Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752829Ab3ISG5H (ORCPT ); Thu, 19 Sep 2013 02:57:07 -0400 Received: from mail-ie0-f169.google.com ([209.85.223.169]:45103 "EHLO mail-ie0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752676Ab3ISG5F (ORCPT ); Thu, 19 Sep 2013 02:57:05 -0400 MIME-Version: 1.0 X-Originating-IP: [178.83.130.250] In-Reply-To: <20130918203822.GA4330@dastard> References: <1379495401-18279-1-git-send-email-daniel.vetter@ffwll.ch> <5239829F.4080601@t-online.de> <20130918203822.GA4330@dastard> Date: Thu, 19 Sep 2013 08:57:04 +0200 Message-ID: Subject: Re: [Intel-gfx] [PATCH] [RFC] mm/shrinker: Add a shrinker flag to always shrink a bit From: Daniel Vetter To: Dave Chinner Cc: Knut Petersen , Linux MM , Rik van Riel , Intel Graphics Development , Johannes Weiner , LKML , DRI Development , Michal Hocko , Mel Gorman , Glauber Costa , Andrew Morton , Linus Torvalds Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1288 Lines: 29 On Wed, Sep 18, 2013 at 10:38 PM, Dave Chinner wrote: > No, that's wrong. ->count_objects should never ass SHRINK_STOP. > Indeed, it should always return a count of objects in the cache, > regardless of the context. > > SHRINK_STOP is for ->scan_objects to tell the shrinker it can make > any progress due to the context it is called in. This allows the > shirnker to defer the work to another call in a different context. > However, if ->count-objects doesn't return a count, the work that > was supposed to be done cannot be deferred, and that is what > ->count_objects should always return the number of objects in the > cache. So we should rework the locking in the drm/i915 shrinker to be able to always count objects? Thus far no one screamed yet that we're not really able to do that in all call contexts ... So should I revert 81e49f or will the early return 0; completely upset the core shrinker logic? -Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/