Messages in this thread Patch in this message | | | From | Lukasz Luba <> | Subject | [PATCH] config: arm: mxs: remove PROVE_LOCKING from defconfig | Date | Tue, 9 Oct 2018 17:37:31 +0200 |
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PROVE_LOCKING enables LOCKDEP, which causes big overhead on cache and bus transactions.
On some ARM big.LITTLE architecutres (Exynos 5433) the overhead is really big. The overhead can be measures using hackbench which will speed up by x3 times (11sec -> 3.4sec). When you check transaction on cache or buses, the results are way higher than normal for the same hackbench test: L1d cache invalidations: 26mln vs 4mln L2u cache invalidations: 42mln vs 12mln bus cyc/access: 30cyc/access vs. 20cyc/access context switch is x3 times cheaper
Enable this option only when you have some locking issue to investigate.
Signed-off-by: Lukasz Luba <l.luba@partner.samsung.com> --- arch/arm/configs/mxs_defconfig | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/arm/configs/mxs_defconfig b/arch/arm/configs/mxs_defconfig index 7b82128..22c9a8d 100644 --- a/arch/arm/configs/mxs_defconfig +++ b/arch/arm/configs/mxs_defconfig @@ -170,7 +170,6 @@ CONFIG_UNUSED_SYMBOLS=y CONFIG_MAGIC_SYSRQ=y CONFIG_DEBUG_KERNEL=y CONFIG_SOFTLOCKUP_DETECTOR=y -CONFIG_PROVE_LOCKING=y CONFIG_BLK_DEV_IO_TRACE=y CONFIG_STRICT_DEVMEM=y CONFIG_DEBUG_USER=y -- 2.7.4
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