Messages in this thread | | | Date | Thu, 26 Apr 2001 11:31:06 +0200 (CEST) | From | Mike Galbraith <> | Subject | Re: [patch] swap-speedup-2.4.3-B3 (fwd) |
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On Thu, 26 Apr 2001, Ingo Molnar wrote:
> On Thu, 26 Apr 2001, Mike Galbraith wrote: > > > 2.4.4.pre7.virgin > > real 11m33.589s > > > 2.4.4.pre7.sillyness > > real 9m30.336s > > very interesting. Looks like there are still reserves in the VM, for heavy > workloads. (and swapping is all about heavy workloads.) > > it would be interesting to see why your patch has such a good effect. > (and it would be nice get the same improvement in a clean way.)
It's not good.. it's an ugly beaste from hell ;-)
> > - if (!page->age) > > - deactivate_page(page); > > + age_page_down(page); > > this one preserves the cache a bit more agressively.
(intent)
> > > /* Always start by trying to penalize the process that is allocating memory */ > > if (mm) > > - retval = swap_out_mm(mm, swap_amount(mm)); > > + return swap_out_mm(mm, swap_amount(mm)); > > keep swap-out activity more focused to the process that is generating the > VM pressure. It might make sense to test this single change in isolation. > (While we cannot ignore to swap out other contexts under memory pressure, > we could do something to make it focused on the current MM a bit more.)
(also the intent.. make 'em pagein like a bugger to slow down cache munh)
> > + static unsigned long lastscan; > > + > > + if (lastscan == jiffies) > > + return 0; > > limit the runtime of refill_inactive_scan(). This is similar to Rik's > reclaim-limit+aging-tuning patch to linux-mm yesterday. could you try > Rik's patch with your patch except this jiffies hack, does it still > achieve the same improvement?
No. It livelocked on me with almost all active pages exausted.
> > + int shortage = inactive_shortage(); > > > > + if (refill_inactive_scan(DEF_PRIORITY, 0) < shortage) > > /* If refill_inactive_scan failed, try to page stuff out.. */ > > swap_out(DEF_PRIORITY, gfp_mask); > > > > + return 0; > > (i cannot see how this chunk affects the VM, AFAICS this too makes the > zapping of the cache less agressive.)
(more folks get snagged on write.. they can't eat cache so fast)
-Mike
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