[PATCH (block.git) 0/2] IO CPU affinity update:

Alan D. Brunelle
2008-03-17T16:34:37Z

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.

Alan