From mboxrd@z Thu Jan 1 00:00:00 1970 From: grygorii.strashko@ti.com (Grygorii Strashko) Date: Tue, 18 Mar 2014 17:01:59 +0200 Subject: [linux-next][regression] [PATCH] percpu: add preemption checks to __this_cpu ops Message-ID: <53285FE7.5010203@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi All, The regression is observed in the current linux-next on ARM Keystone 2 SoC: - system is booted till console and in a second or two and then stall, no messages displayed (CONFIG_DEBUG_PREEMPT=y). The cause of regression has been bisected to the commit: commit 589a606f9539663f162e4a110d117527833b58a4 Author: Christoph Lameter Date: Mon Mar 17 11:27:41 2014 +1100 percpu: add preemption checks to __this_cpu ops We define a check function in order to avoid trouble with the include files. Then the higher level __this_cpu macros are modified to invoke the preemption check. Signed-off-by: Christoph Lameter Acked-by: Ingo Molnar Cc: Tejun Heo Signed-off-by: Andrew Morton [=== 1 ===] If above patch is reverted - system can boot again. [=== 2 ===] If I apply below change - system can boot again. diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c index a270dce..73a2004 100644 --- a/lib/smp_processor_id.c +++ b/lib/smp_processor_id.c @@ -58,9 +58,6 @@ EXPORT_SYMBOL(debug_smp_processor_id); notrace void __this_cpu_preempt_check(const char *op) { - char text[40]; - - snprintf(text, sizeof(text), "__this_cpu_%s()", op); - check_preemption_disabled(text); + check_preemption_disabled(op); } EXPORT_SYMBOL(__this_cpu_preempt_check); linux-next top commits: 3bd688c Add linux-next specific files for 20140318 9a63a74 Merge branch 'akpm/master' ccdf335 mm: add strictlimit knob 589a606 percpu: add preemption checks to __this_cpu ops cdbd87c net: replace __this_cpu_inc in route.c with raw_cpu_inc 049fcfe modules: use raw_cpu_write for initialization of per cpu refcount. b46b094 mm: use raw_cpu ops for determining current NUMA node d934df8 percpu: add raw_cpu_ops c4a8790 arm: move arm_dma_limit to setup_dma_zone Regards, -grygorii