-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 According to Bob Proulx on 9/5/2005 3:33 PM: > If it is not too much trouble could you do post some simple benchmarks > showing that larger buffer sizes are significantly better than the 32k > buffer sizes? If so then it would help to promote your case.
Chris Faylor (one of the cygwin maintainers) proposed a benchmark that times the entire operation, not just the xargs invocation: http://sources.redhat.com/ml/cygwin-patches/2005-q3/msg00107.html His numbers, with a modified xargs that ignored the _SC_ARG_MAX limit, showed improvement for cygwin processes (which can cope with the larger limits) as -s increased beyond 32k. > > It just very quickly does not matter. Let me guess, without data and > perhaps wrongly, that this will not be a big performance difference on > cygwin either. So probably on cygwin I would go ahead and make that > size restriction so that it works correctly all of the time. But I am > not mothering over that platform and I know that those that do will > want to do better so personally I sympathize. But it just does not > seem to me like a performance lever. Forking on cygwin is very expensive. I guess what I will end up doing is maintaining a cygwin-local patch that defaults to 32k+envsize (instead of the standard 128k+envsize) so that the default of not using -s always works on non-cygwin programs which have the 32k limit, but letting -s be ruled by sysconf(_SC_ARG_MAX), which Chris Faylor wants to leave at 1 meg (or even increase, because he has instead proposed a fix for the upcoming cygwin 1.5.19 where ALL cygwin processes use the under-the-hood argument passing mechanism that allow them to exceed the Windows limitation, limited only by malloc, rather than the current 1.5.18 behavior of just the cygexec mount points getting the increased limit). Yes, it means that xargs will get E2BIG if someone uses -s on a non-cygwin program, even though the POSIX rules are in place to try to prevent that, but it fits with cygwin's philosophy of favoring Unix emulation over native Windows apps, and at least the default will work everywhere. - -- Life is short - so eat dessert first! Eric Blake [EMAIL PROTECTED] volunteer cygwin package maintainer for findutils -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (Cygwin) Comment: Public key at home.comcast.net/~ericblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFDMVyb84KuGfSFAYARAsbtAJ42HNzQ1eQjU41ohztVbyE2B+hsvgCdFBBd W8o+68ICWU+fzA1y+KSXK1I= =5rnV -----END PGP SIGNATURE----- _______________________________________________ Bug-findutils mailing list [email protected] http://lists.gnu.org/mailman/listinfo/bug-findutils
