2011-8-1 21:07:39

来源：互联网发布：淘宝买的东西靠谱不编辑：程序博客网时间：2024/04/30 04:16

2011-8-1 21:07:39

I get below warning:
BUG: using smp_processor_id() in preemptible [00000000] code: bash/739 caller is drain_local_stock+0x1a/0x55
Pid: 739, comm: bash Tainted: G W 3.0.0+ #255
Call Trace:
[<ffffffff813435c6>] debug_smp_processor_id+0xc2/0xdc [<ffffffff8114ae9b>] drain_local_stock+0x1a/0x55 [<ffffffff8114b076>] drain_all_stock+0x98/0x13a [<ffffffff8114f04c>] mem_cgroup_force_empty+0xa3/0x27a [<ffffffff8114ff1d>] ? sys_close+0x38/0x138 [<ffffffff811a7631>] ? environ_read+0x1d/0x159 [<ffffffff8114f253>] mem_cgroup_force_empty_write+0x17/0x19
[<ffffffff810c72fb>] cgroup_file_write+0xa8/0xba [<ffffffff811522ce>] vfs_write+0xb3/0x138 [<ffffffff81152416>] sys_write+0x4a/0x71 [<ffffffff8114ffd5>] ? sys_close+0xf0/0x138 [<ffffffff8176deab>] system_call_fastpath+0x16/0x1b

drain_local_stock() should be run with preempt disabled.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 5f84d23..11d5671 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2169,13 +2169,7 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)

  /* Notify other cpus that system-wide "drain" is running */
  get_online_cpus();
- /*
- * Get a hint for avoiding draining charges on the current cpu,
- * which must be exhausted by our charging. It is not required that
- * this be a precise check, so we use raw_smp_processor_id() instead of
- * getcpu()/putcpu().
- */
- curcpu = raw_smp_processor_id();
+ curcpu = get_cpu();
  for_each_online_cpu(cpu) {
   struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu);
   struct mem_cgroup *mem;
@@ -2192,6 +2186,7 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync)
     schedule_work_on(cpu, &stock->work);
   }
  }
+ put_cpu();

  if (!sync)
   goto out;