Messages in this thread | | | Date | Fri, 8 May 2009 11:30:04 +0800 | From | Wu Fengguang <> | Subject | Re: [PATCH -mm] vmscan: make mapped executable pages the first class citizen |
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On Thu, May 07, 2009 at 11:17:46PM +0800, Peter Zijlstra wrote: > On Thu, 2009-05-07 at 17:10 +0200, Johannes Weiner wrote: > > > > @@ -1269,8 +1270,15 @@ static void shrink_active_list(unsigned > > > > > > /* page_referenced clears PageReferenced */ > > > if (page_mapping_inuse(page) && > > > - page_referenced(page, 0, sc->mem_cgroup)) > > > + page_referenced(page, 0, sc->mem_cgroup)) { > > > + struct address_space *mapping = page_mapping(page); > > > + > > > pgmoved++; > > > + if (mapping && test_bit(AS_EXEC, &mapping->flags)) { > > > + list_add(&page->lru, &l_active); > > > + continue; > > > + } > > > + } > > > > Since we walk the VMAs in page_referenced anyway, wouldn't it be > > better to check if one of them is executable? This would even work > > for executable anon pages. After all, there are applications that cow > > executable mappings (sbcl and other language environments that use an > > executable, run-time modified core image come to mind). > > Hmm, like provide a vm_flags mask along to page_referenced() to only > account matching vmas... seems like a sensible idea.
I'd prefer to make vm_flags an out-param, like this:
- int page_referenced(struct page *page, int is_locked, + int page_referenced(struct page *page, int is_locked, unsigned long *vm_flags, struct mem_cgroup *mem_cont)
which allows reporting more versatile flags and status bits :)
Thanks, Fengguang
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