From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f46.google.com (mail-pb0-f46.google.com [209.85.160.46]) by kanga.kvack.org (Postfix) with ESMTP id 4E67F6B0039 for ; Thu, 21 Nov 2013 06:19:28 -0500 (EST) Received: by mail-pb0-f46.google.com with SMTP id md12so4922632pbc.5 for ; Thu, 21 Nov 2013 03:19:27 -0800 (PST) Received: from mga02.intel.com (mga02.intel.com. [134.134.136.20]) by mx.google.com with ESMTP id qu5si4089140pbc.30.2013.11.21.03.19.26 for ; Thu, 21 Nov 2013 03:19:27 -0800 (PST) From: "Kirill A. Shutemov" In-Reply-To: <20131120144014.386293ce24e7b298ebab7b8e@linux-foundation.org> References: <20131120174211.GF10323@ZenIV.linux.org.uk> <20131120174712.GG10323@ZenIV.linux.org.uk> <20131120144014.386293ce24e7b298ebab7b8e@linux-foundation.org> Subject: Re: [git pull] vfs.git bits and pieces Content-Transfer-Encoding: 7bit Message-Id: <20131121111906.B97AEE0090@blue.fi.intel.com> Date: Thu, 21 Nov 2013 13:19:06 +0200 (EET) Sender: owner-linux-mm@kvack.org List-ID: To: Linus Torvalds , Andrew Morton Cc: Al Viro , "Kirill A. Shutemov" , Linux Kernel Mailing List , linux-fsdevel , Ingo Molnar , Peter Zijlstra , linux-mm@kvack.org Andrew Morton wrote: > On Wed, 20 Nov 2013 14:33:35 -0800 Linus Torvalds wrote: > > > On Wed, Nov 20, 2013 at 9:47 AM, Al Viro wrote: > > > > > > BTW, something odd happened to mm/memory.c - either a mangled patch > > > or a lost followup: > > > > > > commit ea1e7ed33708 > > > mm: create a separate slab for page->ptl allocation > > > > > > Fair enough, and yes, it does create that separate slab. The problem is, > > > it's still using kmalloc/kfree for those beasts - page_ptl_cachep isn't > > > used at all... > > > > Ok, it looks straightforward enough to just replace the kmalloc/kfree > > with using a slab allocation using the page_ptl_cachep pointer. I'd do > > it myself, but I would like to know how it got lost? Also, much > > testing to make sure the cachep is initialized early enough. > > agh, I went through hell keeping that patch alive and it appears I lost > some of it. Actually, I've lost it while adding BLOATED_SPINLOCKS :( > > Or should we just revert the commit that added the pointless/unused > > slab pointer? > > > > Andrew, Kirill, comments? > > Let's just kill it please. We can try again for 3.14. I'm okay with that. Only side note: it's useful not only for debug case, but also for PREEMPT_RT where spinlock_t is always bloated. Fixed patch: