Messages in this thread | | | Date | Thu, 27 Jul 2006 15:44:53 +0100 | From | Andy Whitcroft <> | Subject | Re: [PATCH] mm: use-once cleanup |
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Martin J. Bligh wrote: > >>> Peter Zijlstra wrote: >>> >>>> Hi, >>>> >>>> This is yet another implementation of the PG_useonce cleanup spoken of >>>> during the VM summit. >>>> >>> After getting bitten by rsync yet again, I guess it's time to insist >>> that this patch gets merged... >>> >>> Andrew, could you merge this? Pretty please? ;) >>> >>> >> >> Guys, this is a performance patch, right? >> >> One which has no published performance testing results, right? >> >> It would be somewhat odd to merge it under these circumstances. >> >> And this applies to all of these >> hey-this-is-cool-but-i-didnt-bother-testing-it MM patches which people >> are >> throwing around. This stuff is *hard*. It has a bad tendency to cause >> nasty problems which only become known months after the code is merged. >> >> I shouldn't have to describe all this, but >> >> - Identify the workloads which it's supposed to improve, set up tests, >> run tests, publish results. >> >> - Identify the workloads which it's expected to damage, set up tests, run >> tests, publish results. >> >> - Identify workloads which aren't expected to be impacted, make a good >> effort at demonstrating that they are not impacted. >> >> - Perform stability/stress testing, publish results. >> >> Writing the code is about 5% of the effort for this sort of thing. >> >> Yes, we can toss it in the tree and see what happens. But it tends to be >> the case that unless someone does targetted testing such as the above, >> regressions simply aren't noticed for long periods of time. <wonders >> which >> schmuck gets to do the legwork when people report problems> >> >> Just the (unchangelogged) changes to the >> when-to-call-mark_page_accessed() >> logic are a big deal. Probably these should be a separate patch - >> separately changelogged, separately tested, separately justified. >> >> Performance testing is *everything* for this sort of patch and afaict >> none >> has been done, so it's as if it hadn't been written, no? >> - >> >> >> > Rik / Peter ... I lost the original mail + patch, but if you put it > up on a URL somewhere, Andy would probably run it through the test > harness for at least some basic perf testing, if you ask him ;-) > Probably against mainline, not -mm, as -mm seems to have other > problems right now.
I'll happily run it through the test suites once I get my machines working again after 2.6.18-rc2-mm1 has finished with them :(.
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