Date: Fri, 4 Mar 2011 09:13:28 +0300 From: Chagin Dmitry <dchagin@freebsd.org> To: Alexander Best <arundel@freebsd.org> Cc: freebsd-emulation@freebsd.org Subject: Re: regarding issues with futexes and multiple threads Message-ID: <20110304061328.GA4073@dchagin.static.corbina.ru> In-Reply-To: <20110303212051.GA54978@freebsd.org> References: <20110303212051.GA54978@freebsd.org>
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[-- Attachment #1 --] On Thu, Mar 03, 2011 at 09:20:51PM +0000, Alexander Best wrote: > hi there, > > i've been investigating this issue for quite a while now and simply wanted to > post some measurements i did. > > basically there's a massive slowdown when a process triggers a lot of threads > which are doing futex operations. the following example is from darren hart's > futex test suite (performance/). the slowdown seems to SMP related. here are > the measurements running with SMP enabled and with kern.smp.disabled=1: > 1) slowdown is expected behaviour. 2) is it possible to run this test suite on FreeBSD? -- chd, Have fun! [-- Attachment #2 --] -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (FreeBSD) iEYEARECAAYFAk1wgwgACgkQ0t2Tb3OO/O0GbQCcCCzoPqzOYU4SG6YKSdYBWtHm BdUAoNCntqOHa/+Ml80jUdMK/DflZyDV =5Nn3 -----END PGP SIGNATURE-----
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