On 08/05/2014 10:13 PM, H. Peter Anvin wrote: > On 08/05/2014 07:52 AM, Denys Vlasenko wrote: >> Version 3 of the patchset. >> >> Please consider applying at least two first patches, they are definitely >> safe, >> and the second one fixes a latent bug. >> > > Please do provide latency measurements. I highly suspect that they will > turn out that that this has no significant impact on latency, but we > need to know for sure.
I ran tests in totally quiescent state (booted in /bin/sh) on dual Core i7: vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) i7-2620M CPU @ 2.70GHz stepping : 7 microcode : 0x29 "timing_test32 20 getpid" command, best time: old kernel 266.88 ns per getpid syscall new kernel 265.95 ns per getpid syscall "timing_test64 20 getpid" command, best time: old kernel 54.12 ns per getpid syscall new kernel 54.30 ns per getpid syscall In both cases, run-to-run test variability is about 2 ns. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
