Re: kern/54837: ixl* + wm* interrupt allocation fails

[Shoichi Yamaguchi <s.ymgch228%gmail.com@localhost>]

The following reply was made to PR kern/54837; it has been noted by GNATS.

From: Shoichi Yamaguchi <s.ymgch228%gmail.com@localhost>
To: gnats-bugs%netbsd.org@localhost, kern-bug-people%netbsd.org@localhost,
 gnats-admin%netbsd.org@localhost, netbsd-bugs%netbsd.org@localhost, kardel%netbsd.org@localhost
Cc: 
Subject: Re: kern/54837: ixl* + wm* interrupt allocation fails
Date: Fri, 10 Jan 2020 14:48:11 +0900

 >>  To mitigate this problem, x86's softint bitmask should be
 > 
 > s/softint bitmask/imask, ipending and some others/
 > 
 >>  increased from 32bit to 64bit. Even if it's done, the problem
 >>  won't be solved on many core systems. To resolve the problem,
 >>  IDTVEC should be per-CPU.
 >>  
 
 This problem may be avoided by using "IXL_QUEUE_NUM" added at
 http://mail-index.netbsd.org/source-changes/2020/01/09/msg112737.html
 
 The kernel option can restrict resources related to queue pairs
 including an interrupt when the parameter sets to less than
 the number of cpus.
 
 This is a workaround, not a solution since the restriction causes the
 performance reduction.
 
 -- yamaguchi