From: Mikulas Patocka mpatocka@redhat.com
stable inclusion from stable-v5.10.121 commit 1ecd01d77c9bf5517617862d87b817804b67c771 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit 84bc4f1dbbbb5f8aa68706a96711dccb28b518e5 ]
We observed the error "cacheline tracking ENOMEM, dma-debug disabled" during a light system load (copying some files). The reason for this error is that the dma_active_cacheline radix tree uses GFP_NOWAIT allocation - so it can't access the emergency memory reserves and it fails as soon as anybody reaches the watermark.
This patch changes GFP_NOWAIT to GFP_ATOMIC, so that it can access the emergency memory reserves.
Signed-off-by: Mikulas Patocka mpatocka@redhat.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Acked-by: Xie XiuQi xiexiuqi@huawei.com --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index f8ae54679865..ee7da1f2462f 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -448,7 +448,7 @@ void debug_dma_dump_mappings(struct device *dev) * other hand, consumes a single dma_debug_entry, but inserts 'nents' * entries into the tree. */ -static RADIX_TREE(dma_active_cacheline, GFP_NOWAIT); +static RADIX_TREE(dma_active_cacheline, GFP_ATOMIC); static DEFINE_SPINLOCK(radix_lock); #define ACTIVE_CACHELINE_MAX_OVERLAP ((1 << RADIX_TREE_MAX_TAGS) - 1) #define CACHELINE_PER_PAGE_SHIFT (PAGE_SHIFT - L1_CACHE_SHIFT)