From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 58EBF1F0E25 for ; Mon, 16 Jun 2025 14:50:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750085427; cv=none; b=sQZdhTyr5NPOHEYQHQv/YtCIZxbDCK8UAHQ+W/J4QXlpIAr5W8chyaAvFLpXKma6nxzNnZuNNjiJpslALMNyYFrw9qTFC2938/kSTLF7MFLuRaK4JTjLqQ9zp9/i8Y1VgIcl7nD4bQ/ph/Tt/xFsAd/KhcX1bH10PXCVUHUcDII= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750085427; c=relaxed/simple; bh=NLHb6i+qfakh3m/2nUmEanwAnL7MqTRL1fFLISGJsfE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HFC6bYUD5ks4+clTqRC97ulw0vuY2Red2YZnW4zNuk24fa/awp0+oGT0/xpyozO0XNsCv0UtjbHFDPLgaYF7yWnmo0dErCD3GcdniJVUb+noEpZw1BplsHVQbbaVXE4cAlfG7i/q27OFs2vDVCr5oVwXXE5oFcWGNqpQ28XtN+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=IJ6JZT0d; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="IJ6JZT0d" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=NLHb6i+qfakh3m/2nUmEanwAnL7MqTRL1fFLISGJsfE=; b=IJ6JZT0dcI9doVtkpQ1MU4ZIRg HXgnl/4XnBwbXVkR+gur94H1RK5EM/DErrK8zGCZkO/Vsjk6xqEQ3RN+Grv4GITduD+mGVA6ocBfg EWylcsKgU4aTBT19cT1mSo9Lvhagpt3GkUlm/wkhp3cwKIMvnOeroe+Flz3Hi+NZaHzoS6RC1wRzH 233FNkwRk+POciJSuvtLmRzwHLIOXtaif6PvbisOoHRoDF1/+4ycsvnaEi1wctOQNf+37L6nATdYN GnfV6d9EDonlWPgTSWH3c7GQSm9IDYCSfGu5V29rVYDKu8oURAoBwXNdSnvdUdzrLfHczqOrNPGRh BfVe3H0Q==; Received: from 2001-1c00-8d82-d000-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d82:d000:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1uRBA2-00000003cLU-0Als; Mon, 16 Jun 2025 14:50:10 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 4255930D552; Mon, 16 Jun 2025 16:50:07 +0200 (CEST) Date: Mon, 16 Jun 2025 16:50:07 +0200 From: Peter Zijlstra To: Dave Hansen Cc: Ankur Arora , linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, mjguzik@gmail.com, luto@kernel.org, acme@kernel.org, namhyung@kernel.org, tglx@linutronix.de, willy@infradead.org, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com Subject: Re: [PATCH v4 13/13] x86/folio_zero_user: Add multi-page clearing Message-ID: <20250616145007.GF1613376@noisy.programming.kicks-ass.net> References: <20250616052223.723982-1-ankur.a.arora@oracle.com> <20250616052223.723982-14-ankur.a.arora@oracle.com> <1c0d3994-1397-4bc6-bb55-9c26acdcb477@intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1c0d3994-1397-4bc6-bb55-9c26acdcb477@intel.com> On Mon, Jun 16, 2025 at 07:44:13AM -0700, Dave Hansen wrote: > To me, that's deserving of an ARCH_HAS_FOO bit that we can set on the > x86 side that then cajoles the core mm/ code to use the fancy new > clear_pages_resched() implementation. Note that we should only set this bit with either full or lazy preemption selected. Haven't checked the patch-set to see if that constraint is already taken care of.