[PATCH v2] iommu/iova: silence warnings under memory pressure
From: Qian Cai
Date: Thu Nov 21 2019 - 21:55:27 EST
When running heavy memory pressure workloads, this 5+ old system is
throwing endless warnings below because disk IO is too slow to recover
from swapping. Since the volume from alloc_iova_fast() could be large,
once it calls printk(), it will trigger disk IO (writing to the log
files) and pending softirqs which could cause an infinite loop and make
no progress for days by the ongoimng memory reclaim. This is the counter
part for Intel where the AMD part has already been merged. See the
commit 3d708895325b ("iommu/amd: Silence warnings under memory
pressure"). Since the allocation failure will be reported in
intel_alloc_iova(), so just call printk_ratelimted() there and silence
the one in alloc_iova_mem() to avoid the expensive warn_alloc().
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
slab_out_of_memory: 66 callbacks suppressed
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
node 0: slabs: 1822, objs: 16398, free: 0
node 1: slabs: 2051, objs: 18459, free: 31
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
node 0: slabs: 1822, objs: 16398, free: 0
node 1: slabs: 2051, objs: 18459, free: 31
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
cache: iommu_iova, object size: 40, buffer size: 448, default order:
0, min order: 0
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
node 0: slabs: 697, objs: 4182, free: 0
node 0: slabs: 697, objs: 4182, free: 0
node 0: slabs: 697, objs: 4182, free: 0
node 0: slabs: 697, objs: 4182, free: 0
node 1: slabs: 381, objs: 2286, free: 27
node 1: slabs: 381, objs: 2286, free: 27
node 1: slabs: 381, objs: 2286, free: 27
node 1: slabs: 381, objs: 2286, free: 27
node 0: slabs: 1822, objs: 16398, free: 0
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
node 1: slabs: 2051, objs: 18459, free: 31
node 0: slabs: 697, objs: 4182, free: 0
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
node 1: slabs: 381, objs: 2286, free: 27
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
node 0: slabs: 697, objs: 4182, free: 0
node 1: slabs: 381, objs: 2286, free: 27
hpsa 0000:03:00.0: DMAR: Allocating 1-page iova failed
warn_alloc: 96 callbacks suppressed
kworker/11:1H: page allocation failure: order:0,
mode:0xa20(GFP_ATOMIC), nodemask=(null),cpuset=/,mems_allowed=0-1
CPU: 11 PID: 1642 Comm: kworker/11:1H Tainted: G B
Hardware name: HP ProLiant XL420 Gen9/ProLiant XL420 Gen9, BIOS U19
12/27/2015
Workqueue: kblockd blk_mq_run_work_fn
Call Trace:
dump_stack+0xa0/0xea
warn_alloc.cold.94+0x8a/0x12d
__alloc_pages_slowpath+0x1750/0x1870
__alloc_pages_nodemask+0x58a/0x710
alloc_pages_current+0x9c/0x110
alloc_slab_page+0xc9/0x760
allocate_slab+0x48f/0x5d0
new_slab+0x46/0x70
___slab_alloc+0x4ab/0x7b0
__slab_alloc+0x43/0x70
kmem_cache_alloc+0x2dd/0x450
SLUB: Unable to allocate memory on node -1, gfp=0xa20(GFP_ATOMIC)
alloc_iova+0x33/0x210
cache: skbuff_head_cache, object size: 208, buffer size: 640, default
order: 0, min order: 0
node 0: slabs: 697, objs: 4182, free: 0
alloc_iova_fast+0x62/0x3d1
node 1: slabs: 381, objs: 2286, free: 27
intel_alloc_iova+0xce/0xe0
intel_map_sg+0xed/0x410
scsi_dma_map+0xd7/0x160
scsi_queue_rq+0xbf7/0x1310
blk_mq_dispatch_rq_list+0x4d9/0xbc0
blk_mq_sched_dispatch_requests+0x24a/0x300
__blk_mq_run_hw_queue+0x156/0x230
blk_mq_run_work_fn+0x3b/0x40
process_one_work+0x579/0xb90
worker_thread+0x63/0x5b0
kthread+0x1e6/0x210
ret_from_fork+0x3a/0x50
Mem-Info:
active_anon:2422723 inactive_anon:361971 isolated_anon:34403
active_file:2285 inactive_file:1838 isolated_file:0
unevictable:0 dirty:1 writeback:5 unstable:0
slab_reclaimable:13972 slab_unreclaimable:453879
mapped:2380 shmem:154 pagetables:6948 bounce:0
free:19133 free_pcp:7363 free_cma:0
Signed-off-by: Qian Cai <cai@xxxxxx>
---
v2: use dev_err_ratelimited() and improve the commit messages.
drivers/iommu/intel-iommu.c | 3 ++-
drivers/iommu/iova.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 6db6d969e31c..c01a7bc99385 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3401,7 +3401,8 @@ static unsigned long intel_alloc_iova(struct device *dev,
iova_pfn = alloc_iova_fast(&domain->iovad, nrpages,
IOVA_PFN(dma_mask), true);
if (unlikely(!iova_pfn)) {
- dev_err(dev, "Allocating %ld-page iova failed", nrpages);
+ dev_err_ratelimited(dev, "Allocating %ld-page iova failed",
+ nrpages);
return 0;
}
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 41c605b0058f..aa1a56aaa5ee 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -233,7 +233,7 @@ static DEFINE_MUTEX(iova_cache_mutex);
struct iova *alloc_iova_mem(void)
{
- return kmem_cache_alloc(iova_cache, GFP_ATOMIC);
+ return kmem_cache_alloc(iova_cache, GFP_ATOMIC | __GFP_NOWARN);
}
EXPORT_SYMBOL(alloc_iova_mem);
--
2.21.0 (Apple Git-122.2)