Re: kern/59411 (deadlock on mbuf pool)

["Tobias Nygren via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR kern/59411; it has been noted by GNATS.

From: Tobias Nygren <tnn%NetBSD.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: 
Subject: Re: kern/59411 (deadlock on mbuf pool)
Date: Sat, 17 May 2025 13:28:17 +0200

 On Fri, 16 May 2025 02:29:22 +0000 (UTC)
 riastradh%NetBSD.org@localhost wrote:
 
 > Until subr_pool.c rev. 1.220 in 2017, pool_grow dropped the lock around
 > pool_allocator_alloc and thus avoided this deadlock, but it's unclear
 > why that change was made.
 
 I was unable to rehydrate all brain cells that were involved in this,
 but this is the preceeding discussion on current-users which has some context:
 https://mail-index.netbsd.org/current-users/2017/12/29/msg033000.html
 
 In summary the change intends to work around a hang that was introduced with this commit:
 https://mail-index.netbsd.org/source-changes/2017/12/16/msg090490.html