Aubrey Li wrote: > On 1/25/07, Vaidyanathan Srinivasan <[EMAIL PROTECTED]> wrote: >> >> Christoph Lameter wrote: >>> On Wed, 24 Jan 2007, Vaidyanathan Srinivasan wrote: >>> >>>> With your patch, MMAP of a file that will cross the pagecache limit hangs >>>> the >>>> system. As I mentioned in my previous mail, without subtracting the >>>> NR_FILE_MAPPED, the reclaim will infinitely try and fail. >>> Well mapped pages are still pagecache pages. >>> >> Yes, but they can be classified under a process RSS pages. Whether it >> is an anon page or shared mem or mmap of pagecache, it would show up >> under RSS. Those pages can be limited by RSS limiter similar to the >> one we are discussing in pagecache limiter. In my opinion, once a >> file page is mapped by the process, then it should be treated at par >> with anon pages. Application programs generally do not mmap a file >> page if the reuse for the content is very low. >> > > I agree, we shouldn't take mmapped page into account. > But Vaidy - even with your patch, we are still using the existing > reclaimer, that means we dont ensure that only page cache is > reclaimed/limited. mapped pages will be hit also. > I think we still need to add a new scancontrol field to lock mmaped > pages and remove unmapped pagecache pages only.
I have tried to add scan control to Roy's patch at http://lkml.org/lkml/2007/01/17/96 In that patch, we search and remove only pages that are not mapped. We also remove referenced and hot pagecache pages which the normal reclaimer is not expected to consider. I will try to fit that logic in Christoph's patch and test. --Vaidy > -Aubrey > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [EMAIL PROTECTED] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
