Messages in this thread | ![/](/images/icornerl.gif) | | Date | Sun, 21 Nov 2010 20:17:29 -0500 | From | Rik van Riel <> | Subject | Re: [RFC 1/2] deactive invalidated pages |
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On 11/21/2010 09:30 AM, Minchan Kim wrote: > Recently, there are reported problem about thrashing. > (http://marc.info/?l=rsync&m=128885034930933&w=2) > It happens by backup workloads(ex, nightly rsync). > That's because the workload makes just use-once pages > and touches pages twice. It promotes the page into > active list so that it results in working set page eviction. > > Some app developer want to support POSIX_FADV_NOREUSE. > But other OSes don't support it, either. > (http://marc.info/?l=linux-mm&m=128928979512086&w=2) > > By Other approach, app developer uses POSIX_FADV_DONTNEED. > But it has a problem. If kernel meets page is writing > during invalidate_mapping_pages, it can't work. > It is very hard for application programmer to use it. > Because they always have to sync data before calling > fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could > be discardable. At last, they can't use deferred write of kernel > so that they could see performance loss. > (http://insights.oetiker.ch/linux/fadvise.html)
This looks promising...
Acked-by: Rik van Riel <riel@redhat.com>
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