On 07/13/2015 11:11 AM, Michael Ellerman wrote: > On Mon, 2015-07-13 at 10:54 +0530, Anshuman Khandual wrote: >> On 07/10/2015 12:40 PM, Michael Neuling wrote: >>> What's the performance impact of this? If you run this test with --fp, >>> --altivec or --vector what is the impact of adding this patch? >>> >>> http://ozlabs.org/~anton/junkcode/context_switch2.c >>> >>> eg >>> ./context_switch2 --fp 0 0 >> >> Please find the results here which looks similar with or without >> the patch being applied. > > No they don't look similar with or without. > >> (A) Floating point context switches (context_switch2 --fp 0 0) > > If you just sort them you see: > > 316478 after > 316540 after > 316650 after > 318448 after > 318904 before > 320216 before > 321206 before > 321308 before > 323460 after > 324596 before > > > It looks like ~1% degradation. Please run the test more times (maybe 1000) and > see how the numbers look.
Average of 1000 iterations looks better. With the patch : 322599.57 (Average of 1000 results) Without the patch : 320464.924 (Average of 1000 results) _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
