[PATCH v1 0/3] perf record: adapt NUMA awareness to machines with #CPUs > 1K

[Alexey Budankov]

Current implementation of cpu_set_t type by glibc has internal cpu
mask size limitation of no more than 1024 CPUs. This limitation confines
NUMA awareness of Perf tool in record mode, thru --affinity option,
to the first 1024 CPUs on machines with larger amount of CPUs.

This patch set enables Perf tool to overcome 1024 CPUs limitation by
using a dedicated struct mmap_cpu_mask type and applying tool's bitmap
API operations to manipulate affinity masks of the tool's thread and
the mmaped data buffers.

tools bitmap API has been extended with bitmap_equal() operation
and its implementation is derived from the kernel one.

---
Alexey Budankov (3):
  tools bitmap: extend bitmap API with bitmap_equal()
  perf mmap: declare type for cpu mask of arbitrary length
  perf record: adapt affinity to machines with #CPUs > 1K

 tools/include/linux/bitmap.h | 21 +++++++++++++++++++++
 tools/lib/bitmap.c           | 15 +++++++++++++++
 tools/perf/builtin-record.c  | 28 ++++++++++++++++++++++------
 tools/perf/util/mmap.c       | 28 ++++++++++++++++++++++------
 tools/perf/util/mmap.h       | 11 ++++++++++-
 5 files changed, 90 insertions(+), 13 deletions(-)

---
Testing:

  $ tools/perf/perf record -v --affinity=cpu -- ls
  thread mask[8]: empty
  Using CPUID GenuineIntel-6-5E-3
  ...
  mmap size 528384B
  0x7f95f8f85010: mmap mask[8]: 0
  0x7f95f8f950d8: mmap mask[8]: 1
  0x7f95f8fa51a0: mmap mask[8]: 2
  0x7f95f8fb5268: mmap mask[8]: 3
  0x7f95f8fc5330: mmap mask[8]: 4
  0x7f95f8fd53f8: mmap mask[8]: 5
  0x7f95f8fe54c0: mmap mask[8]: 6
  0x7f95f8ff5588: mmap mask[8]: 7
  ...
  thread mask[8]: 0
  thread mask[8]: 1
  thread mask[8]: 2
  thread mask[8]: 3
  arch			      copy     Documentation  init     kernel	 MAINTAINERS	  modules.builtin.modinfo  perf.data	  scripts   System.map	vmlinux
  block			      COPYING  drivers	      ipc      lbuild	 Makefile	  modules.order		   perf.data.old  security  tools	vmlinux.o
  certs			      CREDITS  fs	      Kbuild   lib	 mm		  Module.symvers	   README	  sound     usr
  config-5.2.7-100.fc29.x86_64  crypto   include	      Kconfig  LICENSES  modules.builtin  net			   samples	  stdio     virt
  thread mask[8]: 4
  thread mask[8]: 5
  thread mask[8]: 6
  thread mask[8]: 7
  thread mask[8]: 0
  thread mask[8]: 1
  thread mask[8]: 2
  thread mask[8]: 3
  thread mask[8]: 4
  thread mask[8]: 5
  thread mask[8]: 6
  thread mask[8]: 7
  [ perf record: Woken up 0 times to write data ]
  thread mask[8]: 0
  thread mask[8]: 1
  thread mask[8]: 2
  thread mask[8]: 3
  thread mask[8]: 4
  thread mask[8]: 5
  thread mask[8]: 6
  thread mask[8]: 7
  ...
  [ perf record: Captured and wrote 0.014 MB perf.data (11 samples) ]

-- 
2.20.1