From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 63804C83F16 for ; Mon, 28 Aug 2023 09:39:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230144AbjH1Ji5 (ORCPT ); Mon, 28 Aug 2023 05:38:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230190AbjH1Jik (ORCPT ); Mon, 28 Aug 2023 05:38:40 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 623A1114 for ; Mon, 28 Aug 2023 02:38:36 -0700 (PDT) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by madras.collabora.co.uk (Postfix) with ESMTPSA id 16EBA660719F; Mon, 28 Aug 2023 10:38:34 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1693215514; bh=xNMyWokm068wowm7PBLRXVEkKpUJiarJWqqqpBLI9vs=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CoJYyz7XHczKOPC18Kap7wWKCoi8DSh+JbLJLzAdY30QkSF7CpzwFCS4peVuI6G4G E7+34r2HSpN8c75/T5E+JerwJj7FDJVxVcsqOQDBLE9OAiPzykAnk2LDC3CBBdI9t1 19y/XuWEFFEzbK+ULKya4X6BWf5wz5eaaciNvw3tzcrZLf+QmD94Iulx+znm7wPm5x jt1O4h9vZvYLEKvD4g3FRu8gr2Kux5K9z3LPPoN4hZBg3+CMZ7Ep3RB1MYbP51Kav5 bDOjgufY3XVQ8LnH23OhbnA1+obEbJUnNLloj3fWzKnM2riEXzO/QN156CuMMasyys uLDu3YpVUgGqQ== Date: Mon, 28 Aug 2023 11:38:31 +0200 From: Boris Brezillon To: Dmitry Osipenko Cc: David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Christian =?UTF-8?B?S8O2bmln?= , Qiang Yu , Steven Price , Emma Anholt , Melissa Wen , Will Deacon , Peter Zijlstra , Boqun Feng , Mark Rutland , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, virtualization@lists.linux-foundation.org, intel-gfx@lists.freedesktop.org Subject: Re: [PATCH v15 12/23] drm/shmem-helper: Add and use pages_pin_count Message-ID: <20230828113831.0e31c5d0@collabora.com> In-Reply-To: <20230827175449.1766701-13-dmitry.osipenko@collabora.com> References: <20230827175449.1766701-1-dmitry.osipenko@collabora.com> <20230827175449.1766701-13-dmitry.osipenko@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 27 Aug 2023 20:54:38 +0300 Dmitry Osipenko wrote: > Add separate pages_pin_count for tracking of whether drm-shmem pages are > moveable or not. With the addition of memory shrinker support to drm-shmem, > the pages_use_count will no longer determine whether pages are hard-pinned > in memory, but whether pages exit and are soft-pinned (and could be swapped ^exist > out). The pages_pin_count > 1 will hard-pin pages in memory. > > Suggested-by: Boris Brezillon > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 22 +++++++++++++++++----- > include/drm/drm_gem_shmem_helper.h | 10 ++++++++++ > 2 files changed, 27 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index d545d3d227d7..1a7e5c332fd8 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -234,14 +234,22 @@ static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem) > > dma_resv_assert_held(shmem->base.resv); > > + if (kref_get_unless_zero(&shmem->pages_pin_count)) > + return 0; > + > ret = drm_gem_shmem_get_pages_locked(shmem); > + if (!ret) > + kref_init(&shmem->pages_pin_count); > > return ret; > } > > -static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem) > +static void drm_gem_shmem_kref_unpin_pages(struct kref *kref) > { > - dma_resv_assert_held(shmem->base.resv); > + struct drm_gem_shmem_object *shmem; > + > + shmem = container_of(kref, struct drm_gem_shmem_object, > + pages_pin_count); > > drm_gem_shmem_put_pages_locked(shmem); > } > @@ -263,6 +271,9 @@ int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem) > > drm_WARN_ON(obj->dev, obj->import_attach); > > + if (kref_get_unless_zero(&shmem->pages_pin_count)) > + return 0; > + > ret = dma_resv_lock_interruptible(shmem->base.resv, NULL); > if (ret) > return ret; > @@ -286,9 +297,10 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem) > > drm_WARN_ON(obj->dev, obj->import_attach); > > - dma_resv_lock(shmem->base.resv, NULL); > - drm_gem_shmem_unpin_locked(shmem); > - dma_resv_unlock(shmem->base.resv); > + if (kref_put_dma_resv(&shmem->pages_pin_count, > + drm_gem_shmem_kref_unpin_pages, > + obj->resv, NULL)) > + dma_resv_unlock(obj->resv); > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_unpin); > > diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h > index ec2d8b24e3cf..afb7cd671e2a 100644 > --- a/include/drm/drm_gem_shmem_helper.h > +++ b/include/drm/drm_gem_shmem_helper.h > @@ -39,6 +39,16 @@ struct drm_gem_shmem_object { > */ > unsigned int pages_use_count; > > + /** > + * @pages_pin_count: > + * > + * Reference count on the pinned pages table. > + * The pages allowed to be evicted and purged by memory > + * shrinker only when the count is zero, otherwise pages > + * are hard-pinned in memory. > + */ > + struct kref pages_pin_count; > + > /** > * @madv: State for madvise > *