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 3CEB923A115; Tue, 14 Jan 2025 06:42:45 +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=1736836965; cv=none; b=j9f+KlisY9SSA2xkDJ0KXux90wSGPMzUoqXOP6LiqCmym64+FM9tiKlQZPqQiuOJOZ3FRwkqBoPaju2wjSQ5pmtkR9beVPESdF/rCGlTAOvufkpLDEQglITM0sUotgIN4MTuYEUQC6L1suWATLNAcXHGyDsoylZQZ8bj8oL4SFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736836965; c=relaxed/simple; bh=cxjl2dKQjE2T3sE0Qk8Ni909AJcdJRbX8+4XuwMcNe0=; h=Date:To:From:Subject:Message-Id; b=ESLPRepSC59Zv0vs6UGsuyBcHMlGgNHe69u1ZnnIXsSoq0ZfZy+3+uU3YIJTt2ke8c8LqjHSaa3Eq7tNqM0TFtkRwNam0EiLTEPE5cqbj2f20ZUI0kbvIuaELuxUrm5pTQ4NcRlFzF709iY/7wrt3jGSBMogY+R31vLkSFfLtVM= 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=Y+DINK9L; 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="Y+DINK9L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10459C4CEDD; Tue, 14 Jan 2025 06:42:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1736836965; bh=cxjl2dKQjE2T3sE0Qk8Ni909AJcdJRbX8+4XuwMcNe0=; h=Date:To:From:Subject:From; b=Y+DINK9L7KgV48bNkqIVKMzkSlZl/a3kOuTUjX7Hs63UXZeBUdRw0rSNZeIZJ+15V WyRN0WPTEMirI5QsqpF6A1xBhN2rt25OjA7pwL1/Gyu7niwBWStclikmLPVLbYHs1v qMsmeCmYS3OwL3HHXl8nfD9L79AWVPSKbTdrbSB8= Date: Mon, 13 Jan 2025 22:42:44 -0800 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sidhartha.kumar@oracle.com,lorenzo.stoakes@oracle.com,Liam.Howlett@Oracle.com,richard.weiyang@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] maple_tree-simplify-split-calculation.patch removed from -mm tree Message-Id: <20250114064245.10459C4CEDD@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: maple_tree: simplify split calculation has been removed from the -mm tree. Its filename was maple_tree-simplify-split-calculation.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Wei Yang Subject: maple_tree: simplify split calculation Date: Wed, 13 Nov 2024 03:16:14 +0000 Patch series "simplify split calculation", v3. This patch (of 3): The current calculation for splitting nodes tries to enforce a minimum span on the leaf nodes. This code is complex and never worked correctly to begin with, due to the min value being passed as 0 for all leaves. The calculation should just split the data as equally as possible between the new nodes. Note that b_end will be one more than the data, so the left side is still favoured in the calculation. The current code may also lead to a deficient node by not leaving enough data for the right side of the split. This issue is also addressed with the split calculation change. [Liam.Howlett@Oracle.com: rephrase the change log] Link: https://lkml.kernel.org/r/20241113031616.10530-1-richard.weiyang@gmail.com Link: https://lkml.kernel.org/r/20241113031616.10530-2-richard.weiyang@gmail.com Fixes: 54a611b60590 ("Maple Tree: add new data structure") Signed-off-by: Wei Yang Reviewed-by: Liam R. Howlett Cc: Sidhartha Kumar Cc: Lorenzo Stoakes Cc: Signed-off-by: Andrew Morton --- lib/maple_tree.c | 23 ++++++----------------- 1 file changed, 6 insertions(+), 17 deletions(-) --- a/lib/maple_tree.c~maple_tree-simplify-split-calculation +++ a/lib/maple_tree.c @@ -1863,11 +1863,11 @@ static inline int mab_no_null_split(stru * Return: The first split location. The middle split is set in @mid_split. */ static inline int mab_calc_split(struct ma_state *mas, - struct maple_big_node *bn, unsigned char *mid_split, unsigned long min) + struct maple_big_node *bn, unsigned char *mid_split) { unsigned char b_end = bn->b_end; int split = b_end / 2; /* Assume equal split. */ - unsigned char slot_min, slot_count = mt_slots[bn->type]; + unsigned char slot_count = mt_slots[bn->type]; /* * To support gap tracking, all NULL entries are kept together and a node cannot @@ -1900,18 +1900,7 @@ static inline int mab_calc_split(struct split = b_end / 3; *mid_split = split * 2; } else { - slot_min = mt_min_slots[bn->type]; - *mid_split = 0; - /* - * Avoid having a range less than the slot count unless it - * causes one node to be deficient. - * NOTE: mt_min_slots is 1 based, b_end and split are zero. - */ - while ((split < slot_count - 1) && - ((bn->pivot[split] - min) < slot_count - 1) && - (b_end - split > slot_min)) - split++; } /* Avoid ending a node on a NULL entry */ @@ -2377,7 +2366,7 @@ static inline struct maple_enode static inline unsigned char mas_mab_to_node(struct ma_state *mas, struct maple_big_node *b_node, struct maple_enode **left, struct maple_enode **right, struct maple_enode **middle, - unsigned char *mid_split, unsigned long min) + unsigned char *mid_split) { unsigned char split = 0; unsigned char slot_count = mt_slots[b_node->type]; @@ -2390,7 +2379,7 @@ static inline unsigned char mas_mab_to_n if (b_node->b_end < slot_count) { split = b_node->b_end; } else { - split = mab_calc_split(mas, b_node, mid_split, min); + split = mab_calc_split(mas, b_node, mid_split); *right = mas_new_ma_node(mas, b_node); } @@ -2877,7 +2866,7 @@ static void mas_spanning_rebalance(struc mast->bn->b_end--; mast->bn->type = mte_node_type(mast->orig_l->node); split = mas_mab_to_node(mas, mast->bn, &left, &right, &middle, - &mid_split, mast->orig_l->min); + &mid_split); mast_set_split_parents(mast, left, middle, right, split, mid_split); mast_cp_to_nodes(mast, left, middle, right, split, mid_split); @@ -3365,7 +3354,7 @@ static void mas_split(struct ma_state *m if (mas_push_data(mas, height, &mast, false)) break; - split = mab_calc_split(mas, b_node, &mid_split, prev_l_mas.min); + split = mab_calc_split(mas, b_node, &mid_split); mast_split_data(&mast, mas, split); /* * Usually correct, mab_mas_cp in the above call overwrites _ Patches currently in -mm which might be from richard.weiyang@gmail.com are