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| author | Pádraig Brady <P@draigBrady.com> | 2010-12-18 05:27:46 +0000 |
|---|---|---|
| committer | Pádraig Brady <P@draigBrady.com> | 2010-12-19 00:33:45 +0000 |
| commit | 0e181024c00b746a930aab6a0cfd9162d7b67ae4 (patch) | |
| tree | 994336fac3c2c31ab31fa7b1b8700eb12c114243 /doc | |
| parent | eea8e7530bf3c469dd7f4e598c993ff7fb4574e9 (diff) | |
| download | coreutils-0e181024c00b746a930aab6a0cfd9162d7b67ae4.tar.xz | |
sort: use at most 8 threads by default
* src/sort.c (main): If --parallel isn't specified,
restrict the number of threads to 8 by default.
If the --parallel option is specified, then
allow any number of threads to be set, independent
of the number of processors on the system.
* doc/coreutils.texi (sort invocation): Document the changes
to determining the number of threads to use.
Mention the memory overhead when using multiple threads.
* tests/misc/sort-spinlock-abuse: Allow single core
systems that support pthreads.
* tests/misc/sort-stale-thread-mem: Likewise.
* tests/misc/sort-unique-segv: Likewise.
* NEWS: Mention the change in behaviour.
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/coreutils.texi | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 00a557578..a74f64599 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -4190,10 +4190,11 @@ disks and controllers. @item --parallel=@var{n} @opindex --parallel @cindex multithreaded sort -Limit the number of sorts run in parallel to @var{n}. By default, -@var{n} is set to the number of available processors, and values -greater than that are reduced to that limit. Also see -@ref{nproc invocation}. +Set the number of sorts run in parallel to @var{n}. By default, +@var{n} is set to the number of available processors, but limited +to 8, as there are diminishing performance gains after that. +Note also that using @var{n} threads increases the memory usage by +a factor of log @var{n}. Also see @ref{nproc invocation}. @item -u @itemx --unique |