From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754162AbbHMVXX (ORCPT ); Thu, 13 Aug 2015 17:23:23 -0400 Received: from mail-vk0-f42.google.com ([209.85.213.42]:34616 "EHLO mail-vk0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751773AbbHMVXW (ORCPT ); Thu, 13 Aug 2015 17:23:22 -0400 X-Greylist: delayed 453 seconds by postgrey-1.27 at vger.kernel.org; Thu, 13 Aug 2015 17:23:22 EDT MIME-Version: 1.0 In-Reply-To: References: <20150812210027.88dfcf90.akpm@linux-foundation.org> Date: Thu, 13 Aug 2015 14:15:49 -0700 Message-ID: Subject: Re: get_vmalloc_info() and /proc/meminfo insanely expensive From: Tony Luck To: Linus Torvalds Cc: Andrew Morton , Joonsoo Kim , Al Viro , Linux Kernel Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 13, 2015 at 11:32 AM, Linus Torvalds wrote: > And I also can't find it in myself to care about the "on 32-bit, > jiffies wraps in 49 days if HZ is 1000". If somebody carefully avoids > ever reading /proc/meminfo for 49 days, and then reads it in _just_ > the right second, and gets a really stale value, I'm just going to do > my honey badger impression. could you at least care enough to write that as if (time_after(now, last + HZ)) { -Tony