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 CF0EAC433EF for ; Thu, 3 Mar 2022 11:21:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 471B68D0002; Thu, 3 Mar 2022 06:21:10 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 421A88D0001; Thu, 3 Mar 2022 06:21:10 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 310308D0002; Thu, 3 Mar 2022 06:21:10 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0090.hostedemail.com [216.40.44.90]) by kanga.kvack.org (Postfix) with ESMTP id 219928D0001 for ; Thu, 3 Mar 2022 06:21:10 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3F218180A7F7A for ; Thu, 3 Mar 2022 11:21:08 +0000 (UTC) X-FDA: 79202833416.16.4F7A05F Received: from mail-yw1-f176.google.com (mail-yw1-f176.google.com [209.85.128.176]) by imf07.hostedemail.com (Postfix) with ESMTP id 89B3A40008 for ; Thu, 3 Mar 2022 11:21:07 +0000 (UTC) Received: by mail-yw1-f176.google.com with SMTP id 00721157ae682-2dbd8777564so51867177b3.0 for ; Thu, 03 Mar 2022 03:21:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:from:date:message-id:subject:to:cc; bh=lP2eYkn3jCttHpEzQjHtAuLqqZQ4NdZMKDrxiU6dv4U=; b=y8vT8zoGiHPENgs7BRcIeDNUYpJjdneQIFVAungmmew1e6xABHI3J8hDqB5sJWPZBr x+NKrJIRcSY1outii6hvceo9yWSzG9XWWqDk1kZ+vwy7SRnTftKaCykBapcn4znEKd/q gWGlUlXuKwr+jNGSFf3yumvMDRxDJVDXKNR+2ssF0tNIvadwAjCQG/jrGra2nTejoQwu aA8LyowSm0vQV1mXVexJLvp7Skqo4NNmO89V88I9W4okrhOihk5MOXxpsZA66TN5pjYH C6JF014/6Yq7BuvuPgmcpJRmapUaFUwkSu0l0pZ/UQALDZVTDU39F9KRfMV5j0xhIny3 MOsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=lP2eYkn3jCttHpEzQjHtAuLqqZQ4NdZMKDrxiU6dv4U=; b=w3Ty8duBpqpZJuED+/b5SDGU2zd9UXO9yl1drXsQfsrDx6nm5twTV3P+CWIyMWjJlp wm6AKBlUvx2rwTCa1ahF5rRpFws7tGWmH2yaTM1PfraLUGDmNjJ75xxkX+lCqQeEpbcj km5EBCD1iVArEUQhrjdZk7RdGaKKlaGe/5xXCe9X9gnTZb5ufEaJYxJR5DssDPnSokli fmPHDQAwX5iXQQwBx6gQCqn1IDkhiTYJkPiMLGB93+HnbdS0KCFgIUtOIiGo78bPyUix Xf8k4bWPWALm5dlG7hNhCHO1J+R+/ZA8VyKa1s9TjHIYxIxP1c07/hvlDI9r7584FRAy c8zg== X-Gm-Message-State: AOAM533/Sq/WxTv6gOC7PHSt9quRcLYXng57gdWETjo4tBy3qDDxy4hT XBUBkx9boENSPVPOTlI2X2cTU5/TWXZP6I2EutkhwA== X-Google-Smtp-Source: ABdhPJytzDF+rrZxtHvKjlaJhF7+9swMvL6S5G58zt8ipoCmv16tay7Bz/Q2qo19fTvP6FxEqV8CyPZafDDogmlTwc8= X-Received: by 2002:a0d:f9c5:0:b0:2db:7a9a:b01a with SMTP id j188-20020a0df9c5000000b002db7a9ab01amr19596239ywf.458.1646306466738; Thu, 03 Mar 2022 03:21:06 -0800 (PST) MIME-Version: 1.0 From: Muchun Song Date: Thu, 3 Mar 2022 19:20:30 +0800 Message-ID: Subject: Re: [PATCH v2 RESEND 1/2] arm64: avoid flushing icache multiple times on contiguous HugeTLB To: Catalin Marinas Cc: Will Deacon , Andrew Morton , David Hildenbrand , "Bodeddula, Balasubramaniam" , Oscar Salvador , Mike Kravetz , David Rientjes , Mark Rutland , james.morse@arm.com, "Song Bao Hua (Barry Song)" , linux-arm-kernel@lists.infradead.org, LKML , Linux Memory Management List , Xiongchun duan , Fam Zheng , Muchun Song Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: eb3riwh67zoyt9egkn8rkao3hjumwnjp Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=y8vT8zoG; spf=pass (imf07.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.128.176 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com; dmarc=pass (policy=none) header.from=bytedance.com X-Rspamd-Queue-Id: 89B3A40008 X-HE-Tag: 1646306467-116915 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 Wed, Mar 2, 2022 at 8:32 PM Catalin Marinas wrote: > > On Wed, Mar 02, 2022 at 04:46:23PM +0800, Muchun Song wrote: > > When a contiguous HugeTLB page is mapped, set_pte_at() will be called > > CONT_PTES/CONT_PMDS times. Therefore, __sync_icache_dcache() will > > flush cache multiple times if the page is executable (to ensure > > the I-D cache coherency). However, the first flushing cache already > > covers subsequent cache flush operations. So only flusing cache > > for the head page if it is a HugeTLB page to avoid redundant cache > > flushing. In the next patch, it is also depends on this change > > since the tail vmemmap pages of HugeTLB is mapped with read-only > > meanning only head page struct can be modified. > > > > Signed-off-by: Muchun Song > > Reviewed-by: Catalin Marinas Thanks for your review. > > (for this patch only, I have yet to figure out whether Anshuman's and > Mark's comments have been addressed in patch 2) > Their comments are memory hotplug related, actually, those issues are not real issues as I explained in patch 2. And If you have any questions, feel free to ask, maybe I can help. Thanks Catalin.