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@xxxxxxxxxxxxxxxxxxx> --- arch/arm/configs/omap2plus_defconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig index 6491419..1bbfd76 100644 --- a/arch/arm/configs/omap2plus_defconfig +++ b/arch/arm/configs/omap2plus_defconfig @@ -536,7 +536,6 @@ CONFIG_DEBUG_INFO_SPLIT=y CONFIG_DEBUG_INFO_DWARF4=y CONFIG_MAGIC_SYSRQ=y CONFIG_SCHEDSTATS=y -CONFIG_PROVE_LOCKING=y # CONFIG_DEBUG_BUGVERBOSE is not set CONFIG_SECURITY=y CONFIG_CRYPTO_MICHAEL_MIC=y -- 2.7.4
