- 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
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