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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2E12FC001DF for ; Tue, 25 Jul 2023 07:14:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 69C8810E39F; Tue, 25 Jul 2023 07:14:55 +0000 (UTC) Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by gabe.freedesktop.org (Postfix) with ESMTPS id E194410E39D for ; Tue, 25 Jul 2023 07:14:52 +0000 (UTC) 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 0534C6606FD7; Tue, 25 Jul 2023 08:14:50 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1690269291; bh=2Up7Q4ggLqZwRNdv/plAaqb8BMBgbL4oTYcjSdMQnow=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=GLcosbsF9805iCbE8eMvWlBaeBQxI53nor3WoWEKfZ5Hj/OXrrl3yEPPnLRW+TpRz iKuHpSPyTIWyXIT29oO+7L7G+HITZzPd4GlWnb38HINfGIiom/lq3+h9ArzmviwEKp WbXCLx+qEhV5lJie++W+SiYk79wKqF3enWPkKVXfXpkajuostTzGKwBGQ2bOnV3sKw BWOYiHqmLRPWxmky2VY5WkUB3em82QbGqEQD5rASxpWTChzgkqoQL72TsEvfif2TWq 5lPoW74N+x6kXkS6Qp1yk9zEYkaG60R5mPY5EfQv8zb7R5eCfTbNAoVM1tb9i+za3d tdd/dDLnHluxA== Date: Tue, 25 Jul 2023 09:14:48 +0200 From: Boris Brezillon To: Dmitry Osipenko Subject: Re: [PATCH v14 01/12] drm/shmem-helper: Factor out pages alloc/release from drm_gem_shmem_get/put_pages() Message-ID: <20230725091448.7ac0c4aa@collabora.com> In-Reply-To: <20230722234746.205949-2-dmitry.osipenko@collabora.com> References: <20230722234746.205949-1-dmitry.osipenko@collabora.com> <20230722234746.205949-2-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 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kernel@collabora.com, Thomas Zimmermann , Emma Anholt , Christian =?UTF-8?B?S8O2bmln?= , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Maxime Ripard , Gurchetan Singh , Melissa Wen , Gerd Hoffmann , Steven Price , virtualization@lists.linux-foundation.org, Qiang Yu Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Sun, 23 Jul 2023 02:47:35 +0300 Dmitry Osipenko wrote: > Factor out pages allocation from drm_gem_shmem_get_pages() into > drm_gem_shmem_acquire_pages() function and similar for the put_pages() > in a preparation for addition of shrinker support to drm-shmem. > > Once shrinker will be added, the pages_use_count>0 will no longer determine > whether pages are pinned because pages could be swapped out by the shrinker > and then pages_use_count will be greater than 0 in this case. We will add > new pages_pin_count in a later patch. > > The new common drm_gem_shmem_acquire/release_pages() will be used by > shrinker code for performing the page swapping. > > Signed-off-by: Dmitry Osipenko > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 65 ++++++++++++++++++++------ > 1 file changed, 52 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c > index a783d2245599..267153853e2c 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -165,21 +165,26 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) > } > EXPORT_SYMBOL_GPL(drm_gem_shmem_free); > > -static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > +static int > +drm_gem_shmem_acquire_pages(struct drm_gem_shmem_object *shmem) > { > struct drm_gem_object *obj = &shmem->base; > struct page **pages; > > dma_resv_assert_held(shmem->base.resv); Not directly related to this patch, but can we start using _locked suffixes for any function that's expecting the dma-resv lock to be held? > > - if (shmem->pages_use_count++ > 0) > - return 0; > + if (shmem->madv < 0) { > + drm_WARN_ON(obj->dev, shmem->pages); > + return -ENOMEM; > + } > + > + if (drm_WARN_ON(obj->dev, !shmem->pages_use_count)) > + return -EINVAL; > > pages = drm_gem_get_pages(obj); > if (IS_ERR(pages)) { > drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n", > PTR_ERR(pages)); > - shmem->pages_use_count = 0; > return PTR_ERR(pages); > } > > @@ -198,6 +203,48 @@ static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > return 0; > } > > +static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem) > +{ > + int err; > + > + dma_resv_assert_held(shmem->base.resv); > + > + if (shmem->madv < 0) > + return -ENOMEM; > + > + if (shmem->pages_use_count++ > 0) > + return 0; > + > + err = drm_gem_shmem_acquire_pages(shmem); > + if (err) > + goto err_zero_use; > + > + return 0; > + > +err_zero_use: > + shmem->pages_use_count = 0; > + > + return err; > +} > + > +static void > +drm_gem_shmem_release_pages(struct drm_gem_shmem_object *shmem) > +{ > + struct drm_gem_object *obj = &shmem->base; > + > + dma_resv_assert_held(shmem->base.resv); > + > +#ifdef CONFIG_X86 > + if (shmem->map_wc) > + set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); > +#endif > + > + drm_gem_put_pages(obj, shmem->pages, > + shmem->pages_mark_dirty_on_put, > + shmem->pages_mark_accessed_on_put); > + shmem->pages = NULL; > +} > + > /* > * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object > * @shmem: shmem GEM object > @@ -216,15 +263,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem) > if (--shmem->pages_use_count > 0) > return; > > -#ifdef CONFIG_X86 > - if (shmem->map_wc) > - set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT); > -#endif > - > - drm_gem_put_pages(obj, shmem->pages, > - shmem->pages_mark_dirty_on_put, > - shmem->pages_mark_accessed_on_put); > - shmem->pages = NULL; > + drm_gem_shmem_release_pages(shmem); > } > EXPORT_SYMBOL(drm_gem_shmem_put_pages); >