rene.scharfe@xxxxxxxxxxxxxx wrote on Wed, 07 Dec 2011 18:00 +0100: > Am 07.12.2011 09:12, schrieb Thomas Rast: > > René Scharfe wrote: > >> diff --git a/Documentation/git-grep.txt b/Documentation/git-grep.txt > >> index 47ac188..e981a9b 100644 > >> --- a/Documentation/git-grep.txt > >> +++ b/Documentation/git-grep.txt > >> @@ -228,8 +228,9 @@ OPTIONS > >> there is a match and with non-zero status when there isn't. > >> > >> --threads <n>:: > >> + Run <n> search threads in parallel. Default is 8 when searching > >> + the worktree and 0 otherwise. This option is ignored if git was > >> + built without support for POSIX threads. > > [...] > >> - nr_threads = (online_cpus() > 1) ? THREADS : 0; > >> + nr_threads = (online_cpus() > 1 && !list.nr) ? THREADS : 0; > > > > It would be more consistent to stick to the pack.threads convention > > where 0 means "all of my cores", so to disable threading the user > > would set the number of threads to 1. Or were you trying to measure > > the contention between the worker thread and the add_work() thread? > > Yes, indeed, the cost for the threading overhead does interest me. The > documentation should perhaps mention --no-threads explicitly to avoid > confusion. > > Currently there is no way to specify "as many threads as there are > cores" here. Previous measurements indicated that it wasn't too useful, > however, because I/O parallelism was beneficial even for machines with > less than eight cores and more threads didn't pay off. Right. Even for single CPU machines this is true, so the nr_threads calculation above should still use all 8 THREADS regardless of the number of online_cpus(). -- Pete -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html