Messages in this thread | | | Date | Wed, 8 Feb 2012 16:29:53 +0800 | Subject | Re: [PATCH] block: strip out locking optimization in put_io_context() | From | Shaohua Li <> |
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2012/2/8 Shaohua Li <shaohua.li@intel.com>: > 2012/2/8 Tejun Heo <tj@kernel.org>: >> Hello, >> >> On Tue, Feb 07, 2012 at 08:33:15AM -0800, Linus Torvalds wrote: >>> Yeah, please just get rid of the crazy code. Maybe *that* fixes the >>> regression too, who knows? >>> >>> For all we know, the "fast case" is what causes extra locking only to >>> then fail and not even be a fast-path. >> >> Yeah, I was about to ask Shaohua to test the version w/o optimization. >> With heavily loaded request_queue, trylock failure could be frequent, >> which I wasn't testing. >> >> Shaohua, can you please test the version w/o optimization? Also, can >> you please give a bit more details on the setup? Are there multiple >> swap devices? Is it SSD or rotating disk? > the test adds mem=4G in a 2 sockets 16 CPU machine. > just make several copy of kernel source in tmpfs (so there is swap > depending on your > memory size) and run kernel build in the kernel source in the meaning time. > there is only one swap device which is a rotating disk. > > I'll test both patches soon. Tried all the options, the regression still exists. Any new idea? I'll spend some time on it if I can get anything
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