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Bug #37570

Fix ZFS ZIOs leak in ddt_sync()

Added by Alexander Motin over 2 years ago. Updated over 2 years ago.

Status:
Done
Priority:
No priority
Assignee:
Alexander Motin
Category:
OS
Target version:
11.2-BETA2
Seen in:
11.2-BETA1
Severity:
Med High
Reason for Closing:
Reason for Blocked:
Needs QA:
No
Needs Doc:
No
Needs Merging:
No
Needs Automation:
No
Support Suite Ticket:
n/a
Hardware Configuration:
ChangeLog Required:
No

Description

At each reboot of FreeNAS I see such message at the end:

Freed UMA keg (zio_cache) was not empty (105 items).  Lost 76 pages of memory.

That is not good.

debug.tgz (144 KB) debug.tgz Alexander Motin, 07/11/2018 07:24 AM
Screen Shot 2018-07-17 at 12.01.46 PM.png (36.6 KB) Screen Shot 2018-07-17 at 12.01.46 PM.png Bonnie Follweiler, 07/17/2018 09:02 AM
21670

Associated revisions

Revision 2eafd853 (diff)
Added by Alexander Motin over 2 years ago

Fix mismerge of sequential scrub code into this branch. This caused one ZIO leak on every transaction group commit. No other branches are affected as far as I can see. Ticket: #37570

History

#1 Updated by Alexander Motin over 2 years ago

It looks like a stable leak during idle:

root@freenas:~ # date ; vmstat -z | grep zio_cache
Wed Jul 11 07:27:21 PDT 2018
zio_cache:             1040,      0,     459,     312,  584037,   0,   0
root@freenas:~ # date ; vmstat -z | grep zio_cache
Wed Jul 11 07:27:23 PDT 2018
zio_cache:             1040,      0,     460,     311,  584082,   0,   0
root@freenas:~ # date ; vmstat -z | grep zio_cache
Wed Jul 11 07:27:27 PDT 2018
zio_cache:             1040,      0,     461,     310,  584099,   0,   0
root@freenas:~ # date ; vmstat -z | grep zio_cache
Wed Jul 11 07:27:32 PDT 2018
zio_cache:             1040,      0,     462,     309,  584117,   0,   0

#2 Updated by Alexander Motin over 2 years ago

  • Status changed from Unscreened to Screened

#3 Updated by Alexander Motin over 2 years ago

  • Subject changed from ZFS may leak ZIOs to ZFS ZIOs leak in ddt_sync()
  • Status changed from Screened to Ready for Testing
  • Target version changed from 11.2-RC2 to 11.2-BETA2
  • Seen in changed from Master - FreeNAS Nightlies to 11.2-BETA1

I've found and fixed (2eafd85312a2) mismerge of sequential scrub code into freenas/11-stable branch. As far as I can see 11.2-BETA1 should be the only affected release. This would cost us a kilobyte of memory every few seconds.

#4 Updated by Dru Lavigne over 2 years ago

  • Subject changed from ZFS ZIOs leak in ddt_sync() to Fix ZFS ZIOs leak in ddt_sync()
  • Needs Doc changed from Yes to No
  • Needs Merging changed from Yes to No

#7 Updated by Bonnie Follweiler over 2 years ago

  • Status changed from Ready for Testing to Passed Testing
  • Needs QA changed from Yes to No

Passed Test on FreeNAS-11.2-MASTER-201807160837

#8 Updated by Dru Lavigne over 2 years ago

  • Status changed from Passed Testing to Done

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