** Description changed: + === SRU Justification === + [Impact] + To get better performance for dm-crypt in some cases, bypass kcryptd workqueue can reduce the overhead in context switch between workers, cherry-pick commit 39d42fa96ba1b7d2544db3f8ed5da8fb0d5cb877 from mainline kernel, and this is not enabled by default + + [Fix] + Add flags to bypass kcryptd workqueue + + [Test] + create dm-crypt and setup DM_CRYPT_NO_READ_WORKQUEUE and DM_CRYPT_NO_WRITE_WORKQUEUE, read/write data and run perf record to see if read/write to the encrypted device will bypass kcryptd workqueue + + [Regression Potential] + Low, this feature is disabled by default, need to enable manually + + ========= original bug description ========= Hi, I'm asking if it would be possible to cherry-pick patch "dm crypt: add flags to optionally bypass kcryptd workqueues" into the 5.4 Ubuntu kernel. This patch has been merged in mainline kernel 5.9 https://github.com/torvalds/linux/commit/39d42fa96ba1b7d2544db3f8ed5da8fb0d5cb877 but was not tagged for the stable tree. This patch provides important performance gains for some workloads using dm-crypt / LUKS and cherry-picking it would be very beneficial for dm- crypt users. You can find details on the expected gain in the following links: * https://www.redhat.com/archives/dm-devel/2020-July/msg00138.html * https://blog.cloudflare.com/speeding-up-linux-disk-encryption/ The patch mostly applies cleanly on the Ubuntu 5.4 kernel, the only merge conflict is due to the module version at the end of the patch. I can provide a backport patch if needed. Thanks,
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1910976 Title: Cherry-pick dm-crypt performance improvement patch from Linux 5.9 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1910976/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
