Messages in this thread | | | Date | Sun, 08 Dec 2002 11:56:42 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH] set_cpus_allowed() for 2.4 |
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Ingo Molnar wrote: > > On Mon, 2 Dec 2002, Andrew Morton wrote: > > > I have observed two problems with the new scheduler, both serious IMO: > > > > 1) Changed sched_yield() semantics. [...] > > we noticed this OpenOffice/StarOffice problem in July, while beta-testing > RH 8.0. In July Andrea already had another yield implementation in his > tree, which was addressing an unrelated yield()-related regression. I'd > like to note here that StarOffice/OpenOffice sucked just as much under > Andrea's yield() variant as the original (and 2.5) O(1) scheduler variant > did. > > So i talked to Andrea, and we agreed in a rough solution that worked > sufficiently well for OpenOffice and the other regression as well. I > implemented it and tested it for OpenOffice. You can see (an i suspect > later incarnation) of that implementation in Andrea's current tree. My > position back then was that we should not try to move the arguably broken > 2.4 yield() implementation to 2.5. > > So this is the history of O(1) yield(). > > fortunately, things have changed since July, since due to NPTL threading > the architectural need for user-space yield() has decreased significantly > (NPTL uses futexes, no yielding anywhere), so the only worry is behavioral > compatibility with LinuxThreads (and other yield() users). I'll forward > port the new (well, old) yield() semantics to 2.5 as well, which will be > quite similar to the yield() implementation in Andrea's tree. > > there's another (this time unique) bit implemented by Andrea, a variant of > giving newly forked children priority in a more subtle way - i'm testing > this change currently, to see whether it has any positive effect on > compilation workloads. > > does this clarify things? >
Yes, thanks. Will we also be seeing the "interactivity estimator" fixes in 2.5? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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