Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936129AbcCQNmE (ORCPT ); Thu, 17 Mar 2016 09:42:04 -0400 Received: from mail.fireflyinternet.com ([87.106.93.118]:65180 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756430AbcCQNmB (ORCPT ); Thu, 17 Mar 2016 09:42:01 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Date: Thu, 17 Mar 2016 13:41:56 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Cc: Andrew Morton , David Rientjes , Roman Peniaev , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm/vmap: Add a notifier for when we run out of vmap address space Message-ID: <20160317134156.GX14143@nuc-i3427.alporthouse.com> Mail-Followup-To: Chris Wilson , intel-gfx@lists.freedesktop.org, Andrew Morton , David Rientjes , Roman Peniaev , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1458215982-13405-1-git-send-email-chris@chris-wilson.co.uk> <1458221699-13734-1-git-send-email-chris@chris-wilson.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1458221699-13734-1-git-send-email-chris@chris-wilson.co.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1533 Lines: 40 On Thu, Mar 17, 2016 at 01:34:59PM +0000, Chris Wilson wrote: > vmaps are temporary kernel mappings that may be of long duration. > Reusing a vmap on an object is preferrable for a driver as the cost of > setting up the vmap can otherwise dominate the operation on the object. > However, the vmap address space is rather limited on 32bit systems and > so we add a notification for vmap pressure in order for the driver to > release any cached vmappings. > > The interface is styled after the oom-notifier where the callees are > passed a pointer to an unsigned long counter for them to indicate if they > have freed any space. > > v2: Guard the blocking notifier call with gfpflags_allow_blocking() > > Signed-off-by: Chris Wilson > Cc: Andrew Morton > Cc: David Rientjes > Cc: Roman Peniaev > Cc: Mel Gorman > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > --- > include/linux/vmalloc.h | 4 ++++ > mm/vmalloc.c | 27 +++++++++++++++++++++++++++ > 2 files changed, 31 insertions(+) > > diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h > index d1f1d338af20..edd676b8e112 100644 > --- a/include/linux/vmalloc.h > +++ b/include/linux/vmalloc.h > @@ -187,4 +187,8 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) > #define VMALLOC_TOTAL 0UL > #endif > > +struct notitifer_block; Omg. /o\ -Chris -- Chris Wilson, Intel Open Source Technology Centre