From: Jens Axboe <axboe@xxxxxxxxx> Sent: Tuesday, January 24, 2023 8:13 AM > > On 1/24/23 9:03 AM, Michael Kelley (LINUX) wrote: > > From: Jens Axboe <axboe@xxxxxxxxx> Sent: Saturday, January 21, 2023 1:11 PM > >> > >> On 1/20/23 9:56?PM, Michael Kelley (LINUX) wrote: > >>> From: Jens Axboe <axboe@xxxxxxxxx> Sent: Monday, January 16, 2023 1:06 PM > > > > [snip] > > > >>> > >>> I've wrapped up my testing on this patch. All testing was via > >>> io_uring -- I did not test other paths. Testing was against a > >>> combination of this patch and the previous patch set for a similar > >>> problem. [1] > >>> > >>> I tested with a simple test program to issue single I/Os, and verified > >>> the expected paths were taken through the block layer and io_uring > >>> code for various size I/Os, including over 1 Mbyte. No EAGAIN errors > >>> were seen. This testing was with a 6.1 kernel. > >>> > >>> Also tested the original app that surfaced the problem. It's a larger > >>> scale workload using io_uring, and is where the problem was originally > >>> encountered. That workload runs on a purpose-built 5.15 kernel, so I > >>> backported both patches to 5.15 for this testing. All looks good. No > >>> EAGAIN errors were seen. > >> > >> Thanks a lot for your thorough testing! Can you share the 5.15 > >> backports, so we can put them into 5.15-stable as well potentially? > >> > > > > Certainly. What's the best way to do that? Should I send them to you, > > or to the linux-block list? Or post directly to stable@xxxxxxxxxxxxxxx? > > If the latter, maybe I need to wait until it has an upstream commit ID > > that can be referenced. Also, you or someone should do a quick review > > of the backport to make sure I didn't break something in a path I > > didn't test. > > Just send them to the block list, then we have them for when the commit > hits upstream and gives us a chance to review them upfront. > > Thanks! > Your first two patches for handling bio splitting have already been backported to 5.15 and are included in 5.15.90. However, in reviewing the backports, stable commit 613b14884b85 didn't update dm_submit_bio() to check for a NULL bio being returned by blk_queue_split(). Presumably that needs to be fixed unless there is a reason the check isn't needed (which I didn't see). Separately, I've posted a v5.15.90 backport for the __blkdev_direct_IO() fix for multiple bio's. Michael
