Messages in this thread | | | Subject | Re: [rfc][patch] mm: madvise(WILLNEED) for anonymous memory | From | Peter Zijlstra <> | Date | Thu, 20 Dec 2007 15:56:00 +0100 |
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On Thu, 2007-12-20 at 15:47 +0100, Peter Zijlstra wrote: > On Thu, 2007-12-20 at 14:09 +0000, Hugh Dickins wrote:
> > Interesting divergence: make_pages_present faults in writable pages > > in a writable vma, whereas the file case's force_page_cache_readahead > > doesn't even insert the pages into the mm. > > Yeah, the find_vma and write fault thing are the reason I didn't use > make_pages_present. > > I had noticed the difference in pte population between > force_page_cache_readahead and make_pages_present, but it seemed to me > that writing a function to walk the page tables and populate the > swapcache but not populate the ptes wasn't worth the effort.
Ah, another, more important difference:
force_page_cache_readahead will not wait for the read to complete, whereas get_user_pages() will be fully synchronous.
I think I'd better come up with something else then,..
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