diff options
| author | Michal Hocko <mhocko@suse.com> | 2017-11-15 17:38:56 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-15 18:21:07 -0800 |
| commit | fcdaf842bd8f538a88059ce0243bc2822ed1b0e0 (patch) | |
| tree | e8f1739778b4f0e8d11b630482b55f197694c842 | |
| parent | fec11bc0396bbd82b152e6ce9a47483ffd69462a (diff) | |
mm, sparse: do not swamp log with huge vmemmap allocation failures
While doing memory hotplug tests under heavy memory pressure we have
noticed too many page allocation failures when allocating vmemmap memmap
backed by huge page
kworker/u3072:1: page allocation failure: order:9, mode:0x24084c0(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO)
[...]
Call Trace:
dump_trace+0x59/0x310
show_stack_log_lvl+0xea/0x170
show_stack+0x21/0x40
dump_stack+0x5c/0x7c
warn_alloc_failed+0xe2/0x150
__alloc_pages_nodemask+0x3ed/0xb20
alloc_pages_current+0x7f/0x100
vmemmap_alloc_block+0x79/0xb6
__vmemmap_alloc_block_buf+0x136/0x145
vmemmap_populate+0xd2/0x2b9
sparse_mem_map_populate+0x23/0x30
sparse_add_one_section+0x68/0x18e
__add_pages+0x10a/0x1d0
arch_add_memory+0x4a/0xc0
add_memory_resource+0x89/0x160
add_memory+0x6d/0xd0
acpi_memory_device_add+0x181/0x251
acpi_bus_attach+0xfd/0x19b
acpi_bus_scan+0x59/0x69
acpi_device_hotplug+0xd2/0x41f
acpi_hotplug_work_fn+0x1a/0x23
process_one_work+0x14e/0x410
worker_thread+0x116/0x490
kthread+0xbd/0xe0
ret_from_fork+0x3f/0x70
and we do see many of those because essentially every allocation fails
for each memory section. This is an excessive way to tell the user that
there is nothing to really worry about because we do have a fallback
mechanism to use base pages. The only downside might be a performance
degradation due to TLB pressure.
This patch changes vmemmap_alloc_block() to use __GFP_NOWARN and warn
explicitly once on the first allocation failure. This will reduce the
noise in the kernel log considerably, while we still have an indication
that a performance might be impacted.
[mhocko@kernel.org: forgot to git add the follow up fix]
Link: http://lkml.kernel.org/r/20171107090635.c27thtse2lchjgvb@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/20171106092228.31098-1-mhocko@kernel.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/x86/mm/init_64.c | 1 | ||||
| -rw-r--r-- | mm/sparse-vmemmap.c | 12 |
2 files changed, 10 insertions, 3 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index c3fc544b50d2..4a837289f2ad 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -1405,7 +1405,6 @@ static int __meminit vmemmap_populate_hugepages(unsigned long start, vmemmap_verify((pte_t *)pmd, node, addr, next); continue; } - pr_warn_once("vmemmap: falling back to regular page backing\n"); if (vmemmap_populate_basepages(addr, next, node)) return -ENOMEM; } diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c index 4e49762599c8..17acf01791fa 100644 --- a/mm/sparse-vmemmap.c +++ b/mm/sparse-vmemmap.c @@ -53,12 +53,20 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node) { /* If the main allocator is up use that, fallback to bootmem. */ if (slab_is_available()) { + gfp_t gfp_mask = GFP_KERNEL|__GFP_RETRY_MAYFAIL|__GFP_NOWARN; + int order = get_order(size); + static bool warned; struct page *page; - page = alloc_pages_node(node, GFP_KERNEL | __GFP_RETRY_MAYFAIL, - get_order(size)); + page = alloc_pages_node(node, gfp_mask, order); if (page) return page_address(page); + + if (!warned) { + warn_alloc(gfp_mask & ~__GFP_NOWARN, NULL, + "vmemmap alloc failure: order:%u", order); + warned = true; + } return NULL; } else return __earlyonly_bootmem_alloc(node, size, size, |