Hi Theodore and Ojaswin, On Mon, Jan 08, 2024 at 09:53:18PM -0500, Theodore Ts'o wrote: > > On Fri, 15 Dec 2023 16:49:49 +0530, Ojaswin Mujoo wrote: > > This patch intends to fix the recent bugzilla [1] report where the > > kworker flush thread seemed to be taking 100% CPU utilizationa and was > > slowing down the whole system. The backtrace indicated that we were > > stuck in mballoc allocation path. The issue was only seen kernel 6.5+ > > and when ext4 was mounted with -o stripe (or stripe option was > > implicitly added due us mkfs flags used). > > > > [...] > > Applied, thanks! I backported this patch to at least 6.6 and tested on our fleet of software RAID 0 NVME SSD nodes. This change worked very nicely for us. We're interested in backporting this to at least 6.6. I tried looking at xfstests, and didn't really see a good match (user error?) to validate the fix via that. So I'm a little unclear what the path forward here is. Although we experienced this issue in 6.1, I didn't backport to 6.1 and test to verify this also works there, however, setting stripe to 0 did in the 6.1 case. Best, Fred > > [1/1] ext4: fallback to complex scan if aligned scan doesn't work > commit: a26b6faf7f1c9c1ba6edb3fea9d1390201f2ed50 > > Best regards, > -- > Theodore Ts'o <tytso@xxxxxxx>
