From: Christian Brauner Date: Mon, 15 Sep 2025 12:50:03 +0000 (+0200) Subject: Merge patch series "writeback: Avoid lockups when switching inodes" X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=9426414f0d42f824892ecd4dccfebf8987084a41;p=thirdparty%2Fkernel%2Fstable.git Merge patch series "writeback: Avoid lockups when switching inodes" Jan Kara says: This patch series addresses lockups reported by users when systemd unit reading lots of files from a filesystem mounted with lazytime mount option exits. See patch 3 for more details about the reproducer. There are two main issues why switching many inodes between wbs: 1) Multiple workers will be spawned to do the switching but they all contend on the same wb->list_lock making all the parallelism pointless and just wasting time. 2) Sorting of wb->b_dirty list by dirtied_time_when is inherently slow. Patches 1-3 address these problems, patch 4 adds a tracepoint for better observability of inode writeback switching. * patches from https://lore.kernel.org/20250912103522.2935-1-jack@suse.cz: writeback: Add tracepoint to track pending inode switches writeback: Avoid excessively long inode switching times writeback: Avoid softlockup when switching many inodes writeback: Avoid contention on wb->list_lock when switching inodes Signed-off-by: Christian Brauner --- 9426414f0d42f824892ecd4dccfebf8987084a41