From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 9ff6aa027dbb98755f0265695354f2dd07c0d1ce ] debug_dma_dump_mappings() can take a lot of cpu cycles : lpk43:/# time wc -l /sys/kernel/debug/dma-api/dump 163435 /sys/kernel/debug/dma-api/dump real 0m0.463s user 0m0.003s sys 0m0.459s Let's add a cond_resched() to avoid holding cpu for too long. Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Cc: Corentin Labbe <clabbe@xxxxxxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- lib/dma-debug.c | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 51a76af25c663..173013f5e41b9 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -427,6 +427,7 @@ void debug_dma_dump_mappings(struct device *dev) } spin_unlock_irqrestore(&bucket->lock, flags); + cond_resched(); } } EXPORT_SYMBOL(debug_dma_dump_mappings); -- 2.20.1
