From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id B7C57371867; Tue, 24 Mar 2026 13:35:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774359352; cv=none; b=QbyFuenCR65LlZpkuN7Y0rhXX+J+b0IGzbZ0KJNnBrITceMtqHB+Caatx00vqtx+En0BFpTnb9I61R1b+RX/eh/E39OSyq534o6lCjm1Ai+QNW/himJjSEGQRY+R6RUaJZKHJTm/F71qcSz8zbYIIixK8/Es7tKzO4nUW5h2YVg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774359352; c=relaxed/simple; bh=vl2OXl2LVtwWCfThahPA38qmIKBgDZZ2FO5uliPOXaQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=HeQuvUhqdfFCipWtHT9DBVYRB4WOGanM9K4TMSHoeFqzWjdPw7+GFziA+W/+oPyBnrn1GfVF5DK8Fqw7F+b1iJdfiL2+Gb99LCytCgj8Is1ycDzmVDUesIG5VRK2UBVpy6SdRXWNPF28YTQM4kFxzZBlPVjGozol8fveSMXIuQM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=YrOiJ1S4; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="YrOiJ1S4" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 267011476; Tue, 24 Mar 2026 06:35:44 -0700 (PDT) Received: from e142334-100.cambridge.arm.com (e142334-100.cambridge.arm.com [10.1.194.63]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B07DA3F836; Tue, 24 Mar 2026 06:35:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1774359350; bh=vl2OXl2LVtwWCfThahPA38qmIKBgDZZ2FO5uliPOXaQ=; h=From:To:Cc:Subject:Date:From; b=YrOiJ1S4OX/2cBG3iTjFDWXRB27gOHHkVQ98dP48Z3JlKlbtaQ1trhiRDRbf9SC24 y+TukdXunVA/89hdgTqOvGHZeKIkFVCCFHrZAHSgQH7+9ke1HLl6uOYJL/A6zfvmIt K4R9I7u2Qs06b/PHODVKGsSTHeB1S3ptLvBx9XgI= From: Muhammad Usama Anjum To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Uladzislau Rezki , Nick Terrell , David Sterba , Vishal Moola , linux-mm@kvack.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, Ryan.Roberts@arm.com, david.hildenbrand@arm.com Cc: Muhammad Usama Anjum Subject: [PATCH v3 0/3] mm: Free contiguous order-0 pages efficiently Date: Tue, 24 Mar 2026 13:35:31 +0000 Message-ID: <20260324133538.497616-1-usama.anjum@arm.com> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Hi All, A recent change to vmalloc caused some performance benchmark regressions (see [1]). I'm attempting to fix that (and at the same time significantly improve beyond the baseline) by freeing a contiguous set of order-0 pages as a batch. At the same time I observed that free_contig_range() was essentially doing the same thing as vfree() so I've fixed it there too. While at it, optimize the __free_contig_frozen_range() as well. [1] https://lore.kernel.org/all/66919a28-bc81-49c9-b68f-dd7c73395a0d@arm.com v6.18 - Before the patch causing regression was added mm-new - current latest code this series - v2 series of these patches (>0 is faster, <0 is slower, (R)/(I) = statistically significant Regression/Improvement) v6.18 vs mm-new +-----------------+----------------------------------------------------------+-------------------+-------------+ | Benchmark | Result Class | v6.18 (base) | mm-new | +=================+==========================================================+===================+=============+ | micromm/vmalloc | fix_align_alloc_test: p:1, h:0, l:500000 (usec) | 653643.33 | (R) -50.92% | | | fix_size_alloc_test: p:1, h:0, l:500000 (usec) | 366167.33 | (R) -11.96% | | | fix_size_alloc_test: p:4, h:0, l:500000 (usec) | 489484.00 | (R) -35.21% | | | fix_size_alloc_test: p:16, h:0, l:500000 (usec) | 1011250.33 | (R) -36.45% | | | fix_size_alloc_test: p:16, h:1, l:500000 (usec) | 1086812.33 | (R) -31.83% | | | fix_size_alloc_test: p:64, h:0, l:100000 (usec) | 657940.00 | (R) -38.62% | | | fix_size_alloc_test: p:64, h:1, l:100000 (usec) | 765422.00 | (R) -24.84% | | | fix_size_alloc_test: p:256, h:0, l:100000 (usec) | 2468585.00 | (R) -37.83% | | | fix_size_alloc_test: p:256, h:1, l:100000 (usec) | 2815758.33 | (R) -26.32% | | | fix_size_alloc_test: p:512, h:0, l:100000 (usec) | 4851969.00 | (R) -37.76% | | | fix_size_alloc_test: p:512, h:1, l:100000 (usec) | 4496257.33 | (R) -31.15% | | | full_fit_alloc_test: p:1, h:0, l:500000 (usec) | 570605.00 | -8.97% | | | kvfree_rcu_1_arg_vmalloc_test: p:1, h:0, l:500000 (usec) | 500866.00 | -5.88% | | | kvfree_rcu_2_arg_vmalloc_test: p:1, h:0, l:500000 (usec) | 499733.00 | -6.95% | | | long_busy_list_alloc_test: p:1, h:0, l:500000 (usec) | 5266237.67 | (R) -40.19% | | | pcpu_alloc_test: p:1, h:0, l:500000 (usec) | 490284.00 | -2.10% | | | random_size_align_alloc_test: p:1, h:0, l:500000 (usec) | 850986.33 | (R) -48.03% | | | random_size_alloc_test: p:1, h:0, l:500000 (usec) | 2712106.00 | (R) -40.48% | | | vm_map_ram_test: p:1, h:0, l:500000 (usec) | 111151.33 | 3.52% | +-----------------+----------------------------------------------------------+-------------------+-------------+ v6.18 vs mm-new with patches +-----------------+----------------------------------------------------------+-------------------+--------------+ | Benchmark | Result Class | v6.18 (base) | this series | +=================+==========================================================+===================+==============+ | micromm/vmalloc | fix_align_alloc_test: p:1, h:0, l:500000 (usec) | 653643.33 | -14.02% | | | fix_size_alloc_test: p:1, h:0, l:500000 (usec) | 366167.33 | -7.23% | | | fix_size_alloc_test: p:4, h:0, l:500000 (usec) | 489484.00 | -1.57% | | | fix_size_alloc_test: p:16, h:0, l:500000 (usec) | 1011250.33 | 1.57% | | | fix_size_alloc_test: p:16, h:1, l:500000 (usec) | 1086812.33 | (I) 15.75% | | | fix_size_alloc_test: p:64, h:0, l:100000 (usec) | 657940.00 | (I) 9.05% | | | fix_size_alloc_test: p:64, h:1, l:100000 (usec) | 765422.00 | (I) 38.45% | | | fix_size_alloc_test: p:256, h:0, l:100000 (usec) | 2468585.00 | (I) 12.56% | | | fix_size_alloc_test: p:256, h:1, l:100000 (usec) | 2815758.33 | (I) 38.61% | | | fix_size_alloc_test: p:512, h:0, l:100000 (usec) | 4851969.00 | (I) 13.43% | | | fix_size_alloc_test: p:512, h:1, l:100000 (usec) | 4496257.33 | (I) 49.21% | | | full_fit_alloc_test: p:1, h:0, l:500000 (usec) | 570605.00 | -8.47% | | | kvfree_rcu_1_arg_vmalloc_test: p:1, h:0, l:500000 (usec) | 500866.00 | -8.17% | | | kvfree_rcu_2_arg_vmalloc_test: p:1, h:0, l:500000 (usec) | 499733.00 | -5.54% | | | long_busy_list_alloc_test: p:1, h:0, l:500000 (usec) | 5266237.67 | (I) 4.63% | | | pcpu_alloc_test: p:1, h:0, l:500000 (usec) | 490284.00 | 1.53% | | | random_size_align_alloc_test: p:1, h:0, l:500000 (usec) | 850986.33 | -0.00% | | | random_size_alloc_test: p:1, h:0, l:500000 (usec) | 2712106.00 | 1.22% | | | vm_map_ram_test: p:1, h:0, l:500000 (usec) | 111151.33 | (I) 4.98% | +-----------------+----------------------------------------------------------+-------------------+--------------+ mm-new vs vmalloc_2 results are in 2/3 patch. So this series is mitigating the regression on average as results show -14% to 49% improvement. Thanks, Muhammad Usama Anjum --- Changes since v2: (summary) - Patch 1 and 3: Rework the loop to check for memory sections - Patch 2: Rework by removing the BUG on and add helper free_pages_bulk() Changes since v1: - Update description - Rebase on mm-new and rerun benchmarks/tests - Patch 1: move FPI_PREPARED check and add todo - Patch 2: Rework catering newer changes in vfree() - New Patch 3: optimizes __free_contig_frozen_range() Muhammad Usama Anjum (1): mm/page_alloc: Optimize __free_contig_frozen_range() Ryan Roberts (2): mm/page_alloc: Optimize free_contig_range() vmalloc: Optimize vfree include/linux/gfp.h | 4 ++ mm/page_alloc.c | 146 ++++++++++++++++++++++++++++++++++++++++++-- mm/vmalloc.c | 16 ++--- 3 files changed, 151 insertions(+), 15 deletions(-) -- 2.47.3