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| author | Paul Eggert <eggert@cs.ucla.edu> | 2010-12-16 22:31:56 -0800 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2010-12-16 22:32:06 -0800 |
| commit | 8e81a99c2690a5a8e3a3449e9c4f440738e0cac9 (patch) | |
| tree | 81978ebc6cb1b584d303d5b91bdc96bce31b6172 /NEWS | |
| parent | 1b31ce6982a9151d9dfe2ea3595ad7595cb9ca86 (diff) | |
| download | coreutils-8e81a99c2690a5a8e3a3449e9c4f440738e0cac9.tar.xz | |
sort: do not generate thousands of subprocesses for 16-way merge
Without this change, tests/misc/sort-compress-hang would consume
more than 10,000 process slots on my RHEL 5.5 x86-64 server,
making it likely for other applications to fail due to lack of
process slots. With this change, the same benchmark causes 'sort'
to consume at most 19 process slots. The change also improved
wall-clock time by 2% and user+system time by 14% on that benchmark.
* NEWS: Document this.
* src/sort.c (MAX_PROCS_BEFORE_REAP): Remove.
(reap_exited): Renamed from reap_some; this is a more accurate name,
since "some" incorrectly implies that it reaps at least one process.
All uses changed.
(reap_some): New function: it *does* reap at least one process.
(pipe_fork): Do not allow more than NMERGE + 2 subprocesses.
(mergefps, sort): Omit check for exited processes: no longer needed,
and anyway the code consumed too much CPU per line when 2 < nprocs.
Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 3 |
1 files changed, 2 insertions, 1 deletions
@@ -22,7 +22,8 @@ GNU coreutils NEWS -*- outline -*- into the stack of an expired thread. [bug introduced in coreutils-8.6] sort --compress no longer mishandles subprocesses' exit statuses, - and no longer hangs indefinitely due to a bug in waiting for subprocesses. + no longer hangs indefinitely due to a bug in waiting for subprocesses, + and no longer generates many more than NMERGE subprocesses. sort -m -o f f ... f no longer dumps core when file descriptors are limited. |