Messages in this thread | | | From | "Elliott, Robert (Server Storage)" <> | Subject | RE: /proc/stat vs. failed order-4 allocation | Date | Thu, 22 May 2014 03:05:35 +0000 |
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> -----Original Message----- > From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel- > owner@vger.kernel.org] On Behalf Of Christoph Hellwig > Sent: Wednesday, May 21, 2014 9:32 AM > To: Heiko Carstens > Cc: Andrew Morton; KAMEZAWA Hiroyuki; Andrea Righi; Eric Dumazet; linux- > kernel@vger.kernel.org; linux-fsdevel@vger.kernel.org; Hendrik Brueckner; > Thorsten Diehl > Subject: Re: /proc/stat vs. failed order-4 allocation > > On Wed, May 21, 2014 at 02:25:21PM +0200, Heiko Carstens wrote: > > Hi all, > > > > I'm just wondering why /proc/stat is a single_open() seq_file and not a > > regular seq_file with an iterator (say 48 online cpus for each iteration > > or something similar). > > Probably because no one sent a patch for it. I'm pretty sure it used the > even more horrible old proc ops before and was converted in batch with > various other files.
https://lkml.org/lkml/2012/1/20/153 worried about performance and led to the current code; the reply in https://lkml.org/lkml/2012/1/23/41 discussed using seq_file, but that idea was rejected at the time.
Be careful about losing consistency of the information for the CPUs.
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