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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2405CEFB7E4 for ; Tue, 24 Feb 2026 02:06:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 40D8C6B0095; Mon, 23 Feb 2026 21:06:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3BB666B0096; Mon, 23 Feb 2026 21:06:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2C70E6B0098; Mon, 23 Feb 2026 21:06:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 17E0F6B0095 for ; Mon, 23 Feb 2026 21:06:32 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id B6153B8DA5 for ; Tue, 24 Feb 2026 02:06:31 +0000 (UTC) X-FDA: 84477710982.24.7270073 Received: from out-170.mta1.migadu.com (out-170.mta1.migadu.com [95.215.58.170]) by imf14.hostedemail.com (Postfix) with ESMTP id B847F100006 for ; Tue, 24 Feb 2026 02:06:28 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=G0ds5akF; spf=pass (imf14.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.170 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1771898790; 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:dkim-signature; bh=pGujA8hS1VQqUbv75LvcnfS357Yi5nLYG7BGVulGCoI=; b=gCOha2Ssjgtq1eKCbAiPmP263RYzbOjmEP3pgsTgOBU59VgKASxfvQS03lhYKUKQM+eCLa LK0FkYT4hBFZbsSdDYqF/orNCInhjMUBX2e9wX+Xj0T7ALBmmkV0NQ7k1/5nSaocGt4khs T5wyqXJFOpKR9oeZvdI8u8vfYiNv/Sc= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=G0ds5akF; spf=pass (imf14.hostedemail.com: domain of lance.yang@linux.dev designates 95.215.58.170 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1771898790; a=rsa-sha256; cv=none; b=HaaB9FoqJ7KG/0TZ1/jEnhPt3m0Ov8KyOKGPUJxXDII7GPA9yUtm4BYb0DyT75e459HrLp fVh3i1SgqnRdd1KX8xhUZhD3jRNjG1V3ySesx9sWsF9UCkSeafFeqPHJnthXbLaSV7f5XW OMX+Z4GQ2t/jJNv2etUE8nmDbkAY9Zg= Message-ID: <26ffb92e-1e62-4e1a-b31b-465a882c2ec4@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1771898786; h=from:from: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=pGujA8hS1VQqUbv75LvcnfS357Yi5nLYG7BGVulGCoI=; b=G0ds5akFrIA0kgIZ2TZoxRkmowm+ZNSacUP47Irv3kLMysJFvnDZftaxaHKh2dE6U+NnpP 7ZFsSIjaM4xzt/2/0qIRBSqHS9pHEfEftOm+ah+xqpMHoIjm7AHkAfNJnJz3lG19xt0g/w ncDUJzbnENjBnHnqWzlDZ1arS7Cqw9g= Date: Tue, 24 Feb 2026 10:06:13 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 1/1] mm/mmu_gather: replace IPI with synchronize_rcu() when batch allocation fails To: Dave Hansen Cc: akpm@linux-foundation.org, aneesh.kumar@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, npiggin@gmail.com, peterz@infradead.org, will@kernel.org, david@kernel.org References: <2a6c4e62-1663-4a98-9adc-406a6a1ebfd3@kernel.org> <20260223125826.28207-1-lance.yang@linux.dev> <1373db93-3977-425f-ad59-5970e7e50b48@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Stat-Signature: r6ddedygro7pzcrjb3hx6ad3hdnts8nx X-Rspam-User: X-Rspamd-Queue-Id: B847F100006 X-Rspamd-Server: rspam01 X-HE-Tag: 1771898788-916499 X-HE-Meta: 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 Z8HeWfme M7mMiPJb9Rqt+cFBiGg6ymw7afcKozo7voXsz3pYoauW7RHfydavGxwxg3OINbhjiD5gMBmPkmTeoz0s6erTkd1o6YwRwWhfxuYYHtdmLkjvW8DT1AjQF1RZfd42s/VTluXmU5shYZNw2b96+eLkwSjf3CZXSwDzMDRcdbWh7TamQ+vDeUcRRpjm2peP4oZ52+fi7vKvsxyvW2VDL01kt2HxKik7j+eVL7fTCcEyJHfkh+OPlvpkDL8uEUkcPVvkknD1VElMhfspvuURcJnhD+8S9hw== 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: List-Subscribe: List-Unsubscribe: On 2026/2/24 00:35, Dave Hansen wrote: > On 2/23/26 08:29, Lance Yang wrote: >> >> Note: Use this when code really needs to wait for synchronization, >> *not* for freeing memory. Memory freeing should use RCU callbacks >> that don't cause latency spikes in this thread. > > Yeah, but I'd probably mix it in with the other chit chat about > non-atomic contexts. I'd also make it something like: > > Do not use for freeing memory. Use RCU callbacks instead to > avoid latency spikes. > > to make the commands clear. Got it, thanks. I'll update it in v2.