Lines Matching +full:write +full:- +full:enable

1 .. SPDX-License-Identifier: GPL-2.0
11 WRITE operations. BUFFERED is NFSD's default IO mode, but it is possible
15 mode used for READ and WRITE to be configured independently. See both:
17 - /sys/kernel/debug/nfsd/io_cache_read
18 - /sys/kernel/debug/nfsd/io_cache_write
25 - cached using page cache (NFSD_IO_BUFFERED=0)
26 - cached but removed from page cache on completion (NFSD_IO_DONTCACHE=1)
27 - not cached stable_how=NFS_UNSTABLE (NFSD_IO_DIRECT=2)
29 To set an NFSD IO mode, write a supported value (0 - 2) to the
35 To check which IO mode NFSD is using for READ or WRITE, simply read the
42 interesting results, please report them to linux-nfs@vger.kernel.org
56 read until much later). Such use-cases are particularly problematic
62 - Overview:  9ad6344568cc3 ("mm/filemap: change filemap_create_folio()
64 - for READ:  8026e49bff9b1 ("mm/filemap: add read support for
66 - for WRITE: 974c5e6139db3 ("xfs: flag as supporting FOP_DONTCACHE")
80 system memory. The pathological worst-case workload that NFSD DIRECT has
82 that is 2-3 times larger than the NFS server's available system memory.
91 discussed on linux-nfs, see:
92 https://lore.kernel.org/linux-nfs/aEslwqa9iMeZjjlV@kernel.org/
96 - NFSD DIRECT can significantly reduce memory requirements
97 - NFSD DIRECT can reduce CPU load by avoiding costly page reclaim work
98 - NFSD DIRECT can offer more deterministic IO performance
109 If NFSD_IO_DIRECT is specified by writing 2 (or 3 and 4 for WRITE) to
112 used to store the READ or WRITE payload must be aligned relative to the
120     DIO-aligned block (on either end of the READ). The expanded READ is
124 Misaligned WRITE:
125     If NFSD_IO_DIRECT is used, split any misaligned WRITE into a start,
126     middle and end as needed. The large middle segment is DIO-aligned
128     misaligned segments and O_DIRECT is used for the middle DIO-aligned
135     misaligned READ to the next DIO-aligned block (on either end of the
140       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_vector/enable
141       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_direct/enable
142       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_read_io_done/enable
143       echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_read/enable
146     misaligned WRITE into a DIO-aligned middle segment.
150       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_opened/enable
151       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_direct/enable
152       echo 1 > /sys/kernel/tracing/events/nfsd/nfsd_write_io_done/enable
153       echo 1 > /sys/kernel/tracing/events/xfs/xfs_file_direct_write/enable