From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753415AbcKTWeh (ORCPT ); Sun, 20 Nov 2016 17:34:37 -0500 Received: from mail-pf0-f181.google.com ([209.85.192.181]:36458 "EHLO mail-pf0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752029AbcKTWeg (ORCPT ); Sun, 20 Nov 2016 17:34:36 -0500 Message-ID: <1479680873.8455.386.camel@edumazet-glaptop3.roam.corp.google.com> Subject: Re: Linux 4.9-rc6 From: Eric Dumazet To: Linus Torvalds Cc: Linux Kernel Mailing List Date: Sun, 20 Nov 2016 14:27:53 -0800 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 2016-11-20 at 14:05 -0800, Linus Torvalds wrote: > That said, nothing particular is bothering me all that much, but we've > had some of the VMALLOC_STACK fixups continue to trickle in, so I > worry that we're not quite done there yet. And let's see what > Thorsten's regression list looks like next week. So no decision yet, > it could still go either way. Hosts with ~100,000 threads have an issue with /prov/vmallocinfo It can take about 800 usec to skip over ~100,000 struct vmap_area in s_start(), while holding vmap_area_lock spinlock, and therefore blocking fork()/pthread_create(). I presume we can not switch to the rbtree (vmap_area_root) for /proc/vmallocinfo, because this file is seek-able, right ?