On Wed, 26 Nov 2014 10:02:23 -0500, Chris Mason wrote: > On Wed, Nov 26, 2014 at 8:04 AM, Miao Xie <miaox@xxxxxxxxxxxxxx> wrote: >> The increase/decrease of bio counter is on the I/O path, so we should >> use io_schedule() instead of schedule(), or the deadlock might be >> triggered by the pending I/O in the plug list. io_schedule() can help >> us because it will flush all the pending I/O before the task is going >> to sleep. > > Can you please describe this deadlock in more detail? schedule() also triggers > a flush of the plug list, and if that's no longer sufficient we can run into other > problems (especially with preemption on). Sorry for my miss. I forgot to check the current implementation of schedule(), which flushes the plug list unconditionally. Please ignore this patch. Thanks Miao > > -chris > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
