From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C22083176E4; Tue, 10 Feb 2026 16:49:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770742162; cv=none; b=FpC/f4/8iz+dhGqIGnQWEjkhpPl0cfHUF10BHHv72X8EXwOSYm1ECci/71iRb7fzD/7+bxRILs7i0j3woc9LHV+55HzA8U+nOp80/yn6DAEQNaCxTZQKYgGMo1uZl4nkoPE7ozN1SN1bg7DE8E3l2EMyNe+3xSL7NfvvDrF4Aas= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770742162; c=relaxed/simple; bh=qiunUbsKEW7gX0zCCMDrQrvoSAJfNHBqrIU7Es8yzS8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=LI/LO2HcuRdkToOKqLq1yLUOVvnFr0eU9x27aCTNEle/Bu7qfJinzbd/zSov1bPUFl+V5Dtwy3M52XM8f4PT/vZyfjGaN6MbJIDwm1k7O4T2UEghy6E9mUa1MCmcNPi59vuYdYv8K17lHQY90XpP9RsimjwRnryhpBNbJh+/9Fg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=R9vIlW6H; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="R9vIlW6H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27058C116C6; Tue, 10 Feb 2026 16:49:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770742162; bh=qiunUbsKEW7gX0zCCMDrQrvoSAJfNHBqrIU7Es8yzS8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R9vIlW6HRyYc4jDn6t3F8VDRwTUXJ6L2WxDYx1nGhK3O2j9faUFEVV+RmNw8Y/hYC 5HBGHZA7wdLvjS5SbrLzXnbp/DtZbySJdS4J3u+0GRASNNkAOC/cm4fUPgTJVkEDjN TPZZ5BQdL2F8iVKa+RauLwA/aem/K7ZIhZjjvUwZF1GdwqMFkN/DSImphRoNkR+GKx 1LUKL4FM7KR1OJW0viBvkQjPqAvmZTwiTa/4GZRt+zX9eKE1fRujNwnCeMAulHHkSB UG2R/q+s3UN2fi3q2bxBuuiWxUHeXIVQVt/NbWCSuSwqSGK/gs1lC+FEkQ0sFwx7wm TRv0HUkZflnWA== Date: Tue, 10 Feb 2026 17:49:17 +0100 From: Daniel Gomez To: Andreas Hindborg Cc: Tamir Duberstein , Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?B?QmrDtnJu?= Roy Baron , Benno Lossin , Alice Ryhl , Trevor Gross , Danilo Krummrich , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "Matthew Wilcox (Oracle)" Subject: Re: [PATCH v3 11/12] xarray, radix-tree: enable sheaf support for kmem_cache Message-ID: References: <20260209-xarray-entry-send-v3-0-f777c65b8ae2@kernel.org> <20260209-xarray-entry-send-v3-11-f777c65b8ae2@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@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: <20260209-xarray-entry-send-v3-11-f777c65b8ae2@kernel.org> On 2026-02-09 15:38, Andreas Hindborg wrote: > The rust null block driver plans to rely on preloading xarray nodes from > the radix_tree_node_cachep kmem_cache. > > Cc: "Matthew Wilcox (Oracle)" > Signed-off-by: Andreas Hindborg > --- > lib/radix-tree.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/lib/radix-tree.c b/lib/radix-tree.c > index 976b9bd02a1b5..1cf0012b15ade 100644 > --- a/lib/radix-tree.c > +++ b/lib/radix-tree.c > @@ -1598,10 +1598,16 @@ void __init radix_tree_init(void) > BUILD_BUG_ON(RADIX_TREE_MAX_TAGS + __GFP_BITS_SHIFT > 32); > BUILD_BUG_ON(ROOT_IS_IDR & ~GFP_ZONEMASK); > BUILD_BUG_ON(XA_CHUNK_SIZE > 255); > - radix_tree_node_cachep = kmem_cache_create("radix_tree_node", > - sizeof(struct radix_tree_node), 0, > - SLAB_PANIC | SLAB_RECLAIM_ACCOUNT, > - radix_tree_node_ctor); > + > + struct kmem_cache_args args = { > + .ctor = radix_tree_node_ctor, > + .sheaf_capacity = 64, > + }; Is the sheaf_capacity matching the number of slots in an XArray node? If so, this should be bindings::XA_CHUNK_SIZE.