On Fri, Aug 30, 2013 at 8:58 PM, Julian Seward <jsew...@acm.org> wrote:
> I am not sure how to deal with (4). Really it's completely unrelated > to the unwind mechanism -- it has to do with SPS' sampling policy at > the level above. There have been some ideas floated around to detect > when a thread is in a syscall by looking at the instruction at the > program counter, since the "enter the kernel" instructions are > different from all other ones. That doesn't give a way to avoid on > average half a long-interval delay of missed samples when a thread > leaves a syscall. > Being able to sample uniformly whether or not the thread is in a syscall is important sometimes, so let's not lose that. To sample only non-blocked states can't we count CPU clocks in user space, instead of the real-time clock, or something like that? Rob -- Jtehsauts tshaei dS,o n" Wohfy Mdaon yhoaus eanuttehrotraiitny eovni le atrhtohu gthot sf oirng iyvoeu rs ihnesa.r"t sS?o Whhei csha iids teoa stiheer :p atroa lsyazye,d 'mYaonu,r "sGients uapr,e tfaokreg iyvoeunr, 'm aotr atnod sgaoy ,h o'mGee.t" uTph eann dt hwea lmka'n? gBoutt uIp waanndt wyeonut thoo mken.o w * * _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
