Hi Coly, is this the deadlock I reported some weeks ago? Greets, Stefan Excuse my typo sent from my mobile phone. Am 27.09.2018 um 17:53 schrieb Eddie Chapman <eddie@xxxxxxxx <mailto:eddie@xxxxxxxx>>: > On 27/09/18 16:23, Coly Li wrote: >> On 9/27/18 9:45 PM, guoju wrote: >>> After write SSD completed, bcache schedule journal_write work to >>> system_wq, that is a public workqueue in system, without WQ_MEM_RECLAIM >>> flag. system_wq is also a bound wq, and there may be no idle kworker on >>> current processor. Creating a new kworker may unfortunately need to >>> reclaim memory first, by shrinking cache and slab used by vfs, which >>> depends on bcache device. That's a deadlock. >>> >>> This patch create a new workqueue for journal_write with WQ_MEM_RECLAIM >>> flag. It's rescuer thread will work to avoid the deadlock. >>> >>> Signed-off-by: guoju <fangguoju@xxxxxxxxx <mailto:fangguoju@xxxxxxxxx>> >> Nice catch, this fix is quite important. I will try to submit to Jens >> ASAP. >> Thanks. >> Coly Li > > Once this goes into 4.19, would this be a candidate for backporting to > any stable kernels, or does it only fix something introduced in this > cycle? > > thanks, > Eddie
