Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759513AbYABX0B (ORCPT ); Wed, 2 Jan 2008 18:26:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758047AbYABXWg (ORCPT ); Wed, 2 Jan 2008 18:22:36 -0500 Received: from mx1.redhat.com ([66.187.233.31]:49866 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755006AbYABXWR (ORCPT ); Wed, 2 Jan 2008 18:22:17 -0500 Message-Id: <20080102224154.604131885@redhat.com> References: <20080102224144.885671949@redhat.com> User-Agent: quilt/0.46-1 Date: Wed, 02 Jan 2008 17:41:54 -0500 From: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, lee.schermerhorn@hp.com Subject: [patch 10/19] No Reclaim LRU Infrastructure Content-Disposition: inline; filename=noreclaim-01.1-no-reclaim-infrastructure.patch To: unlisted-recipients:; (no To-header on input) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 26993 Lines: 779 V1 -> V3: + rebase to 23-mm1 atop RvR's split LRU series + define NR_NORECLAIM and LRU_NORECLAIM to avoid errors when not configured. V1 -> V2: + handle review comments -- various typos and errors. + extract "putback_all_noreclaim_pages()" into a separate patch and rework as "scan_all_zones_noreclaim_pages(). Infrastructure to manage pages excluded from reclaim--i.e., hidden from vmscan. Based on a patch by Larry Woodman of Red Hat. Reworked to maintain "nonreclaimable" pages on a separate per-zone LRU list, to "hide" them from vmscan. A separate noreclaim pagevec is provided for shrink_active_list() to move nonreclaimable pages to the noreclaim list without over burdening the zone lru_lock. Pages on the noreclaim list have both PG_noreclaim and PG_lru set. Thus, PG_noreclaim is analogous to and mutually exclusive with PG_active--it specifies which LRU list the page is on. The noreclaim infrastructure is enabled by a new mm Kconfig option [CONFIG_]NORECLAIM. A new function 'page_reclaimable(page, vma)' in vmscan.c tests whether or not a page is reclaimable. Subsequent patches will add the various !reclaimable tests. We'll want to keep these tests light-weight for use in shrink_active_list() and, possibly, the fault path. Notes: 1. for now, use bit 30 in page flags. This restricts the no reclaim infrastructure to 64-bit systems. [The mlock patch, later in this series, uses another of these 64-bit-system-only flags.] Rationale: 32-bit systems have no free page flags and are less likely to have the large amounts of memory that exhibit the problems this series attempts to solve. [I'm sure someone will disabuse me of this notion.] Thus, NORECLAIM currently depends on [CONFIG_]64BIT. 2. The pagevec to move pages to the noreclaim list results in another loop at the end of shrink_active_list(). If we ultimately adopt Rik van Riel's split lru approach, I think we'll need to find a way to factor all of these loops into some common code. 3. TODO: Memory Controllers maintain separate active and inactive lists. Need to consider whether they should also maintain a noreclaim list. Also, convert to use Christoph's array of indexed lru variables? See //TODO note in mm/memcontrol.c re: isolating non-reclaimable pages. 4. TODO: more factoring of lru list handling. But, I want to get this as close to functionally correct as possible before introducing those perturbations. Signed-off-by: Lee Schermerhorn Index: linux-2.6.24-rc6-mm1/mm/Kconfig =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/Kconfig 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/Kconfig 2008-01-02 16:00:54.000000000 -0500 @@ -193,3 +193,13 @@ config NR_QUICK config VIRT_TO_BUS def_bool y depends on !ARCH_NO_VIRT_TO_BUS + +config NORECLAIM + bool "Track non-reclaimable pages (EXPERIMENTAL; 64BIT only)" + depends on EXPERIMENTAL && 64BIT + help + Supports tracking of non-reclaimable pages off the [in]active lists + to avoid excessive reclaim overhead on large memory systems. Pages + may be non-reclaimable because: they are locked into memory, they + are anonymous pages for which no swap space exists, or they are anon + pages that are expensive to unmap [long anon_vma "related vma" list.] Index: linux-2.6.24-rc6-mm1/include/linux/page-flags.h =================================================================== --- linux-2.6.24-rc6-mm1.orig/include/linux/page-flags.h 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/include/linux/page-flags.h 2008-01-02 16:00:54.000000000 -0500 @@ -94,6 +94,7 @@ /* PG_readahead is only used for file reads; PG_reclaim is only for writes */ #define PG_readahead PG_reclaim /* Reminder to do async read-ahead */ + /* PG_owner_priv_1 users should have descriptive aliases */ #define PG_checked PG_owner_priv_1 /* Used by some filesystems */ #define PG_pinned PG_owner_priv_1 /* Xen pinned pagetable */ @@ -107,6 +108,8 @@ * 63 32 0 */ #define PG_uncached 31 /* Page has been mapped as uncached */ + +#define PG_noreclaim 30 /* Page is "non-reclaimable" */ #endif /* @@ -160,6 +163,7 @@ static inline void SetPageUptodate(struc #define SetPageActive(page) set_bit(PG_active, &(page)->flags) #define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) #define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags) +#define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags) #define PageSlab(page) test_bit(PG_slab, &(page)->flags) #define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags) @@ -261,6 +265,21 @@ static inline void __ClearPageTail(struc #define PageSwapCache(page) 0 #endif +#ifdef CONFIG_NORECLAIM +#define PageNoreclaim(page) test_bit(PG_noreclaim, &(page)->flags) +#define SetPageNoreclaim(page) set_bit(PG_noreclaim, &(page)->flags) +#define ClearPageNoreclaim(page) clear_bit(PG_noreclaim, &(page)->flags) +#define __ClearPageNoreclaim(page) __clear_bit(PG_noreclaim, &(page)->flags) +#define TestClearPageNoreclaim(page) test_and_clear_bit(PG_noreclaim, \ + &(page)->flags) +#else +#define PageNoreclaim(page) 0 +#define SetPageNoreclaim(page) +#define ClearPageNoreclaim(page) +#define __ClearPageNoreclaim(page) +#define TestClearPageNoreclaim(page) 0 +#endif + #define PageUncached(page) test_bit(PG_uncached, &(page)->flags) #define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) #define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) Index: linux-2.6.24-rc6-mm1/include/linux/mmzone.h =================================================================== --- linux-2.6.24-rc6-mm1.orig/include/linux/mmzone.h 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/include/linux/mmzone.h 2008-01-02 16:00:54.000000000 -0500 @@ -84,6 +84,11 @@ enum zone_stat_item { NR_ACTIVE_ANON, /* " " " " " */ NR_INACTIVE_FILE, /* " " " " " */ NR_ACTIVE_FILE, /* " " " " " */ +#ifdef CONFIG_NORECLAIM + NR_NORECLAIM, /* " " " " " */ +#else + NR_NORECLAIM=NR_ACTIVE_FILE, /* avoid compiler errors in dead code */ +#endif NR_ANON_PAGES, /* Mapped anonymous pages */ NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. only modified from process context */ @@ -123,10 +128,18 @@ enum lru_list { LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, - NR_LRU_LISTS }; +#ifdef CONFIG_NORECLAIM + LRU_NORECLAIM, +#else + LRU_NORECLAIM=LRU_ACTIVE_FILE, /* avoid compiler errors in dead code */ +#endif + NR_LRU_LISTS +}; #define for_each_lru(l) for (l = 0; l < NR_LRU_LISTS; l++) +#define for_each_reclaimable_lru(l) for (l = 0; l <= LRU_ACTIVE_FILE; l++) + static inline int is_file_lru(enum lru_list l) { BUILD_BUG_ON(LRU_INACTIVE_FILE != 2 || LRU_ACTIVE_FILE != 3); Index: linux-2.6.24-rc6-mm1/mm/page_alloc.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/page_alloc.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/page_alloc.c 2008-01-02 16:00:54.000000000 -0500 @@ -248,6 +248,9 @@ static void bad_page(struct page *page) 1 << PG_private | 1 << PG_locked | 1 << PG_active | +#ifdef CONFIG_NORECLAIM + 1 << PG_noreclaim | +#endif 1 << PG_dirty | 1 << PG_reclaim | 1 << PG_slab | @@ -482,6 +485,9 @@ static inline int free_pages_check(struc 1 << PG_swapcache | 1 << PG_writeback | 1 << PG_reserved | +#ifdef CONFIG_NORECLAIM + 1 << PG_noreclaim | +#endif 1 << PG_buddy )))) bad_page(page); if (PageDirty(page)) @@ -629,6 +635,9 @@ static int prep_new_page(struct page *pa 1 << PG_private | 1 << PG_locked | 1 << PG_active | +#ifdef CONFIG_NORECLAIM + 1 << PG_noreclaim | +#endif 1 << PG_dirty | 1 << PG_slab | 1 << PG_swapcache | Index: linux-2.6.24-rc6-mm1/include/linux/mm_inline.h =================================================================== --- linux-2.6.24-rc6-mm1.orig/include/linux/mm_inline.h 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/include/linux/mm_inline.h 2008-01-02 16:00:54.000000000 -0500 @@ -92,13 +92,36 @@ del_page_from_inactive_file_list(struct del_page_from_lru_list(zone, page, LRU_INACTIVE_FILE); } +#ifdef CONFIG_NORECLAIM +static inline void +add_page_to_noreclaim_list(struct zone *zone, struct page *page) +{ + add_page_to_lru_list(zone, page, LRU_NORECLAIM); +} + +static inline void +del_page_from_noreclaim_list(struct zone *zone, struct page *page) +{ + del_page_from_lru_list(zone, page, LRU_NORECLAIM); +} +#else +static inline void +add_page_to_noreclaim_list(struct zone *zone, struct page *page) { } + +static inline void +del_page_from_noreclaim_list(struct zone *zone, struct page *page) { } +#endif + static inline void del_page_from_lru(struct zone *zone, struct page *page) { enum lru_list l = LRU_INACTIVE_ANON; list_del(&page->lru); - if (PageActive(page)) { + if (PageNoreclaim(page)) { + __ClearPageNoreclaim(page); + l = LRU_NORECLAIM; + } else if (PageActive(page)) { __ClearPageActive(page); l = LRU_ACTIVE_ANON; } Index: linux-2.6.24-rc6-mm1/include/linux/swap.h =================================================================== --- linux-2.6.24-rc6-mm1.orig/include/linux/swap.h 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/include/linux/swap.h 2008-01-02 16:00:54.000000000 -0500 @@ -175,6 +175,13 @@ extern void FASTCALL(lru_cache_add_file( extern void FASTCALL(lru_cache_add_anon(struct page *)); extern void FASTCALL(lru_cache_add_active_file(struct page *)); extern void FASTCALL(lru_cache_add_active_anon(struct page *)); +extern void FASTCALL(lru_cache_add_active_or_noreclaim(struct page *page, + struct vm_area_struct *vma)); +#ifdef CONFIG_NORECLAIM +extern void FASTCALL(lru_cache_add_noreclaim(struct page *page)); +#else +static inline void lru_cache_add_noreclaim(struct page *page) { } +#endif extern void FASTCALL(activate_page(struct page *)); extern void FASTCALL(mark_page_accessed(struct page *)); extern void lru_add_drain(void); @@ -206,6 +213,16 @@ static inline int zone_reclaim(struct zo } #endif +#ifdef CONFIG_NORECLAIM +extern int page_reclaimable(struct page *page, struct vm_area_struct *vma); +#else +static inline int page_reclaimable(struct page *page, + struct vm_area_struct *vma) +{ + return 1; +} +#endif + extern int kswapd_run(int nid); #ifdef CONFIG_MMU Index: linux-2.6.24-rc6-mm1/include/linux/pagevec.h =================================================================== --- linux-2.6.24-rc6-mm1.orig/include/linux/pagevec.h 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/include/linux/pagevec.h 2008-01-02 16:00:54.000000000 -0500 @@ -27,6 +27,11 @@ void __pagevec_lru_add_file(struct pagev void __pagevec_lru_add_active_file(struct pagevec *pvec); void __pagevec_lru_add_anon(struct pagevec *pvec); void __pagevec_lru_add_active_anon(struct pagevec *pvec); +#ifdef CONFIG_NORECLAIM +void __pagevec_lru_add_noreclaim(struct pagevec *pvec); +#else +static inline void __pagevec_lru_add_noreclaim(struct pagevec *pvec) { } +#endif void pagevec_strip(struct pagevec *pvec); void pagevec_swap_free(struct pagevec *pvec); unsigned pagevec_lookup(struct pagevec *pvec, struct address_space *mapping, Index: linux-2.6.24-rc6-mm1/mm/swap.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/swap.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/swap.c 2008-01-02 16:00:54.000000000 -0500 @@ -119,7 +119,8 @@ static void pagevec_move_tail(struct pag zone = pagezone; spin_lock(&zone->lru_lock); } - if (PageLRU(page) && !PageActive(page)) { + if (PageLRU(page) && !PageActive(page) && \ + !PageNoreclaim(page)) { if (page_file_cache(page)) { list_move_tail(&page->lru, &zone->list[LRU_INACTIVE_FILE]); @@ -153,7 +154,7 @@ int rotate_reclaimable_page(struct page return 1; if (PageDirty(page)) return 1; - if (PageActive(page)) + if (PageActive(page) || PageNoreclaim(page)) return 1; if (!PageLRU(page)) return 1; @@ -179,7 +180,7 @@ void activate_page(struct page *page) struct zone *zone = page_zone(page); spin_lock_irq(&zone->lru_lock); - if (PageLRU(page) && !PageActive(page)) { + if (PageLRU(page) && !PageActive(page) && !PageNoreclaim(page)) { int lru = LRU_BASE; lru += page_file_cache(page); del_page_from_lru_list(zone, page, lru); @@ -202,7 +203,8 @@ void activate_page(struct page *page) */ void mark_page_accessed(struct page *page) { - if (!PageActive(page) && PageReferenced(page) && PageLRU(page)) { + if (!PageActive(page) && !PageNoreclaim(page) && + PageReferenced(page) && PageLRU(page)) { activate_page(page); ClearPageReferenced(page); } else if (!PageReferenced(page)) { @@ -256,6 +258,50 @@ void lru_cache_add_active_file(struct pa put_cpu_var(lru_add_active_file_pvecs); } +#ifdef CONFIG_NORECLAIM +static DEFINE_PER_CPU(struct pagevec, lru_add_noreclaim_pvecs) = { 0, }; + +void fastcall lru_cache_add_noreclaim(struct page *page) +{ + struct pagevec *pvec = &get_cpu_var(lru_add_noreclaim_pvecs); + + page_cache_get(page); + if (!pagevec_add(pvec, page)) + __pagevec_lru_add_noreclaim(pvec); + put_cpu_var(lru_add_noreclaim_pvecs); +} + +void fastcall lru_cache_add_active_or_noreclaim(struct page *page, + struct vm_area_struct *vma) +{ + if (page_reclaimable(page, vma)) { + if (page_file_cache(page)) + lru_cache_add_active_file(page); + else + lru_cache_add_active_anon(page); + } else + lru_cache_add_noreclaim(page); +} + +static inline void __drain_noreclaim_pvec(struct pagevec **pvec, int cpu) +{ + *pvec = &per_cpu(lru_add_noreclaim_pvecs, cpu); + if (pagevec_count(*pvec)) + __pagevec_lru_add_noreclaim(*pvec); +} +#else +void fastcall lru_cache_add_active_or_noreclaim(struct page *page, + struct vm_area_struct *vma) +{ + if (page_file_cache(page)) + lru_cache_add_active_file(page); + else + lru_cache_add_active_anon(page); +} + +static inline void __drain_noreclaim_pvec(struct pagevec **pvec, int cpu) { } +#endif + /* * Drain pages out of the cpu's pagevecs. * Either "cpu" is the current CPU, and preemption has already been @@ -290,6 +336,8 @@ static void drain_cpu_pagevecs(int cpu) pagevec_move_tail(pvec); local_irq_restore(flags); } + + __drain_noreclaim_pvec(&pvec, cpu); } void lru_add_drain(void) @@ -361,6 +409,8 @@ void release_pages(struct page **pages, if (PageLRU(page)) { struct zone *pagezone = page_zone(page); + int is_lru_page; + if (pagezone != zone) { if (zone) spin_unlock_irqrestore(&zone->lru_lock, @@ -368,8 +418,10 @@ void release_pages(struct page **pages, zone = pagezone; spin_lock_irqsave(&zone->lru_lock, flags); } - VM_BUG_ON(!PageLRU(page)); - __ClearPageLRU(page); + is_lru_page = PageLRU(page); + VM_BUG_ON(!(is_lru_page)); + if (is_lru_page) + __ClearPageLRU(page); del_page_from_lru(zone, page); } @@ -448,6 +500,7 @@ void __pagevec_lru_add_file(struct pagev zone = pagezone; spin_lock_irq(&zone->lru_lock); } + VM_BUG_ON(PageActive(page) || PageNoreclaim(page)); VM_BUG_ON(PageLRU(page)); SetPageLRU(page); add_page_to_inactive_file_list(zone, page); @@ -476,7 +529,7 @@ void __pagevec_lru_add_active_file(struc } VM_BUG_ON(PageLRU(page)); SetPageLRU(page); - VM_BUG_ON(PageActive(page)); + VM_BUG_ON(PageActive(page) || PageNoreclaim(page)); SetPageActive(page); add_page_to_active_file_list(zone, page); } @@ -538,6 +591,35 @@ void __pagevec_lru_add_active_anon(struc pagevec_reinit(pvec); } +#ifdef CONFIG_NORECLAIM +void __pagevec_lru_add_noreclaim(struct pagevec *pvec) +{ + int i; + struct zone *zone = NULL; + + for (i = 0; i < pagevec_count(pvec); i++) { + struct page *page = pvec->pages[i]; + struct zone *pagezone = page_zone(page); + + if (pagezone != zone) { + if (zone) + spin_unlock_irq(&zone->lru_lock); + zone = pagezone; + spin_lock_irq(&zone->lru_lock); + } + VM_BUG_ON(PageLRU(page)); + SetPageLRU(page); + VM_BUG_ON(PageActive(page) || PageNoreclaim(page)); + SetPageNoreclaim(page); + add_page_to_noreclaim_list(zone, page); + } + if (zone) + spin_unlock_irq(&zone->lru_lock); + release_pages(pvec->pages, pvec->nr, pvec->cold); + pagevec_reinit(pvec); +} +#endif + /* * Try to drop buffers from the pages in a pagevec */ Index: linux-2.6.24-rc6-mm1/mm/migrate.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/migrate.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/migrate.c 2008-01-02 16:00:54.000000000 -0500 @@ -52,9 +52,18 @@ int migrate_prep(void) return 0; } +/* + * move_to_lru() - place @page onto appropriate lru list + * based on preserved page flags: active, noreclaim, none + */ static inline void move_to_lru(struct page *page) { - if (PageActive(page)) { + if (PageNoreclaim(page)) { + VM_BUG_ON(PageActive(page)); + ClearPageNoreclaim(page); + lru_cache_add_noreclaim(page); + } else if (PageActive(page)) { + VM_BUG_ON(PageNoreclaim(page)); /* race ? */ /* * lru_cache_add_active checks that * the PG_active bit is off. @@ -65,6 +74,7 @@ static inline void move_to_lru(struct pa else lru_cache_add_active_anon(page); } else { + VM_BUG_ON(PageNoreclaim(page)); /* race ? */ if (page_file_cache(page)) lru_cache_add_file(page); else @@ -341,8 +351,11 @@ static void migrate_page_copy(struct pag SetPageReferenced(newpage); if (PageUptodate(page)) SetPageUptodate(newpage); - if (PageActive(page)) + if (TestClearPageActive(page)) { + VM_BUG_ON(PageNoreclaim(page)); SetPageActive(newpage); + } else if (TestClearPageNoreclaim(page)) + SetPageNoreclaim(newpage); if (PageChecked(page)) SetPageChecked(newpage); if (PageMappedToDisk(page)) @@ -356,7 +369,6 @@ static void migrate_page_copy(struct pag #ifdef CONFIG_SWAP ClearPageSwapCache(page); #endif - ClearPageActive(page); ClearPagePrivate(page); set_page_private(page, 0); page->mapping = NULL; Index: linux-2.6.24-rc6-mm1/mm/vmscan.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/vmscan.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/vmscan.c 2008-01-02 16:01:08.000000000 -0500 @@ -480,6 +480,11 @@ static unsigned long shrink_page_list(st sc->nr_scanned++; + if (!page_reclaimable(page, NULL)) { + SetPageNoreclaim(page); + goto keep_locked; + } + if (!sc->may_swap && page_mapped(page)) goto keep_locked; @@ -582,7 +587,7 @@ static unsigned long shrink_page_list(st * possible for a page to have PageDirty set, but it is actually * clean (all its buffers are clean). This happens if the * buffers were written out directly, with submit_bh(). ext3 - * will do this, as well as the blockdev mapping. + * will do this, as well as the blockdev mapping. * try_to_release_page() will discover that cleanness and will * drop the buffers and mark the page clean - it can be freed. * @@ -614,6 +619,7 @@ activate_locked: /* Not a candidate for swapping, so reclaim swap space. */ if (PageSwapCache(page) && vm_swap_full()) remove_exclusive_swap_page(page); + VM_BUG_ON(PageActive(page)); SetPageActive(page); pgactivate++; keep_locked: @@ -664,6 +670,14 @@ int __isolate_lru_page(struct page *page if (mode != ISOLATE_BOTH && (!page_file_cache(page) != !file)) return ret; + /* + * Non-reclaimable pages shouldn't make it onto either the active + * nor the inactive list. However, when doing lumpy reclaim of + * higher order pages we can still run into them. + */ + if (PageNoreclaim(page)) + return ret; + ret = -EBUSY; if (likely(get_page_unless_zero(page))) { /* @@ -775,7 +789,7 @@ static unsigned long isolate_lru_pages(u /* else it is being freed elsewhere */ list_move(&cursor_page->lru, src); default: - break; + break; /* ! on LRU or wrong list */ } } } @@ -831,9 +845,10 @@ static unsigned long clear_active_flags( * refcount on the page, which is a fundamentnal difference from * isolate_lru_pages (which is called without a stable reference). * - * The returned page will have PageLru() cleared, and PageActive set, - * if it was found on the active list. This flag generally will need to be - * cleared by the caller before letting the page go. + * The returned page will have the PageLru() cleared, and the PageActive or + * PageNoreclaim will be set, if it was found on the active or noreclaim list, + * respectively. This flag generally will need to be cleared by the caller + * before letting the page go. * * The vmstat page counts corresponding to the list on which the page was * found will be decremented. @@ -857,7 +872,13 @@ int isolate_lru_page(struct page *page) ret = 0; ClearPageLRU(page); + /* Calculate the LRU list for normal pages ... */ lru += page_file_cache(page) + !!PageActive(page); + + /* ... except NoReclaim, which has its own list. */ + if (PageNoreclaim(page)) + lru = LRU_NORECLAIM; + del_page_from_lru_list(zone, page, lru); } spin_unlock_irq(&zone->lru_lock); @@ -957,14 +978,19 @@ static unsigned long shrink_inactive_lis VM_BUG_ON(PageLRU(page)); SetPageLRU(page); list_del(&page->lru); - if (page_file_cache(page)) { - lru += LRU_FILE; - zone->recent_rotated_file++; + if (PageNoreclaim(page)) { + VM_BUG_ON(PageActive(page)); + lru = LRU_NORECLAIM; } else { - zone->recent_rotated_anon++; + if (page_file_cache(page)) { + lru += LRU_FILE; + zone->recent_rotated_file++; + } else { + zone->recent_rotated_anon++; + } + if (PageActive(page)) + lru += LRU_ACTIVE; } - if (PageActive(page)) - lru += LRU_ACTIVE; add_page_to_lru_list(zone, page, lru); if (!pagevec_add(&pvec, page)) { spin_unlock_irq(&zone->lru_lock); @@ -1058,6 +1084,13 @@ static void shrink_active_list(unsigned cond_resched(); page = lru_to_page(&l_hold); list_del(&page->lru); + + if (!page_reclaimable(page, NULL)) { + /* Non-reclaimable pages go onto their own list. */ + list_add(&page->lru, &list[LRU_NORECLAIM]); + continue; + } + if (page_referenced(page, 0, sc->mem_cgroup)) { if (file) /* Referenced file pages stay active. */ @@ -1144,6 +1177,33 @@ static void shrink_active_list(unsigned zone->recent_rotated_anon += pgmoved; } +#ifdef CONFIG_NORECLAIM + pgmoved = 0; + while (!list_empty(&list[LRU_NORECLAIM])) { + page = lru_to_page(&list[LRU_NORECLAIM]); + prefetchw_prev_lru_page(page, &list[LRU_NORECLAIM], flags); + + VM_BUG_ON(PageLRU(page)); + SetPageLRU(page); + VM_BUG_ON(!PageActive(page)); + ClearPageActive(page); + VM_BUG_ON(PageNoreclaim(page)); + SetPageNoreclaim(page); + + list_move(&page->lru, &zone->list[LRU_NORECLAIM]); + pgmoved++; + if (!pagevec_add(&pvec, page)) { + __mod_zone_page_state(zone, NR_NORECLAIM, pgmoved); +//TODO: count these as deactivations? + pgmoved = 0; + spin_unlock_irq(&zone->lru_lock); + __pagevec_release(&pvec); + spin_lock_irq(&zone->lru_lock); + } + } + __mod_zone_page_state(zone, NR_NORECLAIM, pgmoved); +#endif + __count_zone_vm_events(PGREFILL, zone, pgscanned); __count_vm_events(PGDEACTIVATE, pgdeactivate); spin_unlock_irq(&zone->lru_lock); @@ -1247,7 +1307,7 @@ static unsigned long shrink_zone(int pri get_scan_ratio(zone, sc, percent); - for_each_lru(l) { + for_each_reclaimable_lru(l) { if (scan_global_lru(sc)) { int file = is_file_lru(l); /* @@ -1273,8 +1333,8 @@ static unsigned long shrink_zone(int pri } while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || - nr[LRU_INACTIVE_FILE]) { - for_each_lru(l) { + nr[LRU_INACTIVE_FILE]) { + for_each_reclaimable_lru(l) { if (nr[l]) { nr_to_scan = min(nr[l], (unsigned long)sc->swap_cluster_max); @@ -1814,8 +1874,8 @@ static unsigned long shrink_all_zones(un if (zone_is_all_unreclaimable(zone) && prio != DEF_PRIORITY) continue; - for_each_lru(l) { - /* For pass = 0 we don't shrink the active list */ + for_each_reclaimable_lru(l) { + /* For pass = 0, we don't shrink the active list */ if (pass == 0 && (l == LRU_ACTIVE_ANON || l == LRU_ACTIVE_FILE)) continue; @@ -2161,3 +2221,29 @@ int zone_reclaim(struct zone *zone, gfp_ return ret; } #endif + +#ifdef CONFIG_NORECLAIM +/* + * page_reclaimable(struct page *page, struct vm_area_struct *vma) + * Test whether page is reclaimable--i.e., should be placed on active/inactive + * lists vs noreclaim list. + * + * @page - page to test + * @vma - vm area in which page is/will be mapped. May be NULL. + * If !NULL, called from fault path. + * + * Reasons page might not be reclaimable: + * TODO - later patches + * + * TODO: specify locking assumptions + */ +int page_reclaimable(struct page *page, struct vm_area_struct *vma) +{ + + VM_BUG_ON(PageNoreclaim(page)); + + /* TODO: test page [!]reclaimable conditions */ + + return 1; +} +#endif Index: linux-2.6.24-rc6-mm1/mm/mempolicy.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/mempolicy.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/mempolicy.c 2008-01-02 16:00:54.000000000 -0500 @@ -1912,7 +1912,7 @@ static void gather_stats(struct page *pa if (PageSwapCache(page)) md->swapcache++; - if (PageActive(page)) + if (PageActive(page) || PageNoreclaim(page)) md->active++; if (PageWriteback(page)) Index: linux-2.6.24-rc6-mm1/mm/memcontrol.c =================================================================== --- linux-2.6.24-rc6-mm1.orig/mm/memcontrol.c 2008-01-02 16:00:39.000000000 -0500 +++ linux-2.6.24-rc6-mm1/mm/memcontrol.c 2008-01-02 16:00:54.000000000 -0500 @@ -520,6 +520,10 @@ unsigned long mem_cgroup_isolate_pages(u scan++; list_move(&pc->lru, &pc_list); +//TODO: for now, don't isolate non-reclaimable pages. When/if +// mem controller supports a noreclaim list, we'll need to make +// at least ISOLATE_ACTIVE visible outside of vm_scan and pass +// the 'take_nonreclaimable' flag accordingly. if (__isolate_lru_page(page, mode, file) == 0) { list_move(&page->lru, dst); nr_taken++; -- All Rights Reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/