--- linux-2.6.33/scripts/mod/modpost.c~ 2010-02-24 19:52:17.000000000 +0100 +++ linux-2.6.33/scripts/mod/modpost.c 2010-03-07 14:26:47.242168558 +0100 @@ -15,7 +15,8 @@ #include #include #include "modpost.h" -#include "../../include/generated/autoconf.h" +// PLD architectures don't use CONFIG_SYMBOL_PREFIX +//#include "../../include/generated/autoconf.h" #include "../../include/linux/license.h" /* Some toolchains use a `_' prefix for all user symbols. */ --- linux-3.0/scripts/kconfig/lxdialog/check-lxdialog.sh~ 2011-07-22 04:17:23.000000000 +0200 +++ linux-3.0/scripts/kconfig/lxdialog/check-lxdialog.sh 2011-08-25 21:26:04.799150642 +0200 @@ -9,6 +9,12 @@ $cc -print-file-name=lib${lib}.${ext} | grep -q / if [ $? -eq 0 ]; then echo "-l${lib}" + for libt in tinfow tinfo ; do + $cc -print-file-name=lib${libt}.${ext} | grep -q / + if [ $? -eq 0 ]; then + echo "-l${libt}" + fi + done exit fi done From 7a29ac474a47eb8cf212b45917683ae89d6fa13b Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 10 Nov 2015 10:10:34 +1100 Subject: xfs: give all workqueues rescuer threads We're consistently hitting deadlocks here with XFS on recent kernels. After some digging through the crash files, it looks like everyone in the system is waiting for XFS to reclaim memory. Something like this: PID: 2733434 TASK: ffff8808cd242800 CPU: 19 COMMAND: "java" #0 [ffff880019c53588] __schedule at ffffffff818c4df2 #1 [ffff880019c535d8] schedule at ffffffff818c5517 #2 [ffff880019c535f8] _xfs_log_force_lsn at ffffffff81316348 #3 [ffff880019c53688] xfs_log_force_lsn at ffffffff813164fb #4 [ffff880019c536b8] xfs_iunpin_wait at ffffffff8130835e #5 [ffff880019c53728] xfs_reclaim_inode at ffffffff812fd453 #6 [ffff880019c53778] xfs_reclaim_inodes_ag at ffffffff812fd8c7 #7 [ffff880019c53928] xfs_reclaim_inodes_nr at ffffffff812fe433 #8 [ffff880019c53958] xfs_fs_free_cached_objects at ffffffff8130d3b9 #9 [ffff880019c53968] super_cache_scan at ffffffff811a6f73 #10 [ffff880019c539c8] shrink_slab at ffffffff811460e6 #11 [ffff880019c53aa8] shrink_zone at ffffffff8114a53f #12 [ffff880019c53b48] do_try_to_free_pages at ffffffff8114a8ba #13 [ffff880019c53be8] try_to_free_pages at ffffffff8114ad5a #14 [ffff880019c53c78] __alloc_pages_nodemask at ffffffff8113e1b8 #15 [ffff880019c53d88] alloc_kmem_pages_node at ffffffff8113e671 #16 [ffff880019c53dd8] copy_process at ffffffff8104f781 #17 [ffff880019c53ec8] do_fork at ffffffff8105129c #18 [ffff880019c53f38] sys_clone at ffffffff810515b6 #19 [ffff880019c53f48] stub_clone at ffffffff818c8e4d xfs_log_force_lsn is waiting for logs to get cleaned, which is waiting for IO, which is waiting for workers to complete the IO which is waiting for worker threads that don't exist yet: PID: 2752451 TASK: ffff880bd6bdda00 CPU: 37 COMMAND: "kworker/37:1" #0 [ffff8808d20abbb0] __schedule at ffffffff818c4df2 #1 [ffff8808d20abc00] schedule at ffffffff818c5517 #2 [ffff8808d20abc20] schedule_timeout at ffffffff818c7c6c #3 [ffff8808d20abcc0] wait_for_completion_killable at ffffffff818c6495 #4 [ffff8808d20abd30] kthread_create_on_node at ffffffff8106ec82 #5 [ffff8808d20abdf0] create_worker at ffffffff8106752f #6 [ffff8808d20abe40] worker_thread at ffffffff810699be #7 [ffff8808d20abec0] kthread at ffffffff8106ef59 #8 [ffff8808d20abf50] ret_from_fork at ffffffff818c8ac8 I think we should be using WQ_MEM_RECLAIM to make sure this thread pool makes progress when we're not able to allocate new workers. [dchinner: make all workqueues WQ_MEM_RECLAIM] Signed-off-by: Chris Mason Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/xfs_super.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 29531ec..65fbfb7 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -838,17 +838,18 @@ xfs_init_mount_workqueues( goto out_destroy_unwritten; mp->m_reclaim_workqueue = alloc_workqueue("xfs-reclaim/%s", - WQ_FREEZABLE, 0, mp->m_fsname); + WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname); if (!mp->m_reclaim_workqueue) goto out_destroy_cil; mp->m_log_workqueue = alloc_workqueue("xfs-log/%s", - WQ_FREEZABLE|WQ_HIGHPRI, 0, mp->m_fsname); + WQ_MEM_RECLAIM|WQ_FREEZABLE|WQ_HIGHPRI, 0, + mp->m_fsname); if (!mp->m_log_workqueue) goto out_destroy_reclaim; mp->m_eofblocks_workqueue = alloc_workqueue("xfs-eofblocks/%s", - WQ_FREEZABLE, 0, mp->m_fsname); + WQ_MEM_RECLAIM|WQ_FREEZABLE, 0, mp->m_fsname); if (!mp->m_eofblocks_workqueue) goto out_destroy_log; -- cgit v0.11.2 commit c2d42c16ad83006a706d83e51a7268db04af733a Author: Andrew Morton Date: Thu Nov 5 18:48:43 2015 -0800 mm/vmstat.c: uninline node_page_state() With x86_64 (config http://ozlabs.org/~akpm/config-akpm2.txt) and old gcc (4.4.4), drivers/base/node.c:node_read_meminfo() is using 2344 bytes of stack. Uninlining node_page_state() reduces this to 440 bytes. The stack consumption issue is fixed by newer gcc (4.8.4) however with that compiler this patch reduces the node.o text size from 7314 bytes to 4578. Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index 82e7db7..49dfe40 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -161,30 +161,8 @@ static inline unsigned long zone_page_state_snapshot(struct zone *zone, } #ifdef CONFIG_NUMA -/* - * Determine the per node value of a stat item. This function - * is called frequently in a NUMA machine, so try to be as - * frugal as possible. - */ -static inline unsigned long node_page_state(int node, - enum zone_stat_item item) -{ - struct zone *zones = NODE_DATA(node)->node_zones; - - return -#ifdef CONFIG_ZONE_DMA - zone_page_state(&zones[ZONE_DMA], item) + -#endif -#ifdef CONFIG_ZONE_DMA32 - zone_page_state(&zones[ZONE_DMA32], item) + -#endif -#ifdef CONFIG_HIGHMEM - zone_page_state(&zones[ZONE_HIGHMEM], item) + -#endif - zone_page_state(&zones[ZONE_NORMAL], item) + - zone_page_state(&zones[ZONE_MOVABLE], item); -} +extern unsigned long node_page_state(int node, enum zone_stat_item item); extern void zone_statistics(struct zone *, struct zone *, gfp_t gfp); #else diff --git a/mm/vmstat.c b/mm/vmstat.c index fbf1448..ffcb4f5 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -591,6 +591,28 @@ void zone_statistics(struct zone *preferred_zone, struct zone *z, gfp_t flags) else __inc_zone_state(z, NUMA_OTHER); } + +/* + * Determine the per node value of a stat item. + */ +unsigned long node_page_state(int node, enum zone_stat_item item) +{ + struct zone *zones = NODE_DATA(node)->node_zones; + + return +#ifdef CONFIG_ZONE_DMA + zone_page_state(&zones[ZONE_DMA], item) + +#endif +#ifdef CONFIG_ZONE_DMA32 + zone_page_state(&zones[ZONE_DMA32], item) + +#endif +#ifdef CONFIG_HIGHMEM + zone_page_state(&zones[ZONE_HIGHMEM], item) + +#endif + zone_page_state(&zones[ZONE_NORMAL], item) + + zone_page_state(&zones[ZONE_MOVABLE], item); +} + #endif #ifdef CONFIG_COMPACTION commit 016c13daa5c9e4827eca703e2f0621c131f2cca3 Author: Mel Gorman Date: Fri Nov 6 16:28:18 2015 -0800 mm, page_alloc: use masks and shifts when converting GFP flags to migrate types This patch redefines which GFP bits are used for specifying mobility and the order of the migrate types. Once redefined it's possible to convert GFP flags to a migrate type with a simple mask and shift. The only downside is that readers of OOM kill messages and allocation failures may have been used to the existing values but scripts/gfp-translate will help. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Christoph Lameter Cc: David Rientjes Cc: Johannes Weiner Cc: Michal Hocko Cc: Vitaly Wool Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/include/linux/gfp.h b/include/linux/gfp.h index f92cbd2..440fca3 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -14,7 +14,7 @@ struct vm_area_struct; #define ___GFP_HIGHMEM 0x02u #define ___GFP_DMA32 0x04u #define ___GFP_MOVABLE 0x08u -#define ___GFP_WAIT 0x10u +#define ___GFP_RECLAIMABLE 0x10u #define ___GFP_HIGH 0x20u #define ___GFP_IO 0x40u #define ___GFP_FS 0x80u @@ -29,7 +29,7 @@ struct vm_area_struct; #define ___GFP_NOMEMALLOC 0x10000u #define ___GFP_HARDWALL 0x20000u #define ___GFP_THISNODE 0x40000u -#define ___GFP_RECLAIMABLE 0x80000u +#define ___GFP_WAIT 0x80000u #define ___GFP_NOACCOUNT 0x100000u #define ___GFP_NOTRACK 0x200000u #define ___GFP_NO_KSWAPD 0x400000u @@ -126,6 +126,7 @@ struct vm_area_struct; /* This mask makes up all the page movable related flags */ #define GFP_MOVABLE_MASK (__GFP_RECLAIMABLE|__GFP_MOVABLE) +#define GFP_MOVABLE_SHIFT 3 /* Control page allocator reclaim behavior */ #define GFP_RECLAIM_MASK (__GFP_WAIT|__GFP_HIGH|__GFP_IO|__GFP_FS|\ @@ -152,14 +153,15 @@ struct vm_area_struct; /* Convert GFP flags to their corresponding migrate type */ static inline int gfpflags_to_migratetype(const gfp_t gfp_flags) { - WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK); + VM_WARN_ON((gfp_flags & GFP_MOVABLE_MASK) == GFP_MOVABLE_MASK); + BUILD_BUG_ON((1UL << GFP_MOVABLE_SHIFT) != ___GFP_MOVABLE); + BUILD_BUG_ON((___GFP_MOVABLE >> GFP_MOVABLE_SHIFT) != MIGRATE_MOVABLE); if (unlikely(page_group_by_mobility_disabled)) return MIGRATE_UNMOVABLE; /* Group based on mobility */ - return (((gfp_flags & __GFP_MOVABLE) != 0) << 1) | - ((gfp_flags & __GFP_RECLAIMABLE) != 0); + return (gfp_flags & GFP_MOVABLE_MASK) >> GFP_MOVABLE_SHIFT; } #ifdef CONFIG_HIGHMEM diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index e326843..38bed71 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -37,8 +37,8 @@ enum { MIGRATE_UNMOVABLE, - MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, + MIGRATE_RECLAIMABLE, MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ MIGRATE_RESERVE = MIGRATE_PCPTYPES, #ifdef CONFIG_CMA commit 974a786e63c96a2401a78ddba926f34c128474f1 Author: Mel Gorman Date: Fri Nov 6 16:28:34 2015 -0800 mm, page_alloc: remove MIGRATE_RESERVE MIGRATE_RESERVE preserves an old property of the buddy allocator that existed prior to fragmentation avoidance -- min_free_kbytes worth of pages tended to remain contiguous until the only alternative was to fail the allocation. At the time it was discovered that high-order atomic allocations relied on this property so MIGRATE_RESERVE was introduced. A later patch will introduce an alternative MIGRATE_HIGHATOMIC so this patch deletes MIGRATE_RESERVE and supporting code so it'll be easier to review. Note that this patch in isolation may look like a false regression if someone was bisecting high-order atomic allocation failures. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Cc: Christoph Lameter Cc: David Rientjes Cc: Johannes Weiner Cc: Michal Hocko Cc: Vitaly Wool Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 1e88aae..b86cfa3 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -39,8 +39,6 @@ enum { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RECLAIMABLE, - MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ - MIGRATE_RESERVE = MIGRATE_PCPTYPES, #ifdef CONFIG_CMA /* * MIGRATE_CMA migration type is designed to mimic the way @@ -63,6 +61,8 @@ enum { MIGRATE_TYPES }; +#define MIGRATE_PCPTYPES (MIGRATE_RECLAIMABLE+1) + #ifdef CONFIG_CMA # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) #else @@ -429,12 +429,6 @@ struct zone { const char *name; - /* - * Number of MIGRATE_RESERVE page block. To maintain for just - * optimization. Protected by zone->lock. - */ - int nr_migrate_reserve_block; - #ifdef CONFIG_MEMORY_ISOLATION /* * Number of isolated pageblock. It is used to solve incorrect diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 9812d46..dabd247 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -116,7 +116,7 @@ static void set_recommended_min_free_kbytes(void) for_each_populated_zone(zone) nr_zones++; - /* Make sure at least 2 hugepages are free for MIGRATE_RESERVE */ + /* Ensure 2 pageblocks are free to assist fragmentation avoidance */ recommended_min = pageblock_nr_pages * nr_zones * 2; /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8dc6e3c..5888126 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -817,7 +817,6 @@ static void free_pcppages_bulk(struct zone *zone, int count, if (unlikely(has_isolate_pageblock(zone))) mt = get_pageblock_migratetype(page); - /* MIGRATE_MOVABLE list may include MIGRATE_RESERVEs */ __free_one_page(page, page_to_pfn(page), zone, 0, mt); trace_mm_page_pcpu_drain(page, 0, mt); } while (--to_free && --batch_free && !list_empty(list)); @@ -1417,15 +1416,14 @@ struct page *__rmqueue_smallest(struct zone *zone, unsigned int order, * the free lists for the desirable migrate type are depleted */ static int fallbacks[MIGRATE_TYPES][4] = { - [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, - [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_RESERVE }, - [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_RESERVE }, + [MIGRATE_UNMOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, + [MIGRATE_RECLAIMABLE] = { MIGRATE_UNMOVABLE, MIGRATE_MOVABLE, MIGRATE_TYPES }, + [MIGRATE_MOVABLE] = { MIGRATE_RECLAIMABLE, MIGRATE_UNMOVABLE, MIGRATE_TYPES }, #ifdef CONFIG_CMA - [MIGRATE_CMA] = { MIGRATE_RESERVE }, /* Never used */ + [MIGRATE_CMA] = { MIGRATE_TYPES }, /* Never used */ #endif - [MIGRATE_RESERVE] = { MIGRATE_RESERVE }, /* Never used */ #ifdef CONFIG_MEMORY_ISOLATION - [MIGRATE_ISOLATE] = { MIGRATE_RESERVE }, /* Never used */ + [MIGRATE_ISOLATE] = { MIGRATE_TYPES }, /* Never used */ #endif }; @@ -1598,7 +1596,7 @@ int find_suitable_fallback(struct free_area *area, unsigned int order, *can_steal = false; for (i = 0;; i++) { fallback_mt = fallbacks[migratetype][i]; - if (fallback_mt == MIGRATE_RESERVE) + if (fallback_mt == MIGRATE_TYPES) break; if (list_empty(&area->free_list[fallback_mt])) @@ -1676,25 +1674,13 @@ static struct page *__rmqueue(struct zone *zone, unsigned int order, { struct page *page; -retry_reserve: page = __rmqueue_smallest(zone, order, migratetype); - - if (unlikely(!page) && migratetype != MIGRATE_RESERVE) { + if (unlikely(!page)) { if (migratetype == MIGRATE_MOVABLE) page = __rmqueue_cma_fallback(zone, order); if (!page) page = __rmqueue_fallback(zone, order, migratetype); - - /* - * Use MIGRATE_RESERVE rather than fail an allocation. goto - * is used because __rmqueue_smallest is an inline function - * and we want just one call site - */ - if (!page) { - migratetype = MIGRATE_RESERVE; - goto retry_reserve; - } } trace_mm_page_alloc_zone_locked(page, order, migratetype); @@ -3492,7 +3478,6 @@ static void show_migration_types(unsigned char type) [MIGRATE_UNMOVABLE] = 'U', [MIGRATE_RECLAIMABLE] = 'E', [MIGRATE_MOVABLE] = 'M', - [MIGRATE_RESERVE] = 'R', #ifdef CONFIG_CMA [MIGRATE_CMA] = 'C', #endif @@ -4303,120 +4288,6 @@ static inline unsigned long wait_table_bits(unsigned long size) } /* - * Check if a pageblock contains reserved pages - */ -static int pageblock_is_reserved(unsigned long start_pfn, unsigned long end_pfn) -{ - unsigned long pfn; - - for (pfn = start_pfn; pfn < end_pfn; pfn++) { - if (!pfn_valid_within(pfn) || PageReserved(pfn_to_page(pfn))) - return 1; - } - return 0; -} - -/* - * Mark a number of pageblocks as MIGRATE_RESERVE. The number - * of blocks reserved is based on min_wmark_pages(zone). The memory within - * the reserve will tend to store contiguous free pages. Setting min_free_kbytes - * higher will lead to a bigger reserve which will get freed as contiguous - * blocks as reclaim kicks in - */ -static void setup_zone_migrate_reserve(struct zone *zone) -{ - unsigned long start_pfn, pfn, end_pfn, block_end_pfn; - struct page *page; - unsigned long block_migratetype; - int reserve; - int old_reserve; - - /* - * Get the start pfn, end pfn and the number of blocks to reserve - * We have to be careful to be aligned to pageblock_nr_pages to - * make sure that we always check pfn_valid for the first page in - * the block. - */ - start_pfn = zone->zone_start_pfn; - end_pfn = zone_end_pfn(zone); - start_pfn = roundup(start_pfn, pageblock_nr_pages); - reserve = roundup(min_wmark_pages(zone), pageblock_nr_pages) >> - pageblock_order; - - /* - * Reserve blocks are generally in place to help high-order atomic - * allocations that are short-lived. A min_free_kbytes value that - * would result in more than 2 reserve blocks for atomic allocations - * is assumed to be in place to help anti-fragmentation for the - * future allocation of hugepages at runtime. - */ - reserve = min(2, reserve); - old_reserve = zone->nr_migrate_reserve_block; - - /* When memory hot-add, we almost always need to do nothing */ - if (reserve == old_reserve) - return; - zone->nr_migrate_reserve_block = reserve; - - for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages) { - if (!early_page_nid_uninitialised(pfn, zone_to_nid(zone))) - return; - - if (!pfn_valid(pfn)) - continue; - page = pfn_to_page(pfn); - - /* Watch out for overlapping nodes */ - if (page_to_nid(page) != zone_to_nid(zone)) - continue; - - block_migratetype = get_pageblock_migratetype(page); - - /* Only test what is necessary when the reserves are not met */ - if (reserve > 0) { - /* - * Blocks with reserved pages will never free, skip - * them. - */ - block_end_pfn = min(pfn + pageblock_nr_pages, end_pfn); - if (pageblock_is_reserved(pfn, block_end_pfn)) - continue; - - /* If this block is reserved, account for it */ - if (block_migratetype == MIGRATE_RESERVE) { - reserve--; - continue; - } - - /* Suitable for reserving if this block is movable */ - if (block_migratetype == MIGRATE_MOVABLE) { - set_pageblock_migratetype(page, - MIGRATE_RESERVE); - move_freepages_block(zone, page, - MIGRATE_RESERVE); - reserve--; - continue; - } - } else if (!old_reserve) { - /* - * At boot time we don't need to scan the whole zone - * for turning off MIGRATE_RESERVE. - */ - break; - } - - /* - * If the reserve is met and this is a previous reserved block, - * take it back - */ - if (block_migratetype == MIGRATE_RESERVE) { - set_pageblock_migratetype(page, MIGRATE_MOVABLE); - move_freepages_block(zone, page, MIGRATE_MOVABLE); - } - } -} - -/* * Initially all pages are reserved - free ones are freed * up by free_all_bootmem() once the early boot process is * done. Non-atomic initialization, single-pass. @@ -4455,9 +4326,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, * movable at startup. This will force kernel allocations * to reserve their blocks rather than leaking throughout * the address space during boot when many long-lived - * kernel allocations are made. Later some blocks near - * the start are marked MIGRATE_RESERVE by - * setup_zone_migrate_reserve() + * kernel allocations are made. * * bitmap is created for zone's valid pfn range. but memmap * can be created for invalid pages (for alignment) @@ -6018,7 +5887,6 @@ static void __setup_per_zone_wmarks(void) high_wmark_pages(zone) - low_wmark_pages(zone) - atomic_long_read(&zone->vm_stat[NR_ALLOC_BATCH])); - setup_zone_migrate_reserve(zone); spin_unlock_irqrestore(&zone->lock, flags); } diff --git a/mm/vmstat.c b/mm/vmstat.c index ffcb4f5..5b289dc 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -923,7 +923,6 @@ static char * const migratetype_names[MIGRATE_TYPES] = { "Unmovable", "Reclaimable", "Movable", - "Reserve", #ifdef CONFIG_CMA "CMA", #endif diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 8ed2ffd963c5..7340353f8aea 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -957,8 +957,9 @@ EXPORT_SYMBOL(congestion_wait); * jiffies for either a BDI to exit congestion of the given @sync queue * or a write to complete. * - * In the absence of zone congestion, cond_resched() is called to yield - * the processor if necessary but otherwise does not sleep. + * In the absence of zone congestion, a short sleep or a cond_resched is + * performed to yield the processor and to allow other subsystems to make + * a forward progress. * * The return value is 0 if the sleep is for the full timeout. Otherwise, * it is the number of jiffies that were still remaining when the function @@ -978,7 +979,19 @@ long wait_iff_congested(struct zone *zone, int sync, long timeout) */ if (atomic_read(&nr_wb_congested[sync]) == 0 || !test_bit(ZONE_CONGESTED, &zone->flags)) { - cond_resched(); + + /* + * Memory allocation/reclaim might be called from a WQ + * context and the current implementation of the WQ + * concurrency control doesn't recognize that a particular + * WQ is congested if the worker thread is looping without + * ever sleeping. Therefore we have to do a short sleep + * here rather than calling cond_resched(). + */ + if (current->flags & PF_WQ_WORKER) + schedule_timeout(1); + else + cond_resched(); /* In case we scheduled, work out time remaining */ ret = timeout - (jiffies - start); diff --git a/mm/vmstat.c b/mm/vmstat.c index 45dcbcb5c594..0975da8e3432 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1381,6 +1381,7 @@ static const struct file_operations proc_vmstat_file_operations = { #endif /* CONFIG_PROC_FS */ #ifdef CONFIG_SMP +static struct workqueue_struct *vmstat_wq; static DEFINE_PER_CPU(struct delayed_work, vmstat_work); int sysctl_stat_interval __read_mostly = HZ; static cpumask_var_t cpu_stat_off; @@ -1393,7 +1394,7 @@ static void vmstat_update(struct work_struct *w) * to occur in the future. Keep on running the * update worker thread. */ - schedule_delayed_work_on(smp_processor_id(), + queue_delayed_work_on(smp_processor_id(), vmstat_wq, this_cpu_ptr(&vmstat_work), round_jiffies_relative(sysctl_stat_interval)); } else { @@ -1462,7 +1463,7 @@ static void vmstat_shepherd(struct work_struct *w) if (need_update(cpu) && cpumask_test_and_clear_cpu(cpu, cpu_stat_off)) - schedule_delayed_work_on(cpu, + queue_delayed_work_on(cpu, vmstat_wq, &per_cpu(vmstat_work, cpu), 0); put_online_cpus(); @@ -1551,6 +1552,7 @@ static int __init setup_vmstat(void) start_shepherd_timer(); cpu_notifier_register_done(); + vmstat_wq = alloc_workqueue("vmstat", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0); #endif #ifdef CONFIG_PROC_FS proc_create("buddyinfo", S_IRUGO, NULL, &fragmentation_file_operations); -- 2.6.2