mirror_zfs/lib
Alexander Motin 734eba251d
Wire O_DIRECT also to Uncached I/O (#17218)
Before Direct I/O was implemented, I've implemented lighter version
I called Uncached I/O.  It uses normal DMU/ARC data path with some
optimizations, but evicts data from caches as soon as possible and
reasonable.  Originally I wired it only to a primarycache property,
but now completing the integration all the way up to the VFS.

While Direct I/O has the lowest possible memory bandwidth usage,
it also has a significant number of limitations.  It require I/Os
to be page aligned, does not allow speculative prefetch, etc.  The
Uncached I/O does not have those limitations, but instead require
additional memory copy, though still one less than regular cached
I/O.  As such it should fill the gap in between.  Considering this
I've disabled annoying EINVAL errors on misaligned requests, adding
a tunable for those who wants to test their applications.

To pass the information between the layers I had to change a number
of APIs.  But as side effect upper layers can now control not only
the caching, but also speculative prefetch.  I haven't wired it to
VFS yet, since it require looking on some OS specifics.  But while
there I've implemented speculative prefetch of indirect blocks for
Direct I/O, controllable via all the same mechanisms.

Signed-off-by:	Alexander Motin <mav@FreeBSD.org>
Sponsored by:	iXsystems, Inc.
Fixes #17027
Reviewed-by: Rob Norris <robn@despairlabs.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
2025-05-13 14:26:55 -07:00
..
libavl cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libefi SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
libicp icp: remove skein module 2024-05-31 15:13:39 -07:00
libnvpair nvlist: Add nvlist_snprintf() and zfs_dbgmsg_nvlist() 2025-04-18 09:22:16 -04:00
libshare SPDX: license tags: BSD-2-Clause 2025-03-13 17:56:46 -07:00
libspl Support using llvm-libunwind 2025-04-24 13:58:48 -04:00
libtpool SPDX: license tags: CDDL-1.0 2025-03-13 17:56:27 -07:00
libunicode module: unicode: remove unused uconv.c 2024-11-01 12:12:13 -07:00
libuutil nvlist: Add nvlist_snprintf() and zfs_dbgmsg_nvlist() 2025-04-18 09:22:16 -04:00
libzdb Provide macros for setting and getting blkptr birth times 2024-03-25 15:01:54 -07:00
libzfs Implement allocation size ranges and use for gang leaves (#17111) 2025-05-02 15:32:18 -07:00
libzfs_core nvlist: Add nvlist_snprintf() and zfs_dbgmsg_nvlist() 2025-04-18 09:22:16 -04:00
libzfsbootenv nvlist: Add nvlist_snprintf() and zfs_dbgmsg_nvlist() 2025-04-18 09:22:16 -04:00
libzpool Wire O_DIRECT also to Uncached I/O (#17218) 2025-05-13 14:26:55 -07:00
libzstd libzstd: also build with LIBZPOOL_CPPFLAGS 2024-09-09 14:13:27 -07:00
libzutil SPDX: license tags: BSD-3-Clause 2025-03-13 17:56:50 -07:00
Makefile.am libzdb: Initial breakout of libzdb 2024-02-05 10:00:41 -08:00