On Fri, Feb 12, 2016 at 8:39 AM, Kyle Huey <m...@kylehuey.com> wrote:
> On Thu, Feb 11, 2016 at 11:35 AM, Robert O'Callahan <rob...@ocallahan.org> > wrote: > >> On Thu, Feb 11, 2016 at 11:55 PM, Nicolas B. Pierron < >> nicolas.b.pier...@mozilla.com> wrote: >> >> > On 02/10/2016 08:04 PM, Robert O'Callahan wrote: >> > >> >> Background: >> >> http://robert.ocallahan.org/2016/02/introducing-rr-chaos-mode.html >> >> >> >> I just landed on rr master support for a "-h" option which enables a >> chaos >> >> mode for rr recording. This is designed to help reproduce intermittent >> >> test >> >> failures under rr. […] >> >> >> > >> > Thanks Roc, I will give it a try. >> > >> > On the other hand, I used to rely more on the "-c" option to achieve a >> > similar thing in the past, instead of the "-e" option. >> > >> > The reason I did so being that the thread I am interested in does a few >> > syscalls compared to the rest of the program. Thus I felt that using >> "-e" >> > option would give it an unfair large time slices compared to what is >> > supposed to happen if the threads are running concurrently. >> >> >> The -e option is gone now because the new scheduler (with or without chaos >> mode) does not take system calls into account when calculating the length >> of a timeslice. We only count conditional branches. >> > > So we context switch at a syscall now only when the current thread happens > to become unschedulable? > Or if any higher-priority thread has become runnable. This includes not just a low-priority thread doing a FUTEX_WAKE to wake a high-priority thread, but also a thread changing its priority or another thread's priority, or even a low-priority thread writing to a pipe that a high-priority thread is reading from. (Though in the latter case the scheduler *might* not see the high-priority thread become runnable in time in all cases.) Rob -- lbir ye,ea yer.tnietoehr rdn rdsme,anea lurpr edna e hnysnenh hhe uresyf toD selthor stor edna siewaoeodm or v sstvr esBa kbvted,t rdsme,aoreseoouoto o l euetiuruewFa kbn e hnystoivateweh uresyf tulsa rehr rdm or rnea lurpr .a war hsrer holsa rodvted,t nenh hneireseoouot.tniesiewaoeivatewt sstvr esn _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
