Messages in this thread | | | Date | Mon, 22 Nov 2004 14:13:06 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: deferred rss update instead of sloppy rss |
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On Mon, 22 Nov 2004, Andrew Morton wrote:
> hrm. I cannot see anywhere in this patch where you update task_struct.rss.
This is just the piece around it dealing with rss. The updating of rss happens in the generic code. The change to that is trivial. I can repost the whole shebang if you want.
> > + /* only holding mmap_sem here maybe get page_table_lock too? */ > > + mm->rss += tsk->rss; > > + tsk->rss = 0; > > up_read(&mm->mmap_sem); > > mmap_sem needs to be held for writing, surely?
If there are no page faults occurring anymore then we would not need to get the lock. Q: Is it safe to assume that no faults occur anymore at this point?
> just to prevent transient gross inaccuracies. For some value of "16".
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. - 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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