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SubjectRe: [PATCH v3 1/3] deactivate invalidated pages
> Recently, there are reported problem about thrashing.
> (
> 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.
> (
> By other approach, app developers use 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.
> (
> In fact, invalidation is very big hint to reclaimer.
> It means we don't use the page any more. So let's move
> the writing page into inactive list's head.
> Why I need the page to head, Dirty/Writeback page would be flushed
> sooner or later. It can prevent writeout of pageout which is less
> effective than flusher's writeout.
> Originally, I reused lru_demote of Peter with some change so added
> his Signed-off-by.
> Reported-by: Ben Gamari <>
> Signed-off-by: Minchan Kim <>
> Signed-off-by: Peter Zijlstra <>
> Acked-by: Rik van Riel <>
> Cc: Wu Fengguang <>
> Cc: KOSAKI Motohiro <>
> Cc: Johannes Weiner <>
> Cc: Nick Piggin <>
> Cc: Mel Gorman <>

Reviewed-by: KOSAKI Motohiro <>

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