Ramsay Jones <ramsay@xxxxxxxxxxxxxxxxxxx> writes: > On 11/04/14 23:22, Junio C Hamano wrote: > [...] >> [New Topics] >> >> * nd/index-pack-one-fd-per-thread (2014-04-09) 1 commit >> - index-pack: work around thread-unsafe pread() >> >> Enable threaded index-pack on platforms without thread-unsafe >> pread() emulation. >> >> Will merge to 'next' and keep it there for the remainder of the cycle. > > The commit message for commit 512ebe5d ("index-pack: work around > thread-unsafe pread()", 25-03-2014) is a little misleading. OK. Can we have a concrete alternative? Multi-threaing of index-pack was disabled with c0f8654 (index-pack: Disable threading on cygwin - 2012-06-26), because pread() implementations for Cygwin and MSYS were not thread safe. Recent Cygwin does offer usable pread() and we enabled multi-threading with 103d530f (Cygwin 1.7 has thread-safe pread, 2013-07-19). Work around this problem on platforms with a thread-unsafe pread() emulation by opening one file handle per thread; it would prevent parallel pread() on different file handles from stepping on each other. Also remove NO_THREAD_SAFE_PREAD that was introduced in c0f8654 because it's no longer used anywhere. This workaround is unconditional, even for platforms with thread-safe pread() because the overhead is small (a couple file handles more) and not worth fragmenting the code. -- 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