From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f48.google.com (mail-wm0-f48.google.com [74.125.82.48]) by kanga.kvack.org (Postfix) with ESMTP id E317B6B0038 for ; Thu, 26 Nov 2015 06:25:22 -0500 (EST) Received: by wmuu63 with SMTP id u63so17497326wmu.0 for ; Thu, 26 Nov 2015 03:25:22 -0800 (PST) Received: from fireflyinternet.com (mail.fireflyinternet.com. [87.106.93.118]) by mx.google.com with ESMTP id x7si40690313wjq.156.2015.11.26.03.25.21 for ; Thu, 26 Nov 2015 03:25:21 -0800 (PST) Date: Thu, 26 Nov 2015 11:25:14 +0000 From: Chris Wilson Subject: Re: [PATCH v2] drm/i915: Disable shrinker for non-swapped backed objects Message-ID: <20151126112514.GG23362@nuc-i3427.alporthouse.com> References: <20151124231738.GA15770@nuc-i3427.alporthouse.com> <1448476616-5257-1-git-send-email-chris@chris-wilson.co.uk> <20151125190610.GA12238@cmpxchg.org> <20151125203102.GJ22980@nuc-i3427.alporthouse.com> <20151125204635.GA14536@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151125204635.GA14536@cmpxchg.org> Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, Akash Goel , sourab.gupta@intel.com On Wed, Nov 25, 2015 at 03:46:35PM -0500, Johannes Weiner wrote: > On Wed, Nov 25, 2015 at 08:31:02PM +0000, Chris Wilson wrote: > > On Wed, Nov 25, 2015 at 02:06:10PM -0500, Johannes Weiner wrote: > > > On Wed, Nov 25, 2015 at 06:36:56PM +0000, Chris Wilson wrote: > > > > +static bool swap_available(void) > > > > +{ > > > > + return total_swap_pages || frontswap_enabled; > > > > +} > > > > > > If you use get_nr_swap_pages() instead of total_swap_pages, this will > > > also stop scanning objects once the swap space is full. We do that in > > > the VM to stop scanning anonymous pages. > > > > Thanks. Would EXPORT_SYMBOL_GPL(nr_swap_pages) (or equivalent) be > > acceptable? > > No opposition from me. Just please add a small comment that this is > for shrinkers with swappable objects. diff --git a/mm/swapfile.c b/mm/swapfile.c index 58877312cf6b..1c7861f4c43c 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -48,6 +48,14 @@ static sector_t map_swap_entry(swp_entry_t, struct block_device**); DEFINE_SPINLOCK(swap_lock); static unsigned int nr_swapfiles; atomic_long_t nr_swap_pages; +/* + * Some modules use swappable objects and may try to swap them out under + * memory pressure (via the shrinker). Before doing so, they may wish to + * check to see if any swap space is available. The shrinker also directly + * uses the available swap space to determine whether it can swapout + * anon pages in the same manner. + */ +EXPORT_SYMBOL_GPL(nr_swap_pages); Something like that, after a couple more edits? -Chris -- Chris Wilson, Intel Open Source Technology Centre -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org