0 -s 20 -zZq --thp 1 --no-data_rand_walk"

  perf: bench/numa.c:333: bind_to_cpumask: Assertion `!(ret)' failed.
&lt;&lt;&gt;&gt;

The Testcases uses CPU's 0 and 8. In function "parse_setup_cpu_list",
There is check to see if cpu number is greater than max cpu's possible
in the system ie via "if (bind_cpu_0 &gt;= g-&gt;p.nr_cpus || bind_cpu_1 &gt;=
g-&gt;p.nr_cpus) {".

But it could happen that system has say 48 CPU's, but only number of
online CPU's is 0-7. Other CPU's are offlined. Since "g-&gt;p.nr_cpus" is
48, so function will go ahead and set bit for CPU 8 also in cpumask (
td-&gt;bind_cpumask).

bind_to_cpumask function is called to set affinity using
sched_setaffinity and the cpumask. Since the CPU8 is not present, set
affinity will fail here with EINVAL.

Fix this issue by adding a check to make sure that, CPU's provided in
the input argument values are online before proceeding further and skip
the test. For this, include new helper function "is_cpu_online" in
"tools/perf/util/header.c".

Since "BIT(x)" definition will get included from header.h, remove
that from bench/numa.c

Reported-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Signed-off-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Nageswara R Sastry &lt;rnsastry@linux.ibm.com&gt;
Cc: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220412164059.42654-2-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf bench: Fix epoll bench to correct usage of affinity for machines with #CPUs &gt; 1K</title>
<updated>2022-04-09T15:34:29Z</updated>
<author>
<name>Athira Rajeev</name>
<email>atrajeev@linux.vnet.ibm.com</email>
</author>
<published>2022-04-06T17:51:11Z</published>
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The 'perf bench epoll' testcase fails on systems with more than 1K CPUs.

Testcase: perf bench epoll all

Result snippet:
&lt;&lt;&gt;&gt;
Run summary [PID 106497]: 1399 threads monitoring on 64 file-descriptors for 8 secs.

perf: pthread_create: No such file or directory
&lt;&lt;&gt;&gt;

In epoll benchmarks (ctl, wait) pthread_create is invoked in do_threads
from respective bench_epoll_*  function. Though the logs shows direct
failure from pthread_create, the actual failure is from
"sched_setaffinity" returning EINVAL (invalid argument).

This happens because the default mask size in glibc is 1024. To overcome
this 1024 CPUs mask size limitation of cpu_set_t, change the mask size
using the CPU_*_S macros.

Patch addresses this by fixing all the epoll benchmarks to use CPU_ALLOC
to allocate cpumask, CPU_ALLOC_SIZE for size, and CPU_SET_S to set the
mask.

Reported-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Signed-off-by: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Tested-by: Disha Goel &lt;disgoel@linux.vnet.ibm.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kajol Jain &lt;kjain@linux.ibm.com&gt;
Cc: Madhavan Srinivasan &lt;maddy@linux.vnet.ibm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Nageswara R Sastry &lt;rnsastry@linux.ibm.com&gt;
Cc: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20220406175113.87881-3-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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