diff options
author | David Rientjes <rientjes@google.com> | 2013-04-30 00:06:11 +0200 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-04-30 00:54:28 +0200 |
commit | 4b59e6c4730978679b414a8da61514a2518da512 (patch) | |
tree | 241f48acea764191a458c6ae2d058b079b24f12d | |
parent | mm: trace filemap add and del (diff) | |
download | linux-4b59e6c4730978679b414a8da61514a2518da512.tar.xz linux-4b59e6c4730978679b414a8da61514a2518da512.zip |
mm, show_mem: suppress page counts in non-blockable contexts
On large systems with a lot of memory, walking all RAM to determine page
types may take a half second or even more.
In non-blockable contexts, the page allocator will emit a page allocation
failure warning unless __GFP_NOWARN is specified. In such contexts, irqs
are typically disabled and such a lengthy delay may even result in NMI
watchdog timeouts.
To fix this, suppress the page walk in such contexts when printing the
page allocation failure warning.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | arch/arm/mm/init.c | 3 | ||||
-rw-r--r-- | arch/ia64/mm/contig.c | 2 | ||||
-rw-r--r-- | arch/ia64/mm/discontig.c | 2 | ||||
-rw-r--r-- | arch/parisc/mm/init.c | 2 | ||||
-rw-r--r-- | arch/unicore32/mm/init.c | 3 | ||||
-rw-r--r-- | include/linux/mm.h | 3 | ||||
-rw-r--r-- | lib/show_mem.c | 3 | ||||
-rw-r--r-- | mm/page_alloc.c | 7 |
8 files changed, 24 insertions, 1 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index ad722f1208a5..ad9a9f3f0322 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -99,6 +99,9 @@ void show_mem(unsigned int filter) printk("Mem-info:\n"); show_free_areas(filter); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; + for_each_bank (i, mi) { struct membank *bank = &mi->bank[i]; unsigned int pfn1, pfn2; diff --git a/arch/ia64/mm/contig.c b/arch/ia64/mm/contig.c index 80dab509dfb0..67c59ebec899 100644 --- a/arch/ia64/mm/contig.c +++ b/arch/ia64/mm/contig.c @@ -47,6 +47,8 @@ void show_mem(unsigned int filter) printk(KERN_INFO "Mem-info:\n"); show_free_areas(filter); printk(KERN_INFO "Node memory in pages:\n"); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; for_each_online_pgdat(pgdat) { unsigned long present; unsigned long flags; diff --git a/arch/ia64/mm/discontig.c b/arch/ia64/mm/discontig.c index c2e955ee79a8..a57436e5d405 100644 --- a/arch/ia64/mm/discontig.c +++ b/arch/ia64/mm/discontig.c @@ -623,6 +623,8 @@ void show_mem(unsigned int filter) printk(KERN_INFO "Mem-info:\n"); show_free_areas(filter); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; printk(KERN_INFO "Node memory in pages:\n"); for_each_online_pgdat(pgdat) { unsigned long present; diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c index 3ac462de53a4..cf2da13c41e6 100644 --- a/arch/parisc/mm/init.c +++ b/arch/parisc/mm/init.c @@ -697,6 +697,8 @@ void show_mem(unsigned int filter) printk(KERN_INFO "Mem-info:\n"); show_free_areas(filter); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; #ifndef CONFIG_DISCONTIGMEM i = max_mapnr; while (i-- > 0) { diff --git a/arch/unicore32/mm/init.c b/arch/unicore32/mm/init.c index de186bde8975..644482882bae 100644 --- a/arch/unicore32/mm/init.c +++ b/arch/unicore32/mm/init.c @@ -66,6 +66,9 @@ void show_mem(unsigned int filter) printk(KERN_DEFAULT "Mem-info:\n"); show_free_areas(filter); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; + for_each_bank(i, mi) { struct membank *bank = &mi->bank[i]; unsigned int pfn1, pfn2; diff --git a/include/linux/mm.h b/include/linux/mm.h index e2091b88d24c..f3c7b1f9d1d8 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -899,7 +899,8 @@ extern void pagefault_out_of_memory(void); * Flags passed to show_mem() and show_free_areas() to suppress output in * various contexts. */ -#define SHOW_MEM_FILTER_NODES (0x0001u) /* filter disallowed nodes */ +#define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */ +#define SHOW_MEM_FILTER_PAGE_COUNT (0x0002u) /* page type count */ extern void show_free_areas(unsigned int flags); extern bool skip_free_areas_node(unsigned int flags, int nid); diff --git a/lib/show_mem.c b/lib/show_mem.c index 4407f8c9b1f7..b7c72311ad0c 100644 --- a/lib/show_mem.c +++ b/lib/show_mem.c @@ -18,6 +18,9 @@ void show_mem(unsigned int filter) printk("Mem-Info:\n"); show_free_areas(filter); + if (filter & SHOW_MEM_FILTER_PAGE_COUNT) + return; + for_each_online_pgdat(pgdat) { unsigned long i, flags; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7ff1536f01b8..da7a2fe7332e 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2003,6 +2003,13 @@ void warn_alloc_failed(gfp_t gfp_mask, int order, const char *fmt, ...) return; /* + * Walking all memory to count page types is very expensive and should + * be inhibited in non-blockable contexts. + */ + if (!(gfp_mask & __GFP_WAIT)) + filter |= SHOW_MEM_FILTER_PAGE_COUNT; + + /* * This documents exceptions given to allocations in certain * contexts that are allowed to allocate outside current's set * of allowed nodes. |