Messages in this thread | | | Date | Mon, 17 Mar 2008 16:57:35 -0400 | From | "Alan D. Brunelle" <> | Subject | Re: [PATCH (block.git) 0/2] IO CPU affinity update: |
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Jens Axboe wrote: > On Mon, Mar 17 2008, Alan D. Brunelle wrote: >> Hi Jens - >> >> Two patches: >> >> 1. Adds in the IRQ saving to generic_smp_call_function_single_interrupt (as you had suggested). >> 2. Ensures a single IPI generated to get a remote function call handler going. >> >> So far it is working better than before on the 4-way IA64 w/ the mkfs/untar/make test suite - after 22 runs: >> >> Part RQ MIN AVG MAX Dev >> ----- -- ------ ------ ------ ------ >> mkfs 0 18.786 19.253 19.655 0.241 >> mkfs 1 18.639 19.182 19.786 0.293 >> >> untar 0 17.140 17.486 18.250 0.322 >> untar 1 16.951 17.494 18.274 0.350 >> >> make 0 22.927 24.310 34.339 2.287 >> make 1 22.863 23.788 24.189 0.333 >> >> comb 0 59.478 61.049 70.320 2.142 >> comb 1 59.875 60.463 61.305 0.458 >> >> psys 0 3.96% 4.14% 4.39% 0.100 >> psys 1 3.60% 3.85% 4.19% 0.176 >> >> So we're seeing reduced time (~1.0%) and reduced %sys to do it (7.0%). >> The tighter deviations for make with rq=1 may be interesting... :-) >> >> I've compiled & booted the patches for x86_64 - rq=1 is working on >> that platform too. > > This is starting to look pretty good! Thanks a lot for these results, > and the ->activated optimizations. I had a feeling the unstable results > were something like this, missing ipi's. >
Jens: FYI: I am still seeing infrequent hangs on the x86_64-based platform. It happened again today after my patch was added, I did get <alt><sysrq><W> to work this time, and the threads that were stuck were waiting for IOs to complete. I believe at some point you were thinking of hacking in a block IO dump magic key as well - is that there yet?
I'll get to the ia64 testing tomorrow - have to run now, spent most of the day looking at what could cause stuff to be missed on x86_64. The code looks solid to me, but this hang needs to be figured out.
Lastly, I did do a run on a 16-way ia64 (with my patches) and again it ran fine.
Alan
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