diff options
| -rw-r--r-- | Documentation/filesystems/nfs/nfsd-io-modes.rst | 28 |
1 files changed, 16 insertions, 12 deletions
diff --git a/Documentation/filesystems/nfs/nfsd-io-modes.rst b/Documentation/filesystems/nfs/nfsd-io-modes.rst index e3a522d09766..fa47c4d3dfb9 100644 --- a/Documentation/filesystems/nfs/nfsd-io-modes.rst +++ b/Documentation/filesystems/nfs/nfsd-io-modes.rst @@ -25,12 +25,14 @@ Based on the configured settings, NFSD's IO will either be: - not cached stable_how=NFS_UNSTABLE (NFSD_IO_DIRECT=2) To set an NFSD IO mode, write a supported value (0 - 2) to the -corresponding IO operation's debugfs interface, e.g.: +corresponding IO operation's debugfs interface, e.g.:: + echo 2 > /sys/kernel/debug/nfsd/io_cache_read echo 2 > /sys/kernel/debug/nfsd/io_cache_write To check which IO mode NFSD is using for READ or WRITE, simply read the -corresponding IO operation's debugfs interface, e.g.: +corresponding IO operation's debugfs interface, e.g.:: + cat /sys/kernel/debug/nfsd/io_cache_read cat /sys/kernel/debug/nfsd/io_cache_write @@ -128,17 +130,19 @@ Tracing: misaligned READ to the next DIO-aligned block (on either end of the original READ, as needed). - This combination of trace events is useful for READs: - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_vector/enable - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_direct/enable - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_io_done/enable - echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_read/enable + This combination of trace events is useful for READs:: + + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_vector/enable + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_direct/enable + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_io_done/enable + echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_read/enable The nfsd_write_direct trace event shows how NFSD splits a given misaligned WRITE into a DIO-aligned middle segment. - This combination of trace events is useful for WRITEs: - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_opened/enable - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_direct/enable - echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_io_done/enable - echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_write/enable + This combination of trace events is useful for WRITEs:: + + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_opened/enable + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_direct/enable + echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_io_done/enable + echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_write/enable |