https://bugzilla.kernel.org/show_bug.cgi?id=202349 Bug ID: 202349 Summary: Extreme desktop freezes during sustained write operations with XFS Product: File System Version: 2.5 Kernel Version: 4,19.16 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: XFS Assignee: filesystem_xfs@xxxxxxxxxxxxxxxxxxxxxx Reporter: nfxjfg@xxxxxxxxxxxxxx Regression: No If you keep appending data to a a file on a XFS filesystem, the entire system will occasionally freeze for up to 4 seconds or so. Then it recovers and continues for a few minutes, until it happens again. Although the freezes happen at sort of random times, it's generally highly reproducible. This is extremely bothersome for desktop use, as _everything_ stops during the freeze. Even typing text into a terminal. Even processes that don't appear to do any I/O are frozen (at least not I/O to disks). For example, a python script that does nothing else than printing a counter to stdout (running in a X11 terminal emulator) will stop. Everything is completely in memory; the system disk is on a SSD anyway. In general, the desktop becomes completely unusable garbage, which in turn makes XFS unsuitable for desktop operation until this is fixed. Reproduction is simple enough: if I copy multiple large files (dozens of files with about 500-5000 MB per file) with rsync from one disk to another (both hard disks using XFS filesystems), the freezes will happen at least every few minutes. Someone else observed something similar independently just now, and suspects this is happening because XFS blocks the entire kernel when freeing certain caches: https://twitter.com/marcan42/status/1086652425061056515 I don't know whether my case is the same, but it sure looks very similar. This is with kernel 4.19.16, deadline scheduler for both source and target (as recommended by XFS FAQ), and full kernel preemption enabled. The system has 16GB RAM, of which 10GB are usually available for caches. I don't know what information is useful, so please request whatever information might be useful for analyzing this. -- You are receiving this mail because: You are watching the assignee of the bug.
