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 7502AECAAD3 for ; Fri, 9 Sep 2022 04:26:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9A60E8D0003; Fri, 9 Sep 2022 00:26:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 956208D0002; Fri, 9 Sep 2022 00:26:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86B7C8D0003; Fri, 9 Sep 2022 00:26:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 784828D0002 for ; Fri, 9 Sep 2022 00:26:34 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 4E85940424 for ; Fri, 9 Sep 2022 04:26:34 +0000 (UTC) X-FDA: 79891260708.14.7674D72 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf05.hostedemail.com (Postfix) with ESMTP id E636B10008B for ; Fri, 9 Sep 2022 04:26:33 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7C014153B; Thu, 8 Sep 2022 21:26:39 -0700 (PDT) Received: from [10.162.41.8] (unknown [10.162.41.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3D5263F71A; Thu, 8 Sep 2022 21:26:23 -0700 (PDT) Message-ID: Date: Fri, 9 Sep 2022 09:56:21 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v3 1/4] Revert "Documentation/features: mark BATCHED_UNMAP_TLB_FLUSH doesn't apply to ARM64" Content-Language: en-US To: Yicong Yang , akpm@linux-foundation.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, catalin.marinas@arm.com, will@kernel.org, linux-doc@vger.kernel.org Cc: corbet@lwn.net, peterz@infradead.org, arnd@arndb.de, linux-kernel@vger.kernel.org, darren@os.amperecomputing.com, yangyicong@hisilicon.com, huzhanyuan@oppo.com, lipeifeng@oppo.com, zhangshiming@oppo.com, guojian@oppo.com, realmz6@gmail.com, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, Barry Song <21cnbao@gmail.com>, wangkefeng.wang@huawei.com, xhao@linux.alibaba.com, prime.zeng@hisilicon.com, Barry Song References: <20220822082120.8347-1-yangyicong@huawei.com> <20220822082120.8347-2-yangyicong@huawei.com> From: Anshuman Khandual In-Reply-To: <20220822082120.8347-2-yangyicong@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com; dmarc=pass (policy=none) header.from=arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1662697594; a=rsa-sha256; cv=none; b=3yFzBVmOnyeE9teYXY5y4ona6VTMs40iaD9HFqayjo6qLJu1krNkxf7Z8kyIGdVvHHhOXq WISEIOGNj9nn96q4BNwp3/rjPLFbQv3nEwKhf1SCx1EHsBaO354+9tURmgRjpmQRRBBlXi Bmps2J1g1FkJTJxxRUQ+pZS8AMGGw7I= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1662697594; 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=oxmqCxXmNigtdRWz5xjZpTe5qIvI0404SOXifO7fVWc=; b=AE6yaExtaw6lX0rLsO/4uyqjA7xHcxeGLVOScI9c+mnhSsvs1zka+hlU3M02kTVnHaQSAh 1+Q+ZPMZ7ooqYnI3bpbnTl5v7YO31OavlvtNvq1j3+oBZUQG6Hn8Xwg7g8VYZRjlv+qfu5 0qZVwFMEha2Qg+5Frxo8+kgjs8JYS84= X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: E636B10008B Authentication-Results: imf05.hostedemail.com; dkim=none; spf=pass (imf05.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com; dmarc=pass (policy=none) header.from=arm.com X-Stat-Signature: 941qyhbjxmr4ziru64o3ndxmam56ksmy X-Rspam-User: X-HE-Tag: 1662697593-618209 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 8/22/22 13:51, Yicong Yang wrote: > From: Barry Song > > This reverts commit 6bfef171d0d74cb050112e0e49feb20bfddf7f42. > > I was wrong. Though ARM64 has hardware TLB flush, but it is not free > and it is still expensive. > We still have a good chance to enable batched and deferred TLB flush > on ARM64 for memory reclamation. A possible way is that we only queue > tlbi instructions in hardware's queue. When we have to broadcast TLB, > we broadcast it by dsb. We just need to get adapted the existing > BATCHED_UNMAP_TLB_FLUSH. > > Tested-by: Xin Hao > Signed-off-by: Barry Song > Signed-off-by: Yicong Yang > --- > Documentation/features/arch-support.txt | 1 - > Documentation/features/vm/TLB/arch-support.txt | 2 +- > 2 files changed, 1 insertion(+), 2 deletions(-) > > diff --git a/Documentation/features/arch-support.txt b/Documentation/features/arch-support.txt > index 118ae031840b..d22a1095e661 100644 > --- a/Documentation/features/arch-support.txt > +++ b/Documentation/features/arch-support.txt > @@ -8,5 +8,4 @@ The meaning of entries in the tables is: > | ok | # feature supported by the architecture > |TODO| # feature not yet supported by the architecture > | .. | # feature cannot be supported by the hardware > - | N/A| # feature doesn't apply to the architecture > > diff --git a/Documentation/features/vm/TLB/arch-support.txt b/Documentation/features/vm/TLB/arch-support.txt > index 039e4e91ada3..1c009312b9c1 100644 > --- a/Documentation/features/vm/TLB/arch-support.txt > +++ b/Documentation/features/vm/TLB/arch-support.txt > @@ -9,7 +9,7 @@ > | alpha: | TODO | > | arc: | TODO | > | arm: | TODO | > - | arm64: | N/A | > + | arm64: | TODO | > | csky: | TODO | > | hexagon: | TODO | > | ia64: | TODO | I believe this patch is not needed, which explicitly reverts an older commit. Instead when ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH framework gets enabled on arm64, the same patch could just drop 'NA' as possible values for arch support for a give feature in file Documentation/features/arch-support.txt.