From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Weiner Subject: Re: [PATCH v2] drm/i915: Disable shrinker for non-swapped backed objects Date: Thu, 26 Nov 2015 10:40:16 -0500 Message-ID: <20151126154016.GA23976@cmpxchg.org> 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> <20151126112514.GG23362@nuc-i3427.alporthouse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from gum.cmpxchg.org (gum.cmpxchg.org [85.214.110.215]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2C30D6E055 for ; Thu, 26 Nov 2015 07:40:24 -0800 (PST) Content-Disposition: inline In-Reply-To: <20151126112514.GG23362@nuc-i3427.alporthouse.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Chris Wilson Cc: linux-mm@kvack.org, intel-gfx@lists.freedesktop.org, sourab.gupta@intel.com, Akash Goel List-Id: intel-gfx@lists.freedesktop.org T24gVGh1LCBOb3YgMjYsIDIwMTUgYXQgMTE6MjU6MTRBTSArMDAwMCwgQ2hyaXMgV2lsc29uIHdy b3RlOgo+IE9uIFdlZCwgTm92IDI1LCAyMDE1IGF0IDAzOjQ2OjM1UE0gLTA1MDAsIEpvaGFubmVz IFdlaW5lciB3cm90ZToKPiA+IE9uIFdlZCwgTm92IDI1LCAyMDE1IGF0IDA4OjMxOjAyUE0gKzAw MDAsIENocmlzIFdpbHNvbiB3cm90ZToKPiA+ID4gT24gV2VkLCBOb3YgMjUsIDIwMTUgYXQgMDI6 MDY6MTBQTSAtMDUwMCwgSm9oYW5uZXMgV2VpbmVyIHdyb3RlOgo+ID4gPiA+IE9uIFdlZCwgTm92 IDI1LCAyMDE1IGF0IDA2OjM2OjU2UE0gKzAwMDAsIENocmlzIFdpbHNvbiB3cm90ZToKPiA+ID4g PiA+ICtzdGF0aWMgYm9vbCBzd2FwX2F2YWlsYWJsZSh2b2lkKQo+ID4gPiA+ID4gK3sKPiA+ID4g PiA+ICsJcmV0dXJuIHRvdGFsX3N3YXBfcGFnZXMgfHwgZnJvbnRzd2FwX2VuYWJsZWQ7Cj4gPiA+ ID4gPiArfQo+ID4gPiA+IAo+ID4gPiA+IElmIHlvdSB1c2UgZ2V0X25yX3N3YXBfcGFnZXMoKSBp bnN0ZWFkIG9mIHRvdGFsX3N3YXBfcGFnZXMsIHRoaXMgd2lsbAo+ID4gPiA+IGFsc28gc3RvcCBz Y2FubmluZyBvYmplY3RzIG9uY2UgdGhlIHN3YXAgc3BhY2UgaXMgZnVsbC4gV2UgZG8gdGhhdCBp bgo+ID4gPiA+IHRoZSBWTSB0byBzdG9wIHNjYW5uaW5nIGFub255bW91cyBwYWdlcy4KPiA+ID4g Cj4gPiA+IFRoYW5rcy4gV291bGQgRVhQT1JUX1NZTUJPTF9HUEwobnJfc3dhcF9wYWdlcykgKG9y IGVxdWl2YWxlbnQpIGJlCj4gPiA+IGFjY2VwdGFibGU/Cj4gPiAKPiA+IE5vIG9wcG9zaXRpb24g ZnJvbSBtZS4gSnVzdCBwbGVhc2UgYWRkIGEgc21hbGwgY29tbWVudCB0aGF0IHRoaXMgaXMKPiA+ IGZvciBzaHJpbmtlcnMgd2l0aCBzd2FwcGFibGUgb2JqZWN0cy4KPiAKPiBkaWZmIC0tZ2l0IGEv bW0vc3dhcGZpbGUuYyBiL21tL3N3YXBmaWxlLmMKPiBpbmRleCA1ODg3NzMxMmNmNmIuLjFjNzg2 MWY0YzQzYyAxMDA2NDQKPiAtLS0gYS9tbS9zd2FwZmlsZS5jCj4gKysrIGIvbW0vc3dhcGZpbGUu Ywo+IEBAIC00OCw2ICs0OCwxNCBAQCBzdGF0aWMgc2VjdG9yX3QgbWFwX3N3YXBfZW50cnkoc3dw X2VudHJ5X3QsIHN0cnVjdCBibG9ja19kZXZpY2UqKik7Cj4gIERFRklORV9TUElOTE9DSyhzd2Fw X2xvY2spOwo+ICBzdGF0aWMgdW5zaWduZWQgaW50IG5yX3N3YXBmaWxlczsKPiAgYXRvbWljX2xv bmdfdCBucl9zd2FwX3BhZ2VzOwo+ICsvKgo+ICsgKiBTb21lIG1vZHVsZXMgdXNlIHN3YXBwYWJs ZSBvYmplY3RzIGFuZCBtYXkgdHJ5IHRvIHN3YXAgdGhlbSBvdXQgdW5kZXIKPiArICogbWVtb3J5 IHByZXNzdXJlICh2aWEgdGhlIHNocmlua2VyKS4gQmVmb3JlIGRvaW5nIHNvLCB0aGV5IG1heSB3 aXNoIHRvCj4gKyAqIGNoZWNrIHRvIHNlZSBpZiBhbnkgc3dhcCBzcGFjZSBpcyBhdmFpbGFibGUu IFRoZSBzaHJpbmtlciBhbHNvIGRpcmVjdGx5Cj4gKyAqIHVzZXMgdGhlIGF2YWlsYWJsZSBzd2Fw IHNwYWNlIHRvIGRldGVybWluZSB3aGV0aGVyIGl0IGNhbiBzd2Fwb3V0Cj4gKyAqIGFub24gcGFn ZXMgaW4gdGhlIHNhbWUgbWFubmVyLgo+ICsgKi8KPiArRVhQT1JUX1NZTUJPTF9HUEwobnJfc3dh cF9wYWdlcyk7Cj4gCj4gU29tZXRoaW5nIGxpa2UgdGhhdCwgYWZ0ZXIgYSBjb3VwbGUgbW9yZSBl ZGl0cz8KClRoZSBsYXN0IHNlbnRlbmNlIGlzbid0IG5lY2Vzc2FyeSBJTU8sIGJ1dCBvdGhlciB0 aGFuIHRoYXQgaXQgbG9va3MKZ29vZCB0byBtZS4KX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX18KSW50ZWwtZ2Z4IG1haWxpbmcgbGlzdApJbnRlbC1nZnhAbGlz dHMuZnJlZWRlc2t0b3Aub3JnCmh0dHA6Ly9saXN0cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9s aXN0aW5mby9pbnRlbC1nZngK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f50.google.com (mail-wm0-f50.google.com [74.125.82.50]) by kanga.kvack.org (Postfix) with ESMTP id 166186B0038 for ; Thu, 26 Nov 2015 10:40:27 -0500 (EST) Received: by wmec201 with SMTP id c201so36486406wme.0 for ; Thu, 26 Nov 2015 07:40:26 -0800 (PST) Received: from gum.cmpxchg.org (gum.cmpxchg.org. [85.214.110.215]) by mx.google.com with ESMTPS id 132si4255546wmd.41.2015.11.26.07.40.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 26 Nov 2015 07:40:25 -0800 (PST) Date: Thu, 26 Nov 2015 10:40:16 -0500 From: Johannes Weiner Subject: Re: [PATCH v2] drm/i915: Disable shrinker for non-swapped backed objects Message-ID: <20151126154016.GA23976@cmpxchg.org> 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> <20151126112514.GG23362@nuc-i3427.alporthouse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151126112514.GG23362@nuc-i3427.alporthouse.com> Sender: owner-linux-mm@kvack.org List-ID: To: Chris Wilson Cc: intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, Akash Goel , sourab.gupta@intel.com On Thu, Nov 26, 2015 at 11:25:14AM +0000, Chris Wilson wrote: > 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? The last sentence isn't necessary IMO, but other than that it looks good to me. -- 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