mirror_zfs/lib
Alexander Motin 54278533a4 Reduce and handle EAGAIN errors on AIO label reads
At least FreeBSD has a limit of 256 simultaneous AIO requests per
process. Attempt to issue more results in EAGAIN errors. Since we
issue 4 requests per disk/partition from 2xCPUs threads, it is
quite easy to reach that limit on large systems, that results in
random pool import failures.  It annoyed me for quite a while on
a system with 64 CPUs and 70+ partitioned disks.

This patch from one side limits the number of threads to avoid the
error, while from another should softly fall back to sync reads in
case of error.  It takes into account _SC_AIO_MAX as a system-wide
AIO limit and _SC_AIO_LISTIO_MAX as a closest value to per-process
limit.  The last not exactly right, but it is the best I found.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Alexander Motin <mav@FreeBSD.org>
Sponsored by: iXsystems, Inc.
Closes #16551
2024-11-05 15:43:52 -08:00
..
libavl cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libefi Replace P2ALIGN with P2ALIGN_TYPED and delete P2ALIGN. 2024-05-13 10:27:38 -05:00
libicp Add generic implementation handling and SHA2 impl 2023-03-02 13:52:21 -08:00
libnvpair nvpair: Constify string functions 2023-03-14 15:25:50 -07:00
libshare Fix handling of DNS names with '-' in them for sharenfs 2024-11-05 15:43:52 -08:00
libspl libspl_assert: always link -lpthread on FreeBSD 2024-07-17 14:54:46 -07:00
libtpool Add <limits.h> header 2022-11-28 13:24:17 -08:00
libunicode cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libuutil GCC: Fixes for gcc 14 on Fedora 40 2024-04-29 13:50:05 -07:00
libzfs Use memset to zero stack allocations containing unions 2024-07-17 14:54:47 -07:00
libzfs_core Fix occasional rsend test crashes 2023-09-22 16:13:20 -07:00
libzfsbootenv nvpair: Constify string functions 2023-03-14 15:25:50 -07:00
libzpool Add mutex_enter_interruptible() for interruptible sleeping IOCTLs 2023-11-06 16:47:41 -08:00
libzstd cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libzutil Reduce and handle EAGAIN errors on AIO label reads 2024-11-05 15:43:52 -08:00
Makefile.am autoconf: use include directives instead of recursing down lib 2022-05-10 10:18:11 -07:00