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Bug #12267
closed
zfs '::abuf_find' dcmd is broken
Status:
Closed
Priority:
Normal
Assignee:
-
Category:
mdb - modular debugger
Start date:
Due date:
% Done:
100%
Estimated time:
Difficulty:
Medium
Tags:
Gerrit CR:
Description
Attempting to use ::abuf_find 1 2 in mdb fails with:
> ::abuf_find 1 2 mdb: invalid or uninitialized list_t at 0xfffffffffc08b600 mdb: can't walk ARC_mru: failed to initialize walk
The problem is that arc_state_t no longer contains a list_t, but a multilist_t. Most likely changing the mdb command to use the multilist walker will fix this.
It appears this was broken by:
commit 244781f10dcd82684fd8163c016540667842f203
Author: Prakash Surya <prakash.surya@delphix.com>
Date: Mon Jan 12 19:52:19 2015 -0800
5497 lock contention on arcs_mtx
Related issues
Updated by Jason King over 1 year ago
- Related to Bug #5497: lock contention on arcs_mtx added
Updated by Jason King over 1 year ago
- Related to Bug #12269: mdb multilist walker should be a layered walker added
Updated by Jason King over 1 year ago
To test, with the modified zfs mdb module loaded, I first found an arc_buf_hdr_t by walking the ARC MRU list:
> ARC_mru::print arc_state_t arcs_list
arcs_list = [ 0, 0xfffffe16d9ecd7e8, 0xfffffe16d9ecd808 ]
> 0xfffffe16d9ecd7e8::walk multilist ! head -1
0xfffffe174f26eb40
> 0xfffffe174f26eb40::print arc_buf_hdr_t b_dva
b_dva = {
b_dva.dva_word = [ 0x10, 0x2f8f880 ]
}
Using the DVA, I then attempted to find it with ::abuf_find:
> ::abuf_find 10 2f8f880 0xfffffe174f26eb40
Without the change, mdb fails to find the arc_buf_hdr_t:
> ::abuf_find 10 2f8f880 mdb: invalid or uninitialized list_t at 0xfffffffffc02c220 mdb: can't walk ARC_mru: failed to initialize walk
Updated by Electric Monk over 1 year ago
- % Done changed from 0 to 100
- Status changed from New to Closed
git commit 8b06eaf6acc31eaadddc0fec3df9d1a4294b7cc2
commit 8b06eaf6acc31eaadddc0fec3df9d1a4294b7cc2
Author: Jason King <jason.king@joyent.com>
Date: 2020-02-04T00:01:07.000Z
12267 zfs '::abuf_find' dcmd is broken
Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>
Reviewed by: Kody Kantor <kody@kkantor.com>
Reviewed by: Igor Kozhukhov <igor@dilos.org>
Approved by: Dan McDonald <danmcd@joyent.com>
Updated by Jason King over 1 year ago
- Is duplicate of Bug #7169: mdb '::abuf_find 1 2' - failed added
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