re: kern/19803 (usbd_alloc_buffer fails often)

[matthew green <mrg%eterna.com.au@localhost>]

The following reply was made to PR kern/19803; it has been noted by GNATS.

From: matthew green <mrg%eterna.com.au@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
    gnats-admin%netbsd.org@localhost, maya%NetBSD.org@localhost, toshii%netbsd.org@localhost
Subject: re: kern/19803 (usbd_alloc_buffer fails often)
Date: Tue, 06 Aug 2019 11:10:00 +1000

 > State-Changed-From-To: open->closed
 > State-Changed-By: maya%NetBSD.org@localhost
 > State-Changed-When: Mon, 05 Aug 2019 22:13:36 +0000
 > State-Changed-Why:
 > This PR documents an issue but:
 > - Is stale, so likely to be ignored,
 > - Doesn't contain the right information.
 > =
 
 > This is likely a memory fragmentation issue. I am under the impression U=
 SB still uses
 > more contiguous memory than it absolutely has to, so perhaps we could us=
 e a reminder,
 > but this PR isn't a good reminder because it doesn't talk about it.
 > =
 
 > Memory fragmentation issues have come and gone in netbsd since the filin=
 g of this PR,
 > so perhaps things are better or worse now. It's unclear.
 
 AFAICT, this problem is still 100% the same.
 
 now that your update talks about fragmentation, i think the
 PR has all the details it needs -- it certainly happens on
 a 64GB machine with a lot of free ram that was active in
 recent times.  enough concurrent 4095mb dd's ends up making
 it work again.
 
 unless the problem is documented in another PR, i think this
 one should be re-opened.
 
 
 .mrg.