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 7FDFF15C131 for ; Wed, 25 Sep 2024 10:12:18 +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=1727259138; cv=none; b=qpWhXsW7sEzXUo+0iXcLBx92h8kUvi+9QKTlqzETQoDdTtOh8WXqf+OOoEQVWNBfAbT0TfwXXXfz1Xwn/n4MrACjyhrlCRyQdDCPsMb7zoWMmSA7SXs3+/et0UoKhhCaIocb6eq9f8oAY3mMNRF0ToKwJGrtdgaMq/tvEjgxqwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727259138; c=relaxed/simple; bh=7bhx9D52JHafJKXD9IOlL6eYKi9gYYK4mEdssxpI6mI=; h=Date:To:From:Subject:Message-Id; b=OTn2DD5n2Nk8yKoBM3bbUntakt7WwzyAQMb3pQ5cjQe1iEGA4hLU1Hs8aR8lUBfDtrJoBvjaIg+fdGAwMXKFmd5z+VdcpJChThwWqQd32Ox+1a5kQZ0BXbEcn/BiethMZRG12t2aI+U5KzjZ8n5KtVQjusZ25jq0exgRazyKZwQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=0PTDtAAp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="0PTDtAAp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECFDEC4CEC3; Wed, 25 Sep 2024 10:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1727259138; bh=7bhx9D52JHafJKXD9IOlL6eYKi9gYYK4mEdssxpI6mI=; h=Date:To:From:Subject:From; b=0PTDtAApZuNSgIOpplCzebAvQDpDyTIAEMfggWLP1V+VPGmWsAuCN0jISwRgZ7gzQ 8UxGET3udJHBnegzYyXpTd/f1ooe7rlqk+coWj7vgxDqmYMRFMynRk1LkuwMQZEyHr qTua9M9nb58VPCy5zmZNBKAYbGS5iIj/Ayv2xngI= Date: Wed, 25 Sep 2024 03:12:17 -0700 To: mm-commits@vger.kernel.org,Liam.Howlett@Oracle.com,richard.weiyang@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + maple_tree-memset-maple_big_node-as-a-whole.patch added to mm-unstable branch Message-Id: <20240925101217.ECFDEC4CEC3@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: maple_tree: memset maple_big_node as a whole has been added to the -mm mm-unstable branch. Its filename is maple_tree-memset-maple_big_node-as-a-whole.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-memset-maple_big_node-as-a-whole.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Wei Yang Subject: maple_tree: memset maple_big_node as a whole Date: Sun, 8 Sep 2024 14:05:54 +0000 In mast_fill_bnode(), we first clear some fields of maple_big_node and set the 'type' unconditionally before return. This means we won't leverage any information in maple_big_node and it is safe to clear the whole structure. In maple_big_node, we define slot and padding/gap in a union. And based on current definition of MAPLE_BIG_NODE_SLOTS/GAPS, padding is always less than slot and part of the gap is overlapped by slot. For example on 64bit system: MAPLE_BIG_NODE_SLOT is 34 MAPLE_BIG_NODE_GAP is 21 With this knowledge, current code may clear some space by twice. And this could be avoid by clearing the structure as a whole. Link: https://lkml.kernel.org/r/20240908140554.20378-3-richard.weiyang@gmail.com Signed-off-by: Wei Yang Reviewed-by: Liam R. Howlett Signed-off-by: Andrew Morton --- lib/maple_tree.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/lib/maple_tree.c~maple_tree-memset-maple_big_node-as-a-whole +++ a/lib/maple_tree.c @@ -3155,10 +3155,7 @@ static inline void mast_fill_bnode(struc bool cp = true; unsigned char split; - memset(mast->bn->gap, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->gap)); - memset(mast->bn->slot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->slot)); - memset(mast->bn->pivot, 0, sizeof(unsigned long) * ARRAY_SIZE(mast->bn->pivot)); - mast->bn->b_end = 0; + memset(mast->bn, 0, sizeof(struct maple_big_node)); if (mte_is_root(mas->node)) { cp = false; _ Patches currently in -mm which might be from richard.weiyang@gmail.com are maple_tree-i-is-always-less-than-or-equal-to-mas_end.patch maple_tree-goto-complete-directly-on-a-pivot-of-0.patch maple_tree-remove-maple_big_nodeparent.patch maple_tree-memset-maple_big_node-as-a-whole.patch