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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ABB4C433F5 for ; Thu, 20 Jan 2022 14:59:16 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 82E216B009D; Thu, 20 Jan 2022 09:59:15 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 7DC966B00A0; Thu, 20 Jan 2022 09:59:15 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6A47A6B00A2; Thu, 20 Jan 2022 09:59:15 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0123.hostedemail.com [216.40.44.123]) by kanga.kvack.org (Postfix) with ESMTP id 58EA96B009D for ; Thu, 20 Jan 2022 09:59:15 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id BA92596359 for ; Thu, 20 Jan 2022 14:59:14 +0000 (UTC) X-FDA: 79050973428.21.3561CFA Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf20.hostedemail.com (Postfix) with ESMTP id 356191C0016 for ; Thu, 20 Jan 2022 14:59:14 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 8A24E21906; Thu, 20 Jan 2022 14:59:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1642690752; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DL3B1IO3fZVXuhiBZXzTq6wFq3VQYTl8syynoxUgKjg=; b=FS83u84srngcHTE69hytGOIlMTCDiRWDIztkO2NjkKltuZgh4NWPK4c8t2LMaW/hYlWPff Rqg8rQF+GlsWbtzo60YDAZC07dZP5Qc7iJdi8tlMrGfzhfMBlBm6RqisJulOaA+Ig6gPU0 HeD7ZQv8V+pT8EtOEcoluKk0qACA6Kc= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1642690752; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DL3B1IO3fZVXuhiBZXzTq6wFq3VQYTl8syynoxUgKjg=; b=tyt3IlqYMBdLvexWL/ZRt99q/mP3Kk0FhMjyx0Vpg9KzBMFuvr4MgD8uRPcUgfBSAgk4D8 eeugbMTMda9AVOCw== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 3930A13BCF; Thu, 20 Jan 2022 14:59:12 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id zYZNDcB46WHJLAAAMHmgww (envelope-from ); Thu, 20 Jan 2022 14:59:12 +0000 Message-ID: <807fa53c-6492-52ca-abf3-ce58cc84ca08@suse.cz> Date: Thu, 20 Jan 2022 15:59:11 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v4 63/66] i915: Use the VMA iterator Content-Language: en-US To: Liam Howlett , "maple-tree@lists.infradead.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , Andrew Morton Cc: Song Liu , Davidlohr Bueso , "Paul E . McKenney" , Matthew Wilcox , Laurent Dufour , David Rientjes , Axel Rasmussen , Suren Baghdasaryan , Rik van Riel , Peter Zijlstra , Michel Lespinasse , Jerome Glisse , Minchan Kim , Joel Fernandes , Rom Lemarchand References: <20211201142918.921493-1-Liam.Howlett@oracle.com> <20211201142918.921493-64-Liam.Howlett@oracle.com> From: Vlastimil Babka In-Reply-To: <20211201142918.921493-64-Liam.Howlett@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 356191C0016 X-Stat-Signature: doupn7esjbodhp85j63rxfcfnfe5z9m1 Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=FS83u84s; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b=tyt3IlqY; dmarc=none; spf=pass (imf20.hostedemail.com: domain of vbabka@suse.cz designates 195.135.220.28 as permitted sender) smtp.mailfrom=vbabka@suse.cz X-Rspamd-Server: rspam03 X-HE-Tag: 1642690754-217314 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 12/1/21 15:30, Liam Howlett wrote: > From: "Matthew Wilcox (Oracle)" > > Replace the O(n.log(n)) loop with an O(n) loop. Not true? > Signed-off-by: Matthew Wilcox (Oracle) > Signed-off-by: Liam R. Howlett Acked-by: Vlastimil Babka > --- > drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 14 +++++--------- > 1 file changed, 5 insertions(+), 9 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > index 3173c9f9a040..39960973c130 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c > @@ -425,12 +425,11 @@ static const struct drm_i915_gem_object_ops i915_gem_userptr_ops = { > static int > probe_range(struct mm_struct *mm, unsigned long addr, unsigned long len) > { > - const unsigned long end = addr + len; > + VMA_ITERATOR(vmi, mm, addr); > struct vm_area_struct *vma; > - int ret = -EFAULT; > > mmap_read_lock(mm); > - for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) { > + for_each_vma_range(vmi, vma, addr + len) { > /* Check for holes, note that we also update the addr below */ > if (vma->vm_start > addr) > break; > @@ -438,16 +437,13 @@ probe_range(struct mm_struct *mm, unsigned long addr, unsigned long len) > if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)) > break; > > - if (vma->vm_end >= end) { > - ret = 0; > - break; > - } > - > addr = vma->vm_end; > } > mmap_read_unlock(mm); > > - return ret; > + if (vma) > + return -EFAULT; > + return 0; > } > > /*