| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 120/171] dma-debug: add a schedule point in debug_dma_dump_mappings() | Date | Thu, 2 Jan 2020 23:07:31 +0100 |
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From: Eric Dumazet <edumazet@google.com>
[ 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@google.com> Cc: Corentin Labbe <clabbe@baylibre.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org> --- lib/dma-debug.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c index 8971370bfb16..4435bec55fb5 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -435,6 +435,7 @@ 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
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