Re: [ck] Re: Preempt Threshold Measurements

From: Gabriel Devenyi
Date: Mon Jul 12 2004 - 22:10:58 EST


Ah good, thanks for the suggestion on how to improve this... Now, what exactly
is that, and where/how do I change it.... (I really should start/finish that
"understanding the linux kernel" book of mine)


--
Gabriel Devenyi
devenyga@xxxxxxxxxxx

On Monday 12 July 2004 22:55, William Lee Irwin III wrote:
> On Mon, Jul 12, 2004 at 10:48:50PM -0400, Gabriel Devenyi wrote:
> > Well I'm not particularly educated in kernel internals yet, here's some
> > reports from the system when its running.
> > 6ms non-preemptible critical section violated 4 ms preempt threshold
> > starting at do_munmap+0xd2/0x140 and ending at do_munmap+0xeb/0x140
> > [<c014007b>] do_munmap+0xeb/0x140
> > [<c01163b0>] dec_preempt_count+0x110/0x120
> > [<c014007b>] do_munmap+0xeb/0x140
> > [<c014010f>] sys_munmap+0x3f/0x60
> > [<c0103ee1>] sysenter_past_esp+0x52/0x71
>
> Looks like ZAP_BLOCK_SIZE may be too large for you. Lowering that some
> may "help" this. It's probably harmless, but try lowering that to half
> of whatever it is now, or maybe 64*PAGE_SIZE. It may be worthwhile
> to restructure how the preemption points are done in unmap_vmas() so
> we don't end up in some kind of tuning nightmare.
>
>
> -- wli
> _______________________________________________
> ck@xxxxxxxxxxxxxxx
> ck mailing list - unmoderated. Please reply-to-all when posting.
> http://bhhdoa.org.au/mailman/listinfo/ck
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/