Re: kern/57690: XEN pvh guest GENERIC: xennet0: no rx clusters (possible mbuf/pool leak)

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

The following reply was made to PR kern/57690; it has been noted by GNATS.

From: Manuel Bouyer <bouyer%antioche.eu.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: kern-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost,
        kardel%netbsd.org@localhost
Subject: Re: kern/57690: XEN pvh guest GENERIC: xennet0: no rx clusters
 (possible mbuf/pool leak)
Date: Fri, 10 Nov 2023 14:58:22 +0100

 On Fri, Nov 10, 2023 at 01:50:01PM +0000, Frank Kardel wrote:
 > The following reply was made to PR kern/57690; it has been noted by GNATS.
 > 
 > From: Frank Kardel <kardel%netbsd.org@localhost>
 > To: gnats-bugs%netbsd.org@localhost
 > Cc: 
 > Subject: Re: kern/57690: XEN pvh guest GENERIC: xennet0: no rx clusters
 >  (possible mbuf/pool leak)
 > Date: Fri, 10 Nov 2023 14:48:33 +0100
 > 
 >  Well, after running a bit with a freshly started kernel I do see 
 >  releases after some more traffic, so that part does
 >  seem to work.
 >  
 >  Memory resource pool statistics
 >  Name        Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg 
 >  Maxpg Idle
 >  xnfrx       4096   203576    6   203234  9728  9358   370   873 0   inf   28
 >  
 >  
 >  Why there are allocation failures and reduced performance issues still 
 >  needs to be examined.
 
 maybe it's a general RAM shortage ? The allocations happens from interrupt
 context, so if there is no free page it can fail.
 
 Both MGETHDR and pool_cache_get_paddr() from if_xennetrxbuf_cache fails, so
 it seems just that there is no free page at some point.
 
 I do see there diagnostif printfs from time to time but the system
 recovers.
 
 -- 
 Manuel Bouyer <bouyer%antioche.eu.org@localhost>
      NetBSD: 26 ans d'experience feront toujours la difference
 --