On 11/27/24 3:33 PM, Christoph Hellwig wrote: > On Wed, Nov 27, 2024 at 03:32:04PM +0900, Damien Le Moal wrote: >> Might be good enough. But will also need to clear the REQ_NOWAIT flag for the >> BIO if it is issued from the zone write plug BIO work. Because that one should >> not have to deal with all this. > > Yes, by that time there is no point in the nowait. > > Another simpler option would be to always use the zone write plug BIO > work to issue NOWAIT bios. I thought about that one. The problem with it is the significant performance penalty that the context switch to the zone write plug BIO work causes. But that is for qd=1 writes only... If that is acceptable, that solution is actually the easiest. The overhead is not an issue for HDDs and for ZNS SSDs, zone append to the rescue ! So maybe for now, it is best to just do that. -- Damien Le Moal Western Digital Research