Files
mirror_zfs/cmd/zed
наб 3e04897edc zed: implement close_from() in terms of /proc/self/fd, if available
/dev/fd on Darwin

Consider the following strace output:
  prlimit64(0, RLIMIT_NOFILE, NULL, {rlim_cur=1024, rlim_max=1024*1024}) = 0

Yes, that is well over a million file descriptors!

This reduces the ZED start-up time from "at least a second" to
"instantaneous", and, under strace, from "don't even try" to "usable"
by simple virtue of doing five syscalls instead of over a million;
in most cases the main loop does nothing

Recent Linuxes (5.8+) have close_range(2) for this, but that's an
overoptimisation (and libcs don't have wrappers for it yet)

This is also run by the ZEDLET pre-exec. Compare:
  Finished "all-syslog.sh" eid=13 pid=6717 time=1.027100s exit=0
  Finished "history_event-zfs-list-cacher.sh" eid=13 pid=6718 time=1.046923s exit=0
to
  Finished "all-syslog.sh" eid=12 pid=4834 time=0.001836s exit=0
  Finished "history_event-zfs-list-cacher.sh" eid=12 pid=4835 time=0.001346s exit=0
lol

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #11834
2021-11-12 15:24:36 -08:00
..
2021-06-23 13:22:15 -07:00