On 12/3/20 2:25 PM, Yi Li wrote: >> On 12/1/20 12:35 PM, Yi Li wrote: >>> sorry, This patch will cause deadlock, i will check and redo it. >> >> Can you try latest upstream kernel firstly ? Before spending more time >> on the fix. >> > > This issue just happened three times （xenserver7.5 dom0 kernel） on the > same machine and cannot reproduce it now. and have not reproduce it > using the lastest uptream kernel. > Hmm, this is something very probably that I am not able to help. It seems the kernel is a third-part maintained Linux v4.4 based kernel + bcache backport, which is out of my view. If similar problem happens on latest upstream kernel, or at least v5.8+ kernel, I can help to take a look. >> If I remember correctly, when cancel_writeback_rate_update_dwork() is >> not timed out, the cache set memory won't be freed before the >> writeback_rate_update worker terminates. It is possible that I miss >> something in the code, but I suggest to test with a kernel after v5.3, >> and better a v5.8+ kernel. >> >> Coly Li >> > Thanks. > > it is confused that why writeback_rate_update worker run again after > cancel_delayed_work_sync( kernel log telled). > [snipped] Coly Li
