From f7232154198f928fc25f420d6190468212a7632a Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 23 May 2008 13:04:21 -0700 Subject: mm: don't drop a partial page in a zone's memory map size In a zone's present pages number, account for all pages occupied by the memory map, including a partial. Signed-off-by: Johannes Weiner Cc: KAMEZAWA Hiroyuki Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 63835579323a..035300299f94 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3378,7 +3378,8 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, * is used by this zone for memmap. This affects the watermark * and per-cpu initialisations */ - memmap_pages = (size * sizeof(struct page)) >> PAGE_SHIFT; + memmap_pages = + PAGE_ALIGN(size * sizeof(struct page)) >> PAGE_SHIFT; if (realsize >= memmap_pages) { realsize -= memmap_pages; printk(KERN_DEBUG -- cgit v1.2.3 From 7eb54824b76793dd86afb54f182ef9aa64b3a45a Mon Sep 17 00:00:00 2001 From: Andy Whitcroft Date: Fri, 23 May 2008 13:04:50 -0700 Subject: zonelists: handle a node zonelist with no applicable entries When booting 2.6.26-rc3 on a multi-node x86_32 numa system we are seeing panics when trying node local allocations: BUG: unable to handle kernel NULL pointer dereference at 0000034c IP: [] get_page_from_freelist+0x4a/0x18e *pdpt = 00000000013a7001 *pde = 0000000000000000 Oops: 0000 [#1] SMP Modules linked in: Pid: 0, comm: swapper Not tainted (2.6.26-rc3-00003-g5abc28d #82) EIP: 0060:[] EFLAGS: 00010282 CPU: 0 EIP is at get_page_from_freelist+0x4a/0x18e EAX: c1371ed8 EBX: 00000000 ECX: 00000000 EDX: 00000000 ESI: f7801180 EDI: 00000000 EBP: 00000000 ESP: c1371ec0 DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 Process swapper (pid: 0, ti=c1370000 task=c12f5b40 task.ti=c1370000) Stack: 00000000 00000000 00000000 00000000 000612d0 000412d0 00000000 000412d0 f7801180 f7c0101c f7c01018 c10426e4 f7c01018 00000001 00000044 00000000 00000001 c12f5b40 00000001 00000010 00000000 000412d0 00000286 000412d0 Call Trace: [] __alloc_pages_internal+0x99/0x378 [] __alloc_pages+0x7/0x9 [] kmem_getpages+0x66/0xef [] cache_grow+0x8f/0x123 [] ____cache_alloc_node+0xb9/0xe4 [] kmem_cache_alloc_node+0x92/0xd2 [] setup_cpu_cache+0xaf/0x177 [] kmem_cache_create+0x2c8/0x353 [] kmem_cache_init+0x1ce/0x3ad [] start_kernel+0x178/0x1ee This occurs when we are scanning the zonelists looking for a ZONE_NORMAL page. In this system there is only ZONE_DMA and ZONE_NORMAL memory on node 0, all other nodes are mapped above 4GB physical. Here is a dump of the zonelists from this system: zonelists pgdat=c1400000 0: c14006c0:2 f7c006c0:2 f7e006c0:2 c1400360:1 c1400000:0 1: c14006c0:2 c1400360:1 c1400000:0 zonelists pgdat=f7c00000 0: f7c006c0:2 f7e006c0:2 c14006c0:2 c1400360:1 c1400000:0 1: f7c006c0:2 zonelists pgdat=f7e00000 0: f7e006c0:2 c14006c0:2 f7c006c0:2 c1400360:1 c1400000:0 1: f7e006c0:2 When performing a node local allocation we call get_page_from_freelist() looking for a page. It in turn calls first_zones_zonelist() which returns a preferred_zone. Where there are no applicable zones this will be NULL. However we use this unconditionally, leading to this panic. Where there are no applicable zones there is no possibility of a successful allocation, so simply fail the allocation. Signed-off-by: Andy Whitcroft Acked-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 035300299f94..7f4c66ff65b7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1396,6 +1396,9 @@ get_page_from_freelist(gfp_t gfp_mask, nodemask_t *nodemask, unsigned int order, (void)first_zones_zonelist(zonelist, high_zoneidx, nodemask, &preferred_zone); + if (!preferred_zone) + return NULL; + classzone_idx = zone_idx(preferred_zone); zonelist_scan: -- cgit v1.2.3 From cd94b9dbfa300fc42e45f230010623fc08d59563 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 23 May 2008 13:04:52 -0700 Subject: memory hotplug: fix early allocation handling Trying to add memory via add_memory() from within an initcall function results in bootmem alloc of 163840 bytes failed! Kernel panic - not syncing: Out of memory This is caused by zone_wait_table_init() which uses system_state to decide if it should use the bootmem allocator or not. When initcalls are handled the system_state is still SYSTEM_BOOTING but the bootmem allocator doesn't work anymore. So the allocation will fail. To fix this use slab_is_available() instead as indicator like we do it everywhere else. [akpm@linux-foundation.org: coding-style fix] Reviewed-by: Andy Whitcroft Cc: Dave Hansen Cc: Gerald Schaefer Cc: KAMEZAWA Hiroyuki Acked-by: Yasunori Goto Signed-off-by: Heiko Carstens Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7f4c66ff65b7..8e83f02cd2d3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2807,7 +2807,7 @@ int zone_wait_table_init(struct zone *zone, unsigned long zone_size_pages) alloc_size = zone->wait_table_hash_nr_entries * sizeof(wait_queue_head_t); - if (system_state == SYSTEM_BOOTING) { + if (!slab_is_available()) { zone->wait_table = (wait_queue_head_t *) alloc_bootmem_node(pgdat, alloc_size); } else { -- cgit v1.2.3 From dfa7e20cc0d1a7a620def4dce97de1ae5375f99b Mon Sep 17 00:00:00 2001 From: Russ Anderson Date: Mon, 9 Jun 2008 11:18:45 -0500 Subject: mm: Minor clean-up of page flags in mm/page_alloc.c Minor source code cleanup of page flags in mm/page_alloc.c. Move the definition of the groups of bits to page-flags.h. The purpose of this clean up is that the next patch will conditionally add a page flag to the groups. Doing that in a header file is cleaner than adding #ifdefs to the C code. Signed-off-by: Russ Anderson Signed-off-by: Linus Torvalds --- include/linux/page-flags.h | 24 ++++++++++++++++++++++++ mm/page_alloc.c | 34 +++------------------------------- 2 files changed, 27 insertions(+), 31 deletions(-) (limited to 'mm/page_alloc.c') diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 590cff32415d..f31debfac926 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -306,5 +306,29 @@ static inline void __ClearPageTail(struct page *page) } #endif /* !PAGEFLAGS_EXTENDED */ + +#define PAGE_FLAGS (1 << PG_lru | 1 << PG_private | 1 << PG_locked | \ + 1 << PG_buddy | 1 << PG_writeback | \ + 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active) + +/* + * Flags checked in bad_page(). Pages on the free list should not have + * these flags set. It they are, there is a problem. + */ +#define PAGE_FLAGS_CLEAR_WHEN_BAD (PAGE_FLAGS | 1 << PG_reclaim | 1 << PG_dirty) + +/* + * Flags checked when a page is freed. Pages being freed should not have + * these flags set. It they are, there is a problem. + */ +#define PAGE_FLAGS_CHECK_AT_FREE (PAGE_FLAGS | 1 << PG_reserved) + +/* + * Flags checked when a page is prepped for return by the page allocator. + * Pages being prepped should not have these flags set. It they are, there + * is a problem. + */ +#define PAGE_FLAGS_CHECK_AT_PREP (PAGE_FLAGS | 1 << PG_reserved | 1 << PG_dirty) + #endif /* !__GENERATING_BOUNDS_H */ #endif /* PAGE_FLAGS_H */ diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8e83f02cd2d3..2f552955a02f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -237,16 +237,7 @@ static void bad_page(struct page *page) printk(KERN_EMERG "Trying to fix it up, but a reboot is needed\n" KERN_EMERG "Backtrace:\n"); dump_stack(); - page->flags &= ~(1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_dirty | - 1 << PG_reclaim | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_buddy ); + page->flags &= ~PAGE_FLAGS_CLEAR_WHEN_BAD; set_page_count(page, 0); reset_page_mapcount(page); page->mapping = NULL; @@ -463,16 +454,7 @@ static inline int free_pages_check(struct page *page) (page->mapping != NULL) | (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | - (page->flags & ( - 1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_reserved | - 1 << PG_buddy )))) + (page->flags & PAGE_FLAGS_CHECK_AT_FREE))) bad_page(page); if (PageDirty(page)) __ClearPageDirty(page); @@ -616,17 +598,7 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) (page->mapping != NULL) | (page_get_page_cgroup(page) != NULL) | (page_count(page) != 0) | - (page->flags & ( - 1 << PG_lru | - 1 << PG_private | - 1 << PG_locked | - 1 << PG_active | - 1 << PG_dirty | - 1 << PG_slab | - 1 << PG_swapcache | - 1 << PG_writeback | - 1 << PG_reserved | - 1 << PG_buddy )))) + (page->flags & PAGE_FLAGS_CHECK_AT_PREP))) bad_page(page); /* -- cgit v1.2.3 From 494de90098784b8e2797598cefdd34188884ec2e Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 3 Jul 2008 05:27:51 +0100 Subject: Do not overwrite nr_zones on !NUMA when initialising zlcache_ptr The non-NUMA case of build_zonelist_cache() would initialize the zlcache_ptr for both node_zonelists[] to NULL. Which is problematic, since non-NUMA only has a single node_zonelists[] entry, and trying to zero the non-existent second one just overwrote the nr_zones field instead. As kswapd uses this value to determine what reclaim work is necessary, the result is that kswapd never reclaims. This causes processes to stall frequently in low-memory situations as they always direct reclaim. This patch initialises zlcache_ptr correctly. Signed-off-by: Mel Gorman Tested-by: Dan Williams [ Simplified patch a bit ] Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 1 - 1 file changed, 1 deletion(-) (limited to 'mm/page_alloc.c') diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2f552955a02f..f32fae3121f0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2328,7 +2328,6 @@ static void build_zonelists(pg_data_t *pgdat) static void build_zonelist_cache(pg_data_t *pgdat) { pgdat->node_zonelists[0].zlcache_ptr = NULL; - pgdat->node_zonelists[1].zlcache_ptr = NULL; } #endif /* CONFIG_NUMA */ -- cgit v1.2.3