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 660FEC3F6B0 for ; Wed, 24 Aug 2022 09:40:25 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id BC04C940008; Wed, 24 Aug 2022 05:40:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B7048940007; Wed, 24 Aug 2022 05:40:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A5F07940008; Wed, 24 Aug 2022 05:40:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 984A2940007 for ; Wed, 24 Aug 2022 05:40:24 -0400 (EDT) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6C60A16096E for ; Wed, 24 Aug 2022 09:40:24 +0000 (UTC) X-FDA: 79833990768.02.A2367B3 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf21.hostedemail.com (Postfix) with ESMTP id A8B501C0045 for ; Wed, 24 Aug 2022 09:40:22 +0000 (UTC) Received: from dggpemm500021.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MCLcR2060znTkv; Wed, 24 Aug 2022 17:37:59 +0800 (CST) Received: from dggpemm500001.china.huawei.com (7.185.36.107) by dggpemm500021.china.huawei.com (7.185.36.109) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 24 Aug 2022 17:40:08 +0800 Received: from [10.174.177.243] (10.174.177.243) by dggpemm500001.china.huawei.com (7.185.36.107) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 24 Aug 2022 17:40:06 +0800 Message-ID: <0dc19773-81f7-84c2-2bc7-7d8d987b24b7@huawei.com> Date: Wed, 24 Aug 2022 17:40:06 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH v3 2/4] mm/tlbbatch: Introduce arch_tlbbatch_should_defer() Content-Language: en-US To: Yicong Yang , , , , , , , CC: , , , , , , , , , , , , , , , , Barry Song <21cnbao@gmail.com>, , , , Anshuman Khandual References: <20220822082120.8347-1-yangyicong@huawei.com> <20220822082120.8347-3-yangyicong@huawei.com> From: Kefeng Wang In-Reply-To: <20220822082120.8347-3-yangyicong@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.243] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To dggpemm500001.china.huawei.com (7.185.36.107) X-CFilter-Loop: Reflected ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661334023; h=from:from:sender:reply-to:subject:subject: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=PxS15Xs54z0xH/Nw8Dq43fMRQXfoHi/EmUm6dEc7q8k=; b=OhNGzVPvhOjoA432H7WjvPHSSd33EMxSkmPM4gDtFbi/kwVKnQ3BvRBzGek39QKhkmdbDj obiIF+4ZixzUYj2I8YbPnXrxFsZWDy+6Yva5yWxecjxdP6NtWyIXdLv1t3e6ScAPGwNoBE 6yCdDNmNGeUqaMLgwX2sBTLhq+lP+6M= ARC-Authentication-Results: i=1; imf21.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf21.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661334023; a=rsa-sha256; cv=none; b=nAqLsWWEFRWfrrEuKWRgngVN6kOrM7iR7byTrDZx1VqZrgUCRmf2zN9Mn2cAfsrt5+o+JR /k11oi2vfTf2gtI/aBG1ROOP3dSUBnhq1OV3HpH/nv1dJfNgwE5P4d8yMVsY9TkMeUnR2X 2Fy0rNug0qKD2Hs3mZYqOVSOkaiQccc= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: A8B501C0045 X-Rspam-User: Authentication-Results: imf21.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf21.hostedemail.com: domain of wangkefeng.wang@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=wangkefeng.wang@huawei.com X-Stat-Signature: zrasn596mqd886artxcnymhzrkdiquyc X-HE-Tag: 1661334022-372804 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 2022/8/22 16:21, Yicong Yang wrote: > From: Anshuman Khandual > > The entire scheme of deferred TLB flush in reclaim path rests on the > fact that the cost to refill TLB entries is less than flushing out > individual entries by sending IPI to remote CPUs. But architecture > can have different ways to evaluate that. Hence apart from checking > TTU_BATCH_FLUSH in the TTU flags, rest of the decision should be > architecture specific. > > Signed-off-by: Anshuman Khandual > [https://lore.kernel.org/linuxppc-dev/20171101101735.2318-2-khandual@linux.vnet.ibm.com/] > Signed-off-by: Yicong Yang > [Rebase and fix incorrect return value type] Reviewed-by: Kefeng Wang > --- > arch/x86/include/asm/tlbflush.h | 12 ++++++++++++ > mm/rmap.c | 9 +-------- > 2 files changed, 13 insertions(+), 8 deletions(-) > > diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h > index cda3118f3b27..8a497d902c16 100644 > --- a/arch/x86/include/asm/tlbflush.h > +++ b/arch/x86/include/asm/tlbflush.h > @@ -240,6 +240,18 @@ static inline void flush_tlb_page(struct vm_area_struct *vma, unsigned long a) > flush_tlb_mm_range(vma->vm_mm, a, a + PAGE_SIZE, PAGE_SHIFT, false); > } > > +static inline bool arch_tlbbatch_should_defer(struct mm_struct *mm) > +{ > + bool should_defer = false; > + > + /* If remote CPUs need to be flushed then defer batch the flush */ > + if (cpumask_any_but(mm_cpumask(mm), get_cpu()) < nr_cpu_ids) > + should_defer = true; > + put_cpu(); > + > + return should_defer; > +} > + > static inline u64 inc_mm_tlb_gen(struct mm_struct *mm) > { > /* > diff --git a/mm/rmap.c b/mm/rmap.c > index edc06c52bc82..a17a004550c6 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -687,17 +687,10 @@ static void set_tlb_ubc_flush_pending(struct mm_struct *mm, bool writable) > */ > static bool should_defer_flush(struct mm_struct *mm, enum ttu_flags flags) > { > - bool should_defer = false; > - > if (!(flags & TTU_BATCH_FLUSH)) > return false; > > - /* If remote CPUs need to be flushed then defer batch the flush */ > - if (cpumask_any_but(mm_cpumask(mm), get_cpu()) < nr_cpu_ids) > - should_defer = true; > - put_cpu(); > - > - return should_defer; > + return arch_tlbbatch_should_defer(mm); > } > > /*