From: Tim Chen Date: Wed, 19 Apr 2006 05:21:47 +0000 (-0700) Subject: [PATCH] Kconfig.debug: Set DEBUG_MUTEX to off by default X-Git-Tag: v2.6.17-rc3~103 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cca57c5b5ab164e3c96576fc7739c0a30c2eab72;p=linux-2.6 [PATCH] Kconfig.debug: Set DEBUG_MUTEX to off by default DEBUG_MUTEX flag is on by default in current kernel configuration. During performance testing, we saw mutex debug functions like mutex_debug_check_no_locks_freed (called by kfree()) is expensive as it goes through a global list of memory areas with mutex lock and do the checking. For benchmarks such as Volanomark and Hackbench, we have seen more than 40% drop in performance on some platforms. We suggest to set DEBUG_MUTEX off by default. Or at least do that later when we feel that the mutex changes in the current code have stabilized. Signed-off-by: Tim Chen Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d57fd9181b..6ecc180beb 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -101,7 +101,7 @@ config DEBUG_PREEMPT config DEBUG_MUTEXES bool "Mutex debugging, deadlock detection" - default y + default n depends on DEBUG_KERNEL help This allows mutex semantics violations and mutex related deadlocks