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 B84881C294; Wed, 3 Jan 2024 17:14:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xNcPVwjh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1ECBDC433C7; Wed, 3 Jan 2024 17:14:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1704302071; bh=E4fQMDUf5orl6WL+46VduCunoxX5GyOCo3YCG6uEpAE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xNcPVwjh0KrHs1ND+721trxN7zJvB02JwJRddYbtOpthec0DZhF+Efja9hZxuPYLs ivo8B8lBdD2J4ymsj5iWlzqyQwbwSjJDyVeHe3CBLdGISB0KCmbiPWHaJ7b0dq+L1y LlQhxqTrzf5TBmg/7JSMf91Lj8Nc8MWNdYoIG5+A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sidhartha Kumar , "Liam R. Howlett" , "Matthew Wilcox (Oracle)" , Peng Zhang , Andrew Morton Subject: [PATCH 6.6 37/49] maple_tree: do not preallocate nodes for slot stores Date: Wed, 3 Jan 2024 17:55:57 +0100 Message-ID: <20240103164840.753225160@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240103164834.970234661@linuxfoundation.org> References: <20240103164834.970234661@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sidhartha Kumar commit 4249f13c11be8b8b7bf93204185e150c3bdc968d upstream. mas_preallocate() defaults to requesting 1 node for preallocation and then ,depending on the type of store, will update the request variable. There isn't a check for a slot store type, so slot stores are preallocating the default 1 node. Slot stores do not require any additional nodes, so add a check for the slot store case that will bypass node_count_gfp(). Update the tests to reflect that slot stores do not require allocations. User visible effects of this bug include increased memory usage from the unneeded node that was allocated. Link: https://lkml.kernel.org/r/20231213205058.386589-1-sidhartha.kumar@oracle.com Fixes: 0b8bb544b1a7 ("maple_tree: update mas_preallocate() testing") Signed-off-by: Sidhartha Kumar Cc: Liam R. Howlett Cc: Matthew Wilcox (Oracle) Cc: Peng Zhang Cc: [6.6+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- lib/maple_tree.c | 11 +++++++++++ tools/testing/radix-tree/maple.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index bb24d84a4922..684689457d77 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5501,6 +5501,17 @@ int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp) mas_wr_end_piv(&wr_mas); node_size = mas_wr_new_end(&wr_mas); + + /* Slot store, does not require additional nodes */ + if (node_size == wr_mas.node_end) { + /* reuse node */ + if (!mt_in_rcu(mas->tree)) + return 0; + /* shifting boundary */ + if (wr_mas.offset_end - mas->offset == 1) + return 0; + } + if (node_size >= mt_slots[wr_mas.type]) { /* Split, worst case for now. */ request = 1 + mas_mt_height(mas) * 2; diff --git a/tools/testing/radix-tree/maple.c b/tools/testing/radix-tree/maple.c index e5da1cad70ba..76a8990bb14e 100644 --- a/tools/testing/radix-tree/maple.c +++ b/tools/testing/radix-tree/maple.c @@ -35538,7 +35538,7 @@ static noinline void __init check_prealloc(struct maple_tree *mt) MT_BUG_ON(mt, mas_preallocate(&mas, ptr, GFP_KERNEL) != 0); allocated = mas_allocated(&mas); height = mas_mt_height(&mas); - MT_BUG_ON(mt, allocated != 1); + MT_BUG_ON(mt, allocated != 0); mas_store_prealloc(&mas, ptr); MT_BUG_ON(mt, mas_allocated(&mas) != 0); -- 2.43.0