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dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC

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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>
This commit is contained in:
Mikulas Patocka 2022-05-10 13:17:32 -04:00 committed by Greg Kroah-Hartman
parent a61583744e
commit 1ecd01d77c
1 changed files with 1 additions and 1 deletions
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2
kernel/dma/debug.c
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@ -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)