From: Andrew Morton <akpm@linux-foundation.org>
To: Eric Wong <normalperson@yhbt.net>
Cc: Davide Libenzi <davidel@xmailserver.org>,
Al Viro <viro@ZenIV.linux.org.uk>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] epoll: trim epitem by one cache line on x86_64
Date: Fri, 8 Mar 2013 15:54:10 -0800 [thread overview]
Message-ID: <20130308155410.3c63f24ee28e6532006cb0d4@linux-foundation.org> (raw)
In-Reply-To: <20130307103240.GA24132@dcvr.yhbt.net>
On Thu, 7 Mar 2013 10:32:40 +0000 Eric Wong <normalperson@yhbt.net> wrote:
> Andrew Morton <akpm@linux-foundation.org> wrote:
> > It's going to be hard to maintain this - someone will change something
> > sometime and break it. I suppose we could add a runtime check if we
> > cared enough. Adding a big fat comment to struct epitem might help.
>
> Thanks for looking at this patch. I'll send a patch with a comment
> about keeping epitem size in check. Also, would adding (with comments):
>
> BUILD_BUG_ON(sizeof(struct epitem) > 128);
>
> ...be too heavy-handed? I used that in my testing. I'll check for:
> sizeof(void *) <= 8 too; in case 128-bit machines appear...
I guess such a check might avoid accidents in the future. If it
becomes a problem, we can always delete it.
next prev parent reply other threads:[~2013-03-08 23:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-04 11:29 [PATCH] epoll: trim epitem by one cache line on x86_64 Eric Wong
2013-03-06 22:37 ` Andrew Morton
2013-03-07 10:32 ` Eric Wong
2013-03-08 23:54 ` Andrew Morton [this message]
2013-03-09 0:41 ` [PATCH] epoll: comment + BUILD_BUG_ON to prevent epitem bloat Eric Wong
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