src/CpuAffinitySet.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 54    Interprocess Communication
   5  *
   6  */
   7
   8 #include "squid.h"
   9 #include "base/TextException.h"
  10 #include "CpuAffinitySet.h"
  11 #include "Debug.h"
  12 #include "util.h"
  13
  14 #if HAVE_ERRNO_H
  15 #include <errno.h>
  16 #endif
  17 #if HAVE_STRING_H
  18 #include <string.h>
  19 #endif
  20
  21 CpuAffinitySet::CpuAffinitySet()
  22 {
  23     CPU_ZERO(&theCpuSet);
  24     CPU_ZERO(&theOrigCpuSet);
  25 }
  26
  27 void
  28 CpuAffinitySet::apply()
  29 {
  30     Must(CPU_COUNT(&theCpuSet) > 0); // CPU affinity mask set
  31     Must(!applied());
  32
  33     bool success = false;
  34     if (sched_getaffinity(0, sizeof(theOrigCpuSet), &theOrigCpuSet)) {
  35         debugs(54, DBG_IMPORTANT, "ERROR: failed to get CPU affinity for "
  36                "process PID " << getpid() << ", ignoring CPU affinity for "
  37                "this process: " << xstrerror());
  38     } else {
  39         cpu_set_t cpuSet;
  40         memcpy(&cpuSet, &theCpuSet, sizeof(cpuSet));
  41         (void) CPU_AND(&cpuSet, &cpuSet, &theOrigCpuSet);
  42         if (CPU_COUNT(&cpuSet) <= 0) {
  43             debugs(54, DBG_IMPORTANT, "ERROR: invalid CPU affinity for process "
  44                    "PID " << getpid() << ", may be caused by an invalid core in "
  45                    "'cpu_affinity_map' or by external affinity restrictions");
  46         } else if (sched_setaffinity(0, sizeof(cpuSet), &cpuSet)) {
  47             debugs(54, DBG_IMPORTANT, "ERROR: failed to set CPU affinity for "
  48                    "process PID " << getpid() << ": " << xstrerror());
  49         } else
  50             success = true;
  51     }
  52     if (!success)
  53         CPU_ZERO(&theOrigCpuSet);
  54 }
  55
  56 void
  57 CpuAffinitySet::undo()
  58 {
  59     if (applied()) {
  60         if (sched_setaffinity(0, sizeof(theOrigCpuSet), &theOrigCpuSet)) {
  61             debugs(54, DBG_IMPORTANT, "ERROR: failed to restore original CPU "
  62                    "affinity for process PID " << getpid() << ": " <<
  63                    xstrerror());
  64         }
  65         CPU_ZERO(&theOrigCpuSet);
  66     }
  67 }
  68
  69 bool
  70 CpuAffinitySet::applied() const
  71 {
  72     return (CPU_COUNT(&theOrigCpuSet) > 0);
  73 }
  74
  75 void
  76 CpuAffinitySet::set(const cpu_set_t &aCpuSet)
  77 {
  78     memcpy(&theCpuSet, &aCpuSet, sizeof(theCpuSet));
  79 }