From mboxrd@z Thu Jan 1 00:00:00 1970 From: erik quanstrom Date: Wed, 23 Sep 2009 17:25:51 -0400 To: 9fans@9fans.net Message-ID: <2f8c2dddc0483d0478049b74b88c481c@coraid.com> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Subject: Re: [9fans] 9vx (is this the right list)? import issue Topicbox-Message-UUID: 76c7febc-ead5-11e9-9d60-3106f5b1d025 On Wed Sep 23 14:54:47 EDT 2009, rsc@swtch.com wrote: > > how sure are we that 1 holds?  couldn't there be other, > > legitimate and transient errors?  could a user-delivered > > note sneak in and confuse the issue? > > no. at least not if the kernel is working properly. > that's why i said devmnt should enforce the assumption. > it's at most a couple lines of extra code, > whereas the diff you posted was quite a bit longer. it seems to be a big assumption that the whole ip stack and the ethernet driver know the difference between being interrupted before sending or queuing the packet or after. the comment in qbwrite seems to say that you can get interrupted after the pkt has been queued. my approach has the advantage of sidestepping this problem. i don't think 13 changed lines is unreasonable. (without verbose debugging.) - erik