Messages in this thread |  | | | Date | Thu, 11 Aug 2011 13:31:13 -0700 | | Subject | Re: [PATCH v6 2/2] Output stall data in debugfs | | From | Alex Neronskiy <> |
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On Thu, Aug 11, 2011 at 1:23 PM, Peter Zijlstra <peterz@infradead.org> wrote: > On Thu, 2011-08-11 at 13:10 -0700, Alex Neronskiy wrote: > Ah, right, yeah, stick another lock in there.. One does worry about the > whole writer concurrency thing though, isn't it likely all cpus will > tickle the thing in quick succession? Putting a global lock in that path > isn't good,.. always think of the poor sod with the 4096 cpu machine. Is it common to disable interrupts on all 4096 CPU's at once?
> Also, is all of this really useful? The hardlockup watchdog is useful > when you mess up bad, but other than that I've never found it to be > useful at all. > > I mean, we're at the point where a PREEMPT=y kernel has a pretty decent > latency and the PREEMPT_RT kernels live at ~30us. So wth are you > measuring? Well, not all kernels have PREEMPT. Chromebook kernels don't, for example.
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