From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 8E35F2D8DBB for ; Mon, 25 May 2026 18:58:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779735489; cv=none; b=SS8wUG8qfKVbrg63SePMET1n+U1jmo/6jb6SdysTf7UUo97ObIo2sQY++VW4rPruNKGCkKeplsPSNBQxr95z6rFDkoHQadaFIFLAa/NELUm9IIGbrkChDYtJx+UNQq+6yYd/VQ28pZcpq2lm6EUVKcx4qhiINqSwXzp19l4zH2Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779735489; c=relaxed/simple; bh=zyUvlsDc6AqgLAI3fp7ONRPIZRslDLIiZ7HyGKjglfQ=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=uYJnLeFvESirzud0Fp4Um2Plmr9DPa+9o+OhqD3OTUJsCQ0IgcPfn/P9pWcNHb4jo5TDdYmcmGwP8iWeGgJiu9xc6oKyDzZjX+lJkjTcreIeZS2K6zxgu1NMyNufyJMIE2a4wmQ2XqWnnIXiuDiVcB7avIfBDF9Y7zkiRyliO7w= 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=u2w2gr0Y; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="u2w2gr0Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 892C61F000E9; Mon, 25 May 2026 18:58:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1779735488; bh=5h0W9zXzP3LFNcoEiplpRZRXlPDTTCik1KUxrC76J+k=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=u2w2gr0YGcHnt9X/m+yRa0iAOu2xjQP3QaGLS7+kOpjoQt9aXLflVESz1avgMeY8O J40y+Hdlu1CbOIxP6Z/l03uL9wDAdSkpoJqsjGZCbpmRowzpfnPrKCbuFW+oMpOIvE 9Wj2D6Ko6aBx2M2RceQuFaqxq2m6eunySfPYjU/g= Date: Mon, 25 May 2026 11:58:07 -0700 From: Andrew Morton To: Zhang Peng Cc: David Hildenbrand , Lorenzo Stoakes , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Johannes Weiner , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Michal Hocko , "Liam R. Howlett" , Qi Zheng , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Barry Song , Kairui Song , Zhang Peng Subject: Re: [PATCH v4 0/5] mm: batch TLB flushing for dirty folios in vmscan Message-Id: <20260525115807.9655b788356bde7a9899f9f5@linux-foundation.org> In-Reply-To: <20260525-batch-tlb-flush-v4-0-83789d6abc00@icloud.com> References: <20260525-batch-tlb-flush-v4-0-83789d6abc00@icloud.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 25 May 2026 22:57:16 +0800 Zhang Peng wrote: > This series introduces batch TLB flushing optimization for dirty folios > during memory reclaim, aiming to reduce IPI overhead on multi-core systems. So often we see such good results from batching things. > ... > > Testing > ------- > The benchmark script uses stress-ng to compare TLB shootdown behavior before and > after this patch. It constrains a stress-ng workload via memcg to force reclaim > through shrink_folio_list(), reporting TLB shootdowns and IPIs. > > Core benchmark command: stress-ng --vm 16 --vm-bytes 2G --vm-keep --timeout 60 > > ========================================================================== > batch_dirty_tlb_flush Benchmark Results > ========================================================================== > Kernel: 7.0.0-rc1+ CPUs: 16 > MemTotal: 31834M SwapTotal: 8191M > memcg limit: 512M alloc: 2G workers: 16 duration: 60s > -------------------------------------------------------------------------- > Metric Before After Delta (abs / %) > -------------------------------------------------------------------------- > bogo ops/s 28238.63 35833.97 +7595.34 (+26.9%) > TLB shootdowns 55428953 17621697 -37807256 (-68.2%) > Function call IPIs 34073695 14498768 -19574927 (-57.4%) > pgscan_anon (pages) 52856224 60252894 7396670 (+14.0%) > pgsteal_anon (pages) 29004962 34054753 5049791 (+17.4%) > -------------------------------------------------------------------------- Nice. AI review asked a few things: https://sashiko.dev/#/patchset/20260525-batch-tlb-flush-v4-0-83789d6abc00@icloud.com Thanks. I'll take no action at this time - there's no review yet and we're at -rc5.