tools/squashfs4/patches/003-Only-use-available-CPUs.patch

   1 From bc8e655a420d2f62bb0597947e96dce7b4d3fb36 Mon Sep 17 00:00:00 2001
   2 From: Wessel Dankers <wsl@fruit.je>
   3 Date: Sun, 30 Oct 2022 19:29:28 +0100
   4 Subject: [PATCH] Only use available CPUs
   5
   6 Not all online CPUs may be available for the current process,
   7 especially when CPU affinity is involved. In such cases too many
   8 threads will be created, which will then compete unnecessarily
   9 for CPU time.
  10
  11 Use sched_getaffinity() to determine the correct number of threads
  12 to create.
  13 ---
  14  squashfs-tools/mksquashfs.c | 16 ++++++++++++----
  15  squashfs-tools/unsquashfs.c | 13 ++++++++++---
  16  2 files changed, 22 insertions(+), 7 deletions(-)
  17
  18 --- a/squashfs-tools/mksquashfs.c
  19 +++ b/squashfs-tools/mksquashfs.c
  20 @@ -52,7 +52,9 @@
  21  #include <ctype.h>
  22  #include <sys/sysinfo.h>
  23
  24 -#ifndef linux
  25 +#ifdef linux
  26 +#include <sched.h>
  27 +#else
  28  #include <sys/sysctl.h>
  29  #endif
  30
  31 @@ -5079,7 +5081,15 @@ static void initialise_threads(int readq
  32                 BAD_ERROR("Failed to set signal mask in intialise_threads\n");
  33
  34         if(processors == -1) {
  35 -#ifndef linux
  36 +#ifdef linux
  37 +               cpu_set_t cpu_set;
  38 +               CPU_ZERO(&cpu_set);
  39 +
  40 +               if(sched_getaffinity(0, sizeof cpu_set, &cpu_set) == -1)
  41 +                       processors = sysconf(_SC_NPROCESSORS_ONLN);
  42 +               else
  43 +                       processors = CPU_COUNT(&cpu_set);
  44 +#else
  45                 int mib[2];
  46                 size_t len = sizeof(processors);
  47
  48 @@ -5096,8 +5106,6 @@ static void initialise_threads(int readq
  49                         ERROR_EXIT("  Defaulting to 1\n");
  50                         processors = 1;
  51                 }
  52 -#else
  53 -               processors = sysconf(_SC_NPROCESSORS_ONLN);
  54  #endif
  55         }
  56
  57 --- a/squashfs-tools/unsquashfs.c
  58 +++ b/squashfs-tools/unsquashfs.c
  59 @@ -33,6 +33,7 @@
  60  #include "fnmatch_compat.h"
  61
  62  #ifdef __linux__
  63 +#include <sched.h>
  64  #include <sys/sysinfo.h>
  65  #include <sys/sysmacros.h>
  66  #elif defined __FreeBSD__
  67 @@ -2719,7 +2720,15 @@ void initialise_threads(int fragment_buf
  68         }
  69
  70         if(processors == -1) {
  71 -#ifndef linux
  72 +#ifdef linux
  73 +               cpu_set_t cpu_set;
  74 +               CPU_ZERO(&cpu_set);
  75 +
  76 +               if(sched_getaffinity(0, sizeof cpu_set, &cpu_set) == -1)
  77 +                       processors = sysconf(_SC_NPROCESSORS_ONLN);
  78 +               else
  79 +                       processors = CPU_COUNT(&cpu_set);
  80 +#else
  81                 int mib[2];
  82                 size_t len = sizeof(processors);
  83
  84 @@ -2735,8 +2744,6 @@ void initialise_threads(int fragment_buf
  85                                 "Defaulting to 1\n");
  86                         processors = 1;
  87                 }
  88 -#else
  89 -               processors = sysconf(_SC_NPROCESSORS_ONLN);
  90  #endif
  91         }
  92