From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: <20080304225228.035563249@redhat.com> References: <20080304225157.573336066@redhat.com> Date: Tue, 04 Mar 2008 17:52:17 -0500 From: Rik van Riel Subject: [patch 20/20] cull non-reclaimable anon pages from the LRU at fault time Content-Disposition: inline; filename=noreclaim-07-cull-nonreclaimable-anon-pages-in-fault-path.patch Sender: owner-linux-mm@kvack.org Return-Path: To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, KOSAKI Motohiro , Lee Schermerhorn , Lee Schermerhorn List-ID: V2 -> V3: + rebase to 23-mm1 atop RvR's split lru series. V1 -> V2: + no changes Optional part of "noreclaim infrastructure" In the fault paths that install new anonymous pages, check whether the page is reclaimable or not using lru_cache_add_active_or_noreclaim(). If the page is reclaimable, just add it to the active lru list [via the pagevec cache], else add it to the noreclaim list. This "proactive" culling in the fault path mimics the handling of mlocked pages in Nick Piggin's series to keep mlocked pages off the lru lists. Notes: 1) This patch is optional--e.g., if one is concerned about the additional test in the fault path. We can defer the moving of nonreclaimable pages until when vmscan [shrink_*_list()] encounters them. Vmscan will only need to handle such pages once. 2) I moved the call to page_add_new_anon_rmap() to before the test for page_reclaimable() and thus before the calls to lru_cache_add_{active|noreclaim}(), so that page_reclaimable() could recognize the page as anon. TBD: I think this reordering is OK, but the previous order may have existed to close some obscure race? 3) The 'vma' argument to page_reclaimable() is require to notice that we're faulting a page into an mlock()ed vma w/o having to scan the page's rmap in the fault path. Culling mlock()ed anon pages is currently the only reason for this patch. Signed-off-by: Lee Schermerhorn Signed-off-by: Rik van Riel Index: linux-2.6.25-rc3-mm1/mm/memory.c =================================================================== --- linux-2.6.25-rc3-mm1.orig/mm/memory.c 2008-03-04 15:30:20.000000000 -0500 +++ linux-2.6.25-rc3-mm1/mm/memory.c 2008-03-04 16:22:58.000000000 -0500 @@ -1678,7 +1678,7 @@ gotten: set_pte_at(mm, address, page_table, entry); update_mmu_cache(vma, address, entry); SetPageSwapBacked(new_page); - lru_cache_add_active_anon(new_page); + lru_cache_add_active_or_noreclaim(new_page, vma); page_add_new_anon_rmap(new_page, vma, address); /* Free the old page.. */ @@ -2147,7 +2147,7 @@ static int do_anonymous_page(struct mm_s goto release; inc_mm_counter(mm, anon_rss); SetPageSwapBacked(page); - lru_cache_add_active_anon(page); + lru_cache_add_active_or_noreclaim(page, vma); page_add_new_anon_rmap(page, vma, address); set_pte_at(mm, address, page_table, entry); @@ -2289,10 +2289,10 @@ static int __do_fault(struct mm_struct * entry = maybe_mkwrite(pte_mkdirty(entry), vma); set_pte_at(mm, address, page_table, entry); if (anon) { - inc_mm_counter(mm, anon_rss); + inc_mm_counter(mm, anon_rss); SetPageSwapBacked(page); - lru_cache_add_active_anon(page); - page_add_new_anon_rmap(page, vma, address); + lru_cache_add_active_or_noreclaim(page, vma); + page_add_new_anon_rmap(page, vma, address); } else { inc_mm_counter(mm, file_rss); page_add_file_rmap(page); Index: linux-2.6.25-rc3-mm1/mm/swap_state.c =================================================================== --- linux-2.6.25-rc3-mm1.orig/mm/swap_state.c 2008-03-04 15:46:42.000000000 -0500 +++ linux-2.6.25-rc3-mm1/mm/swap_state.c 2008-03-04 16:22:58.000000000 -0500 @@ -300,7 +300,10 @@ struct page *read_swap_cache_async(swp_e /* * Initiate read into locked page and return. */ - lru_cache_add_anon(new_page); + if (!page_reclaimable(new_page, vma)) + lru_cache_add_noreclaim(new_page); + else + lru_cache_add_anon(new_page); swap_readpage(NULL, new_page); return new_page; } -- All Rights Reversed -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org