Messages in this thread Patch in this message | | | Date | Sun, 22 Jun 2008 09:40:18 +0200 | Subject | Re: [PATCH] x86/oprofile: disable preemption in nmi_shutdown | From | Vegard Nossum <> |
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Hi,
On Sun, Jun 22, 2008 at 9:30 AM, Johannes Weiner <hannes@saeurebad.de> wrote: > Vegard Nossum <vegard.nossum@gmail.com> writes: >> static void nmi_shutdown(void) >> { >> - struct op_msrs *msrs = &__get_cpu_var(cpu_msrs); >> + struct op_msrs *msrs; >> + >> + preempt_disable(); >> + msrs = &__get_cpu_var(cpu_msrs); >> nmi_enabled = 0; >> on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1); >> unregister_die_notifier(&profile_exceptions_nb); >> model->shutdown(msrs); >> free_msrs(); >> + preempt_enable(); > > Have a look at get_cpu_var() and put_cpu_var(), that is exactly the > pattern.
Thanks! How about this instead?
Vegard
From: Vegard Nossum <vegard.nossum@gmail.com> Date: Sat, 21 Jun 2008 23:44:19 +0200 Subject: [PATCH] x86/oprofile: disable preemption in nmi_shutdown
BUG: using smp_processor_id() in preemptible [00000000] code: oprofiled/27301 caller is nmi_shutdown+0x11/0x60 Pid: 27301, comm: oprofiled Not tainted 2.6.26-rc7 #25 [<c028a90d>] debug_smp_processor_id+0xbd/0xc0 [<c045fba1>] nmi_shutdown+0x11/0x60 [<c045dd4a>] oprofile_shutdown+0x2a/0x60
Note that we don't need this for the other functions, since they are all called with on_each_cpu() (which disables preemption for us anyway).
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com> --- arch/x86/oprofile/nmi_int.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c index cc48d3f..2b6ad5b 100644 --- a/arch/x86/oprofile/nmi_int.c +++ b/arch/x86/oprofile/nmi_int.c @@ -269,12 +269,13 @@ static void nmi_cpu_shutdown(void *dummy) static void nmi_shutdown(void) { - struct op_msrs *msrs = &__get_cpu_var(cpu_msrs); + struct op_msrs *msrs = &get_cpu_var(cpu_msrs); nmi_enabled = 0; on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1); unregister_die_notifier(&profile_exceptions_nb); model->shutdown(msrs); free_msrs(); + put_cpu_var(cpu_msrs); } static void nmi_cpu_start(void *dummy) -- 1.5.4.1
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