From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 679AF207A20 for ; Tue, 24 Feb 2026 02:06:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771898799; cv=none; b=kVfNjgTrXei+8hhExUXW7thRV2d9zPHqYKzd/zkJQes1r5GBvHJ7/66jImWNLe9XFRD3eFkEJ15RrnjGxaOtD5SOCqJj0ikFhk72CFRZbQTLXxuOoXbtSfXx2G4Wa/LNZ29toap47QZ7zkxM+0h+YO1G6c6SdQnC+F1zlIHFkKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771898799; c=relaxed/simple; bh=9cmN57YEF/nHPX0nb+nzMP1y9QEZjX8MK7/oUFRKFeE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RSnPuUfh7/EFwa23BJPxvu594RcQ1IrOM9P2ofH4fOMPFbEf6WmgJYhiXkM3D5kVJ3EmejMVPtSvnEv7RBxsrRSY7OfbRs/x08/ZZX7QlgqKMYnFD5pNaCDlBQ4NCNZnOpq7OUp6Rf5pD3TAytwquu1kY21poaxAQyDHxfyxTP0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=G0ds5akF; arc=none smtp.client-ip=95.215.58.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="G0ds5akF" 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 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 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.