From 1ecd01d77c9bf5517617862d87b817804b67c771 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Tue, 10 May 2022 13:17:32 -0400 Subject: dma-debug: change allocation mode from GFP_NOWAIT to GFP_ATIOMIC [ 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 Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') 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) -- cgit v1.2.3 From d7be05aff27278c89c5c2d5518e235a315ce447a Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Wed, 1 Jun 2022 07:51:16 -0700 Subject: dma-debug: make things less spammy under memory pressure [ Upstream commit e19f8fa6ce1ca9b8b934ba7d2e8f34c95abc6e60 ] Limit the error msg to avoid flooding the console. If you have a lot of threads hitting this at once, they could have already gotten passed the dma_debug_disabled() check before they get to the point of allocation failure, resulting in quite a lot of this error message spamming the log. Use pr_err_once() to limit that. Signed-off-by: Rob Clark Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- kernel/dma/debug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/dma/debug.c') diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index ee7da1f2462f..ae9fc1ee6d20 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -564,7 +564,7 @@ static void add_dma_entry(struct dma_debug_entry *entry) rc = active_cacheline_insert(entry); if (rc == -ENOMEM) { - pr_err("cacheline tracking ENOMEM, dma-debug disabled\n"); + pr_err_once("cacheline tracking ENOMEM, dma-debug disabled\n"); global_disable = true; } -- cgit v1.2.3