Messages in this thread | | | Date | Mon, 22 Nov 2004 15:16:28 -0800 | From | Andrew Morton <> | Subject | Re: deferred rss update instead of sloppy rss |
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Christoph Lameter <clameter@sgi.com> wrote: > > On Mon, 22 Nov 2004, Andrew Morton wrote: > > > > The page fault code only increments rss. For larger transactions that > > > increase / decrease rss significantly the page_table_lock is taken and > > > mm->rss is updated directly. So no > > > gross inaccuracies can result. > > > > Sure. Take a million successive pagefaults and mm->rss is grossly > > inaccurate. Hence my suggestion that it be spilled into mm->rss > > periodically. > > It is spilled into mm->rss periodically. That is the whole point of the > patch. > > The timer tick occurs every 1 ms.
That only works if the task happens to have the CPU when the timer tick occurs. There remains no theoretical upper bound to the error in mm->rss, and that's very easy to fix. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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