mirror_zfs/cmd
Rob Norris 27e9cb5f80 ddt: cleanup the stats & histogram code
Both the API and the code were kinda mangled and I was really struggling
to follow it. The worst offender was the old ddt_stat_add(); after
fixing it up the rest of the changes are mostly knock-on effects and
targets of opportunity.

Note that the old ddt_stat_add() was safe against overflows - it could
produce crazy numbers, but the compiler wouldn't do anything stupid. The
assertions in ddt_stat_sub() go a lot of the way to protecting against
this; getting in a position where overflows are a problem is definitely
a programming error.

Also expanding ddt_stat_add() and ddt_histogram_empty() produces less
efficient assembly. I'm not bothered about this right now though; these
should not be hot functions, and if they are we'll optimise them later.
If we have to go back to the old form, we'll comment it like crazy.

Finally, I've removed the assertion that the bucket will never be
negative, as it will soon be possible to have entries with zero
refcounts: an entry for a block that is no longer on the pool, but is on
the log waiting to be synced out. It might be better to have a separate
bucket for these, since they're still using real space on disk, but
ultimately these stats are driving UI, and for now I've chosen to keep
them matching how they've looked in the past, as well as match the
operators mental model - pool usage is managed elsewhere.

Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
Sponsored-by: Klara, Inc.
Sponsored-by: iXsystems, Inc.
Closes #15895
2024-08-16 12:02:56 -07:00
..
raidz_test RAID-Z expansion feature 2023-11-08 10:19:41 -08:00
zdb ddt: cleanup the stats & histogram code 2024-08-16 12:02:56 -07:00
zed zed: Add deadman-slot_off.sh zedlet 2024-05-29 10:46:41 -07:00
zfs JSON output support for zpool get 2024-08-06 12:47:00 -07:00
zinject Parallel pool import 2024-04-22 09:42:38 -07:00
zpool JSON: Fix class values for mirrored special vdevs 2024-08-06 12:47:58 -07:00
zpool_influxdb Do not report bytes skipped by scan as issued. 2023-06-30 08:47:13 -07:00
zstream zstream: remove duplicate highbit64 definition 2024-08-09 14:31:41 -07:00
arc_summary Once more refactor arc_summary output 2024-08-05 09:22:51 -07:00
arcstat.in Fix arcstats for FreeBSD after zfetch support 2024-04-29 13:28:50 -07:00
dbufstat.in Consider dnode_t allocations in dbuf cache size accounting 2023-11-17 13:25:53 -08:00
fsck.zfs.in cmd: move single-file binaries up, extract udev programs to udev/ 2022-05-10 10:20:34 -07:00
Makefile.am config: use -Wno-format-truncation globally 2024-02-26 12:23:55 -08:00
mount_zfs.c nvpair: Constify string functions 2023-03-14 15:25:50 -07:00
zfs_ids_to_path.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
zgenhostid.c Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
zhack.c Provide macros for setting and getting blkptr birth times 2024-03-25 15:01:54 -07:00
zilstat.in zil: add stats for commit failure/fallback (#16315) 2024-07-25 16:53:59 -07:00
ztest.c ddt: add support for prefetching tables into the ARC 2024-07-26 09:16:18 -07:00
zvol_wait zvol_wait logic may terminate prematurely 2022-10-11 12:12:04 -07:00