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 AAE03226CF6 for ; Thu, 19 Feb 2026 15:17:53 +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=1771514274; cv=none; b=q1E7k3joYKh7noczCASgB2ikT/n2a1y2VETCan9CotbN0vXblzRYPl6k4MHNGAnilCLRxTZHyYzX4YUMoytxdXpYD8pn790FKd8ecmfKGq/N4XynWeWBG7ji3MkDpjDFHwJm54wQnRF9z3BR/NP1DG247B9JInMV7RJE17HzTA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771514274; c=relaxed/simple; bh=RKF1ZWUnRUusApTZZ4jD8FKm6p/YWmJI/un7TOQMghg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hnOJa5AOfUU55UnXGCrJUEItJJ8QjbpZyEfp8t+t+0omPVBqacDPqfSBvc+B4epK+aUCs8DuDRvKTcqdCiyp6AmW58XP+EEf5aDXG9bx1g+dCJRiZN9/y8bVJK6SoOCSn2MA/qEshlvMbh1sqiAwqJ5OPKkc6XAMfWJLQmtK7jU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=gslqVXS/; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="gslqVXS/" 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=uCjIAKqryddsHbFGalV/RlHhxKplrqjevsHUZi32Bao=; b=gslqVXS/BOf1Ra4BuCed6sP0Ff SiZ6o0RIHtLX4h2MAnbUnjj9q323CIKTSi3BB1M/lSGllO6ff8KRj7cI07aVVY2GXJR5N10ZAf5vu bNRxKJY6Ofaejsqhr+SmnIwWkR6zzfE7GBCZcdaW0d1L0VokcN2NgqqjiYkk4R1SqJMX/KltNsESm sbvl8E9aQQA5NcSa6biLGr63OvCqfXRWGRWgL2IxX/R1Xb9nd2CGTPRb95dFbEBEOw6tNTqP3H6hp 6YFAFDIX7l4SD10C4xhKhfu40nZVld9FlDRNvroVQmVaWtMQPwn+zJm3nhwgXsVHDILgKDNc4azPD Po0/MOCQ==; Received: from 2001-1c00-8d85-5700-266e-96ff-fe07-7dcc.cable.dynamic.v6.ziggo.nl ([2001:1c00:8d85:5700:266e:96ff:fe07:7dcc] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vt5mV-00000001RgU-0FtL; Thu, 19 Feb 2026 15:17:31 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id B29DA30075B; Thu, 19 Feb 2026 16:17:29 +0100 (CET) Date: Thu, 19 Feb 2026 16:17:29 +0100 From: Peter Zijlstra To: Kiryl Shutsemau Cc: lsf-pc@lists.linux-foundation.org, linux-mm@kvack.org, x86@kernel.org, linux-kernel@vger.kernel.org, Andrew Morton , David Hildenbrand , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Matthew Wilcox , Johannes Weiner , Usama Arif Subject: Re: [LSF/MM/BPF TOPIC] 64k (or 16k) base page size on x86 Message-ID: <20260219151729.GK1282955@noisy.programming.kicks-ass.net> References: 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: On Thu, Feb 19, 2026 at 03:08:51PM +0000, Kiryl Shutsemau wrote: > No, there's no new hardware (that I know of). I want to explore what page size > means. > > The kernel uses the same value - PAGE_SIZE - for two things: > > - the order-0 buddy allocation size; > > - the granularity of virtual address space mapping; > > I think we can benefit from separating these two meanings and allowing > order-0 allocations to be larger than the virtual address space covered by a > PTE entry. Didn't AA do this a decade ago or somesuch?