On Sat, Jan 01, 2022 at 05:39:45PM +0000, Trond Myklebust wrote: ... > > Fair enough. As long as someone is working on a solution, then I'm > happy. Just a couple of things: > > Firstly, we've verified that the cond_resched() in the bio loop does > suffice to resolve the issue with XFS, which would tend to confirm what > you're saying above about the underlying issue being the ioend chain > length. > > Secondly, note that we've tested this issue with a variety of older > kernels, including 4.18.x, 5.1.x and 5.15.x, so please bear in mind > that it would be useful for any fix to be backward portable through the > stable mechanism. > I've sent a couple or so different variants of this in the past. The last I believe was here [1], but still never seemed to go anywhere (despite having reviews on the first couple patches). That one was essentially a sequence of adding a cond_resched() call in the iomap code to address the soft lockup warning followed by capping the ioend size for latency reasons. Brian [1] https://lore.kernel.org/linux-xfs/20210517171722.1266878-1-bfoster@xxxxxxxxxx/ > > Thanks, and Happy New Year! > > Trond > > -- > Trond Myklebust > Linux NFS client maintainer, Hammerspace > trond.myklebust@xxxxxxxxxxxxxxx > >
