Re: [PATCH] vmscan: bail out of page reclaim after swap_cluster_max pages

From: KOSAKI Motohiro
Date: Sun Nov 30 2008 - 01:31:15 EST


> Reclaiming is very easy when the workload is just page cache,
> because the application will be throttled when too many page
> cache pages are dirty.
>
> When using mmap or memory hogs writing to swap, applications
> will not be throttled by the "too many dirty pages" logic,
> but may instead end up being throttled in the direct reclaim
> path instead.
>
> At that point direct reclaim may become a lot more common,
> making the imbalance more significant.

fair enough.


> I'll run a few tests.

Great.
I'm looking for your mail :)


> > Andrew, I hope add this mesurement result to rvr bailing out patch description too.
>
> So far the performance numbers you have measured are very
> encouraging and do indeed suggest that the priority==DEF_PRIORITY
> thing does not make a difference.

thank you.

I believe reclaim latency reducing doesn't only improve hpc, but also
improve several multimedia and desktop application.



--
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/