While trying the new FS-Cache implementation using the 5.17-rc5 kernel on Ubuntu 21.10 I ran into an issue where it appears that FS-Cache was not being used when the sync mount option is enabled. While monitoring /proc/fs/fscache/stats it was observed there were high writes to the cache volume, but no reads: IO : rd=0 wr=344713665 Further tracing of /sys/kernel/debug/tracing/events/fscache/fscache_access shows a large number of io_write operations, but no io_read operations. The volume did fill up and perform culling as expected. When the mount option was changed from sync to async the cache performed as expected and a mixture of io_write and io_read was observed. -- Chris -- Linux-cachefs mailing list Linux-cachefs@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/linux-cachefs