From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 53368296BD6; Wed, 8 Oct 2025 06:04:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759903481; cv=none; b=U4/Ib4l2S+4Xd73lHR7u4J3PzAMUSZaVHfbGpUjwqolhVcJlMklp3xHR05BVngp7s6tb8ao5JeXTCKSTf2SDr0h4G7jP3eftN5grHbz97xwkX4sAJI7ldTXHPH0j4uiqyrDfFoFd7Y1jCsTuq2v20aiMIiFjrheH/hXcsiwsZAo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759903481; c=relaxed/simple; bh=9gBVmTr4OaFBiSGVa5HGdTny9W/pM69XwMzDwk/g0u4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XiEG76unIlBD3hI/sG2k5LKR5hi2fAVOPYWuAZMyjd9ogywPDVpm6hFsDUxnh/Dr2svL6etAhOhGdcEJvNLSD3i4X5rhraXQoXsi/Zmx9vQtZ8TNDz4ur+dGgiK+HgpOOPRaud7B1V+9yGKKctq+2/e4GKxqbfxQjmAKC9ECaSQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=xIXq2OjG; arc=none smtp.client-ip=198.137.202.133 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=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="xIXq2OjG" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; 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=9i/hW2gsNIwvxGPBjR3UaQnJZD5u1DTKjwq3K7Rz45A=; b=xIXq2OjG57P+Qt2gk0FH0OvWkK Vd+ovtPhdeofYhBwG6boyowN0XgTdPjAZkmLA2CHdgmhSwYQ1e8LrpkUjOXt63w888HO2idXPbUjv gBFqaY7J7u2OP7puYZ3zvwJLi2fvAEj5w49jTK2iCAZGo20X1snDjfrARFJK0uMI1eo8VkAL3U2iu 5GT1x06quwBEdppdk4fHQGr74EY5fP7bqoICxMgBrISd9jWPTGbQV1105mgcetFA7F0NlekJXo4p1 r07Mk9iSassaNZu6epxkVWDPk2pukrHx2T3EE4odUIXfTvDZeBbu+sz9zi6Y5UVXXqZ6iDFGvJNuk CpBxUrqQ==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1v6NHv-00000003GA6-11Tx; Wed, 08 Oct 2025 06:04:35 +0000 Date: Tue, 7 Oct 2025 23:04:35 -0700 From: Christoph Hellwig To: Vlastimil Babka Cc: Christoph Hellwig , Suren Baghdasaryan , "Liam R. Howlett" , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Uladzislau Rezki , Sidhartha Kumar , linux-mm@kvack.org, linux-kernel@vger.kernel.org, rcu@vger.kernel.org, maple-tree@lists.infradead.org, Alexei Starovoitov , Sebastian Andrzej Siewior , Venkat Rao Bagalkote , Qianfeng Rong , Wei Yang , "Matthew Wilcox (Oracle)" , Andrew Morton , Lorenzo Stoakes , WangYuli , Jann Horn , Pedro Falcato Subject: Re: [PATCH v8 00/23] SLUB percpu sheaves Message-ID: References: <20250910-slub-percpu-caches-v8-0-ca3099d8352c@suse.cz> Precedence: bulk X-Mailing-List: rcu@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: X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Tue, Oct 07, 2025 at 10:03:04AM +0200, Vlastimil Babka wrote: > Basically it's for situations where you have an upper bound on the objects > you might need to allocate in some restricted context where you can't fail > but also can't reclaim etc. The steps are: Ok, so you still need a step where you reserve, which can fail and only after that guarantee you can allocate up to the reservation? I.e. not a replacement for mempools? Just asking because I recently had to implement a mempool_alloc_batch to allow grabbing multiple objects out of a mempool safely for something I'm working on.