PR/60776 CVS commit: src/sys/kern

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

The following reply was made to PR kern/60776; it has been noted by GNATS.

From: "Taylor R Campbell" <riastradh%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/60776 CVS commit: src/sys/kern
Date: Wed, 23 Sep 2026 19:07:40 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Wed Sep 23 19:07:40 UTC 2026
 
 Modified Files:
 	src/sys/kern: kern_turnstile.c
 
 Log Message:
 Revert "turnstile(9): Fix priority inheritance if trylock requires restart."
 
 This was originally done in an attempt to resolve the issue described
 in:
 
 PR kern/60739: Turnstile priority inheritance short-circuits walking
 of waiter chain when trylock fails
 
 But it may have broken other things:
 
 PR kern/60776: reproducable assertion failure with today's current
 
 > Today's amd64 kernel reproducably crashes for me when running build.sh.
 >
 > [ 4043.4787057] panic: kernel diagnostic assertion "lwp_eprio(l) >= ts->ts_eprio" failed: file "../../../../kern/kern_turnstile.c", line 356
 > [ 4043.6286910] cpu1: Begin traceback...
 > [ 4043.6686907] vpanic() at netbsd:vpanic+0x189
 > [ 4043.7186903] kern_assert() at netbsd:kern_assert+0x4b
 > [ 4043.7786898] turnstile_wakeup() at netbsd:turnstile_wakeup+0x2c5
 > [ 4043.8586891] ubc_alloc.constprop.0() at netbsd:ubc_alloc.constprop.0+0x680
 > [ 4043.9386885] ubc_uiomove() at netbsd:ubc_uiomove+0x108
 > [ 4043.9986879] ffs_write() at netbsd:ffs_write+0x297
 > [ 4044.0586874] VOP_WRITE() at netbsd:VOP_WRITE+0x78
 > [ 4044.1086870] vn_write() at netbsd:vn_write+0xce
 > [ 4044.1686865] dofilewrite() at netbsd:dofilewrite+0x80
 > [ 4044.2286860] sys_write() at netbsd:sys_write+0x49
 > [ 4044.2786855] syscall() at netbsd:syscall+0x9d
 
 So let's back it out for now pending further analysis.
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.57 -r1.58 src/sys/kern/kern_turnstile.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.