Messages in this thread | | | Date | Fri, 6 Feb 2009 19:06:34 +0900 | Subject | Re: [PATCH 3/3][RFC] swsusp: shrink file cache first | From | MinChan Kim <> |
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On Fri, Feb 6, 2009 at 5:03 PM, MinChan Kim <minchan.kim@gmail.com> wrote: > Hi, Johannes. > I have some questions. > Just out of curiosity. :) > > On Fri, Feb 06, 2009 at 04:11:28AM +0100, Johannes Weiner wrote: >> File cache pages are saved to disk either through normal writeback by >> reclaim or by including them in the suspend image written to a >> swapfile. >> >> Writing them either way should take the same amount of time but doing >> normal writeback and unmap changes the fault behaviour on resume from >> prefault to on-demand paging, smoothening out resume and giving > > What do you mean "unmap"? > Why normal writeback and unmap chnages the fault behavior on resume ?
Please, Ignore poor first my question. :( I agree with your opinion.
>> previously cached pages the chance to stay out of memory completely if >> they are not used anymore. >> >> Another reason for preferring file page eviction is that the locality >> principle is visible in fault patterns and swap might perform really >> bad with subsequent faulting of contiguously mapped pages. > > Why do you think that swap might perform bad with subsequent faulting > of contiguusly mapped page ? > You mean normal file system is faster than swap due to readahead and > smart block of allocation ?
But, I still can't understand this issue. what mean "page eviction" ? Is it reclaim or swap out ?
> > -- > Kinds Regards > MinChan Kim > >
-- Kinds regards, MinChan Kim
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