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| author | Wladimir J. van der Laan <laanwj@gmail.com> | 2015-07-01 17:38:15 +0200 |
|---|---|---|
| committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2015-07-01 18:01:16 +0200 |
| commit | 47162673c79c757a9c038c4ddc41fb3022223bde (patch) | |
| tree | eb472ad23b918630102983ba5ca776e8bb3c7016 /src/init.cpp | |
| parent | da77a6f7611f71443914e1c71df1e52468cf507d (diff) | |
| download | bitcoin-47162673c79c757a9c038c4ddc41fb3022223bde.tar.xz | |
Use real number of cores for default -par, ignore virtual cores
To determine the default for `-par`, the number of script verification
threads, use [boost::thread::physical_concurrency()](http://www.boost.org/doc/libs/1_58_0/doc/html/thread/thread_management.html#thread.thread_management.thread.physical_concurrency)
which counts only physical cores, not virtual cores.
Virtual cores are roughly a set of cached registers to avoid context
switches while threading, they cannot actually perform work, so spawning
a verification thread for them could even reduce efficiency and will put
undue load on the system.
Should fix issue #6358, as well as some other reported system overload
issues, especially on Intel processors.
The function was only introduced in boost 1.56, so provide a utility
function `GetNumCores` to fall back for older Boost versions.
Diffstat (limited to 'src/init.cpp')
| -rw-r--r-- | src/init.cpp | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/init.cpp b/src/init.cpp index c4e3573de3..de239df6b8 100644 --- a/src/init.cpp +++ b/src/init.cpp @@ -283,7 +283,7 @@ std::string HelpMessage(HelpMessageMode mode) strUsage += HelpMessageOpt("-loadblock=<file>", _("Imports blocks from external blk000??.dat file") + " " + _("on startup")); strUsage += HelpMessageOpt("-maxorphantx=<n>", strprintf(_("Keep at most <n> unconnectable transactions in memory (default: %u)"), DEFAULT_MAX_ORPHAN_TRANSACTIONS)); strUsage += HelpMessageOpt("-par=<n>", strprintf(_("Set the number of script verification threads (%u to %d, 0 = auto, <0 = leave that many cores free, default: %d)"), - -(int)boost::thread::hardware_concurrency(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS)); + -GetNumCores(), MAX_SCRIPTCHECK_THREADS, DEFAULT_SCRIPTCHECK_THREADS)); #ifndef WIN32 strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), "bitcoind.pid")); #endif @@ -774,7 +774,7 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler) // -par=0 means autodetect, but nScriptCheckThreads==0 means no concurrency nScriptCheckThreads = GetArg("-par", DEFAULT_SCRIPTCHECK_THREADS); if (nScriptCheckThreads <= 0) - nScriptCheckThreads += boost::thread::hardware_concurrency(); + nScriptCheckThreads += GetNumCores(); if (nScriptCheckThreads <= 1) nScriptCheckThreads = 0; else if (nScriptCheckThreads > MAX_SCRIPTCHECK_THREADS) |