[PATCH 1/1] MM: slqb, fix per_cpu access

We cannot use the same local variable name as the declared per_cpu
variable since commit "percpu: remove per_cpu__ prefix."

Otherwise we would see crashes like:
general protection fault: 0000 [#1] SMP
last sysfs file:
CPU 1
Modules linked in:
Pid: 1, comm: swapper Tainted: G W 2.6.32-rc5-mm1_64 #860
RIP: 0010:[<ffffffff8142ff94>] [<ffffffff8142ff94>] start_cpu_timer+0x2b/0x87
....

Signed-off-by: Jiri Slaby <jirislaby.TakeThisOut@gmail.com>
Cc: Nick Piggin <npiggin.TakeThisOut@suse.de>
Cc: Tejun Heo <tj.TakeThisOut@kernel.org>
Cc: Rusty Russell <rusty.TakeThisOut@rustcorp.com.au>
Cc: Christoph Lameter <cl.TakeThisOut@linux-foundation.org>
---
mm/slqb.c | 8 ++++----
1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/slqb.c b/mm/slqb.c
index e745d9a..27f5025 100644
--- a/mm/slqb.c
+++ b/mm/slqb.c
@@ -2770,16 +2770,16 @@ static DEFINE_PER_CPU(struct delayed_work, cache_trim_work);

static void __cpuinit start_cpu_timer(int cpu)
{
- struct delayed_work *cache_trim_work = &per_cpu(cache_trim_work, cpu);
+ struct delayed_work *_cache_trim_work = &per_cpu(cache_trim_work, cpu);

/*
* When this gets called from do_initcalls via cpucache_init(),
* init_workqueues() has already run, so keventd will be setup
* at that time.
*/
- if (keventd_up() && cache_trim_work->work.func == NULL) {
- INIT_DELAYED_WORK(cache_trim_work, cache_trim_worker);
- schedule_delayed_work_on(cpu, cache_trim_work,
+ if (keventd_up() && _cache_trim_work->work.func == NULL) {
+ INIT_DELAYED_WORK(_cache_trim_work, cache_trim_worker);
+ schedule_delayed_work_on(cpu, _cache_trim_work,
__round_jiffies_relative(HZ, cpu));
}
}
--
1.6.4.2

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Hello,

Jiri Slaby wrote:
> @@ -2770,16 +2770,16 @@ static DEFINE_PER_CPU(struct delayed_work, cache_trim_work);

How about renaming cache_trim_work to slqb_cache_trim_work? Another
percpu name requirement is global uniqueness (for s390 and alpha
support), so prefixing perpcu variables with subsystem name usually
resolves situations like this better.

Thanks.

--
tejun
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