From: Nguyen Thai Ngoc Duy Date: Mon, 12 Mar 2012 12:18:44 GMT Subject: Re: [PATCH v2 2/2] index-pack: support multithreaded delta resolving Message-ID: In-Reply-To: <87boo282hg.fsf@thomas.inf.ethz.ch> On Mon, Mar 12, 2012 at 6:47 PM, Thomas Rast wrote: > Nguyen Thai Ngoc Duy writes: > >> 2012/3/12 Thomas Rast : >>> Nguyễn Thái Ngọc Duy writes: >>> >>>> This puts delta resolving on each base on a separate thread, one base >>>> cache per thread. Per-thread data is grouped in struct thread_local. >>>> When running with nr_threads == 1, no pthreads calls are made. The >>>> system essentially runs in non-thread mode. >>> >>> As discussed when we took the git-grep measurements, it may be >>> interesting to have a way to run 1 thread.  Can you put in such an >>> option? >> >> Sorry I wasn't clear, nr_threads == 1 is equivalent to --threads=1. So >> yes it supports running in non-thread mode. > > Well, in that case I wasn't clear: I meant that there should be a way to > run with the whole threading machinery enabled, but still only have one > thread (doing the work, possibly having another that fills the queue). > > That allows us to see how big the overhead is. I really don't want to add overhead, no matter how small it is, to --threads=1. How's GIT_USE_THREADS variable for testing purposes? Threaded grep can share the same variable if you also like to avoid threading machinery in git grep --threads=1. -- Duy