Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx> writes: > On 4/12/21 6:27 PM, Huang, Ying wrote: > >> >> This isn't the commit that introduces the race. You can use `git blame` >> find out the correct commit. For this it's commit 0bcac06f27d7 "mm, >> swap: skip swapcache for swapin of synchronous device". >> >> And I suggest to merge 1/5 and 2/5 to make it easy to get the full >> picture. > > I'll suggest make fix to do_swap_page race with get/put_swap_device > as a first patch. Then the per_cpu_ref stuff in patch 1 and patch 2 can > be combined together. The original get/put_swap_device() use rcu_read_lock/unlock(). I don't think it's good to wrap swap_read_page() with it. After all, some complex operations are done in swap_read_page(), including blk_io_schedule(). Best Regards, Huang, Ying
