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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 353DBC3B188 for ; Thu, 13 Feb 2020 02:41:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E75E620873 for ; Thu, 13 Feb 2020 02:41:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="X7Jcr6NS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E75E620873 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9CE566B04FD; Wed, 12 Feb 2020 21:41:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 97EB16B04FE; Wed, 12 Feb 2020 21:41:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 893716B04FF; Wed, 12 Feb 2020 21:41:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 725366B04FD for ; Wed, 12 Feb 2020 21:41:18 -0500 (EST) Received: from smtpin27.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 38CBE442B for ; Thu, 13 Feb 2020 02:41:18 +0000 (UTC) X-FDA: 76483552236.27.mask44_629b5c855ee48 X-HE-Tag: mask44_629b5c855ee48 X-Filterd-Recvd-Size: 4846 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf32.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Feb 2020 02:41:17 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 782A1206ED; Thu, 13 Feb 2020 02:41:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1581561676; bh=0t6KHIJuCawpks8f0YEOVMRHbrFZCNj0rrv490GW5l4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=X7Jcr6NSTwsp7aZfdB0TzJLVP+baZ7s1+HWyJGhnsJx2iGOh06dXPcbQAiuA7R5ZX MiAU46cdqwjcIxNtid0j06sUYiHU6KPJJYnSt7lRZya+seM5nwOKtWPvS01BuoMMOW Z3KvqqZV2sH071rmlNFpZNSXyWxJm/5H1m8pFmm8= Date: Wed, 12 Feb 2020 18:41:15 -0800 From: Andrew Morton To: Arjun Roy Cc: davem@davemloft.net, netdev@vger.kernel.org, linux-mm@kvack.org, arjunroy@google.com, Eric Dumazet , Soheil Hassas Yeganeh Subject: Re: [PATCH resend mm,net-next 1/3] mm: Refactor insert_page to prepare for batched-lock insert. Message-Id: <20200212184115.127c17c6b0f9dab6fcae56c2@linux-foundation.org> In-Reply-To: <20200128025958.43490-1-arjunroy.kdev@gmail.com> References: <20200128025958.43490-1-arjunroy.kdev@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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 Mon, 27 Jan 2020 18:59:56 -0800 Arjun Roy wrote: > Add helper methods for vm_insert_page()/insert_page() to prepare for > vm_insert_pages(), which batch-inserts pages to reduce spinlock > operations when inserting multiple consecutive pages into the user > page table. > > The intention of this patch-set is to reduce atomic ops for > tcp zerocopy receives, which normally hits the same spinlock multiple > times consecutively. I tweaked this a bit for the addition of page_has_type() to insert_page(). Please check. From: Arjun Roy Subject: mm: Refactor insert_page to prepare for batched-lock insert. From: Arjun Roy Add helper methods for vm_insert_page()/insert_page() to prepare for vm_insert_pages(), which batch-inserts pages to reduce spinlock operations when inserting multiple consecutive pages into the user page table. The intention of this patch-set is to reduce atomic ops for tcp zerocopy receives, which normally hits the same spinlock multiple times consecutively. Link: http://lkml.kernel.org/r/20200128025958.43490-1-arjunroy.kdev@gmail.com Signed-off-by: Arjun Roy Signed-off-by: Eric Dumazet Signed-off-by: Soheil Hassas Yeganeh Signed-off-by: Andrew Morton --- mm/memory.c | 39 ++++++++++++++++++++++++--------------- 1 file changed, 24 insertions(+), 15 deletions(-) --- a/mm/memory.c~mm-refactor-insert_page-to-prepare-for-batched-lock-insert +++ a/mm/memory.c @@ -1430,6 +1430,27 @@ pte_t *__get_locked_pte(struct mm_struct return pte_alloc_map_lock(mm, pmd, addr, ptl); } +static int validate_page_before_insert(struct page *page) +{ + if (PageAnon(page) || PageSlab(page) || page_has_type(page)) + return -EINVAL; + flush_dcache_page(page); + return 0; +} + +static int insert_page_into_pte_locked(struct mm_struct *mm, pte_t *pte, + unsigned long addr, struct page *page, pgprot_t prot) +{ + if (!pte_none(*pte)) + return -EBUSY; + /* Ok, finally just insert the thing.. */ + get_page(page); + inc_mm_counter_fast(mm, mm_counter_file(page)); + page_add_file_rmap(page, false); + set_pte_at(mm, addr, pte, mk_pte(page, prot)); + return 0; +} + /* * This is the old fallback for page remapping. * @@ -1445,26 +1466,14 @@ static int insert_page(struct vm_area_st pte_t *pte; spinlock_t *ptl; - retval = -EINVAL; - if (PageAnon(page) || PageSlab(page) || page_has_type(page)) + retval = validate_page_before_insert(page); + if (retval) goto out; retval = -ENOMEM; - flush_dcache_page(page); pte = get_locked_pte(mm, addr, &ptl); if (!pte) goto out; - retval = -EBUSY; - if (!pte_none(*pte)) - goto out_unlock; - - /* Ok, finally just insert the thing.. */ - get_page(page); - inc_mm_counter_fast(mm, mm_counter_file(page)); - page_add_file_rmap(page, false); - set_pte_at(mm, addr, pte, mk_pte(page, prot)); - - retval = 0; -out_unlock: + retval = insert_page_into_pte_locked(mm, pte, addr, page, prot); pte_unmap_unlock(pte, ptl); out: return retval; _