From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Upton Date: Fri, 31 May 2024 00:02:56 -0700 Subject: [PATCH v4 2/7] mm: multi-gen LRU: Have secondary MMUs participate in aging In-Reply-To: References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-3-jthoughton@google.com> Message-ID: List-Id: To: kvm-riscv@lists.infradead.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote: [...] > All optimizations in v2 were measured step by step. Even that bitmap, > which might be considered overengineered, brought a readily > measuarable 4% improvement in memcached throughput on Altra Max > swapping to Optane: That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this. Even if we were to take the series as-is, the door is wide open to subsequent improvements. > What I don't think is acceptable is simplifying those optimizations > out without documenting your justifications (I would even call it a > design change, rather than simplification, from v3 to v4). No, sorry, there's nothing wrong with James' approach here. The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4. You seriously cannot fault a contributor for respinning their work based on the provided feedback. -- Thanks, Oliver From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) (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 1FA4B80BF2 for ; Fri, 31 May 2024 07:03:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717138994; cv=none; b=Pti5Vc12d/M+c7x697AKCq8JfPot7CwGsBvNp6/48H0iJIlUzXNfewOJmpGRGhdOsvk0hxsBNAkT2F048GPRJEE8E9K1t5XVIuJ4HudAcIAvD+qGgO5HRaBVfl1Ge+S8Wz4m3F8zWosrPvRaRj6zcEeMWxlZ5CFDq0cy7hFquZI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717138994; c=relaxed/simple; bh=ci4Dj9A4R7c3SOWLTD2vJUP3/jPFngRAnm03r3E1GYQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Jta8ZffWVG5T5gqDUMWdON2kaMn047cXWMIeWY+/fHMNUjVY+vZJ+ei8ynqtrBzT/8dPSgi1kK5YrZtxaNeuVPojhpVXOVj1DfbL7yT8efPjLK1gp6C8mRzqjlYuVCif4w2dcakYSonSGzlUynVU+aVPfZwutk8BBx2paVOtb8Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=o0DHBTng; arc=none smtp.client-ip=95.215.58.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="o0DHBTng" X-Envelope-To: yuzhao@google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717138989; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=d2FOFsODXea2tbyL8aZD5XgmjgnWiDeEr9B1wNurnWA=; b=o0DHBTng4ZOfOuLPBmuUfGnVx3C/mCiuligouG4hr+A2usMgep5pVaKau5drtUXhfEyIMO t3GiWpR9A6MCmp5eyKFnNs5t3R9y4lyGtWM/ea5I3xB4nMIOdla7XklCl1bqpY8yR0z7s8 SKfEnl7I0/BFWAoSHps846Lw14bj3Fs= X-Envelope-To: jthoughton@google.com X-Envelope-To: seanjc@google.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: pbonzini@redhat.com X-Envelope-To: aou@eecs.berkeley.edu X-Envelope-To: ankita@nvidia.com X-Envelope-To: anup@brainfault.org X-Envelope-To: atishp@atishpatra.org X-Envelope-To: axelrasmussen@google.com X-Envelope-To: maobibo@loongson.cn X-Envelope-To: catalin.marinas@arm.com X-Envelope-To: dmatlack@google.com X-Envelope-To: rientjes@google.com X-Envelope-To: chenhuacai@kernel.org X-Envelope-To: james.morse@arm.com X-Envelope-To: corbet@lwn.net X-Envelope-To: maz@kernel.org X-Envelope-To: mpe@ellerman.id.au X-Envelope-To: npiggin@gmail.com X-Envelope-To: palmer@dabbelt.com X-Envelope-To: paul.walmsley@sifive.com X-Envelope-To: rananta@google.com X-Envelope-To: ryan.roberts@arm.com X-Envelope-To: shahuang@redhat.com X-Envelope-To: shuah@kernel.org X-Envelope-To: suzuki.poulose@arm.com X-Envelope-To: zhaotianrui@loongson.cn X-Envelope-To: will@kernel.org X-Envelope-To: yuzenghui@huawei.com X-Envelope-To: kvm-riscv@lists.infradead.org X-Envelope-To: kvm@vger.kernel.org X-Envelope-To: kvmarm@lists.linux.dev X-Envelope-To: linux-arm-kernel@lists.infradead.org X-Envelope-To: linux-doc@vger.kernel.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: linux-kselftest@vger.kernel.org X-Envelope-To: linux-mips@vger.kernel.org X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-riscv@lists.infradead.org X-Envelope-To: linuxppc-dev@lists.ozlabs.org X-Envelope-To: loongarch@lists.linux.dev Date: Fri, 31 May 2024 00:02:56 -0700 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Yu Zhao Cc: James Houghton , Sean Christopherson , Andrew Morton , Paolo Bonzini , Albert Ou , Ankit Agrawal , Anup Patel , Atish Patra , Axel Rasmussen , Bibo Mao , Catalin Marinas , David Matlack , David Rientjes , Huacai Chen , James Morse , Jonathan Corbet , Marc Zyngier , Michael Ellerman , Nicholas Piggin , Palmer Dabbelt , Paul Walmsley , Raghavendra Rao Ananta , Ryan Roberts , Shaoqin Huang , Shuah Khan , Suzuki K Poulose , Tianrui Zhao , Will Deacon , Zenghui Yu , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev Subject: Re: [PATCH v4 2/7] mm: multi-gen LRU: Have secondary MMUs participate in aging Message-ID: References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-3-jthoughton@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote: [...] > All optimizations in v2 were measured step by step. Even that bitmap, > which might be considered overengineered, brought a readily > measuarable 4% improvement in memcached throughput on Altra Max > swapping to Optane: That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this. Even if we were to take the series as-is, the door is wide open to subsequent improvements. > What I don't think is acceptable is simplifying those optimizations > out without documenting your justifications (I would even call it a > design change, rather than simplification, from v3 to v4). No, sorry, there's nothing wrong with James' approach here. The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4. You seriously cannot fault a contributor for respinning their work based on the provided feedback. -- Thanks, Oliver From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 307CEC27C44 for ; Fri, 31 May 2024 07:03:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=u59XheCL4+0coop8WQrQnrqh8UDsUT4x8e5/nHPgIV8=; b=xOvDOJbiqvU6yJ U5vCmdPJ2Qa0gxKmycmkujUpJYAW7zT6po85WKzVnJtEAP0qYstvGXQyN6WAKr0dlCbpo1uyL2mVm jMxSC+EGAG/LKnr7IFcPx9D35y1/kILNPzg6rcH3sbuIffkBjb+NjBi6PaBpLqIf7f/jnpStuG62d 7M+i4Pg4urpJsxm6Ap6l1VO2KuSVKMKMMWAsGCtFpJwKFrFCFtsZAMDlGSxqN0GC3e34c6FA/ygAV pKIGnvgrdg/tIqGGvPNnJCvCPz1l/hFSiBrmcDurBjbBIMhndggqca9oPDtAZLauByPZ92euia4dr v5UxjUweY11pzGNNxx1A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCwIJ-00000009SPn-0Rf3; Fri, 31 May 2024 07:03:19 +0000 Received: from out-173.mta1.migadu.com ([2001:41d0:203:375::ad]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCwIE-00000009SLx-1YfE; Fri, 31 May 2024 07:03:16 +0000 X-Envelope-To: yuzhao@google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717138989; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=d2FOFsODXea2tbyL8aZD5XgmjgnWiDeEr9B1wNurnWA=; b=o0DHBTng4ZOfOuLPBmuUfGnVx3C/mCiuligouG4hr+A2usMgep5pVaKau5drtUXhfEyIMO t3GiWpR9A6MCmp5eyKFnNs5t3R9y4lyGtWM/ea5I3xB4nMIOdla7XklCl1bqpY8yR0z7s8 SKfEnl7I0/BFWAoSHps846Lw14bj3Fs= X-Envelope-To: jthoughton@google.com X-Envelope-To: seanjc@google.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: pbonzini@redhat.com X-Envelope-To: aou@eecs.berkeley.edu X-Envelope-To: ankita@nvidia.com X-Envelope-To: anup@brainfault.org X-Envelope-To: atishp@atishpatra.org X-Envelope-To: axelrasmussen@google.com X-Envelope-To: maobibo@loongson.cn X-Envelope-To: catalin.marinas@arm.com X-Envelope-To: dmatlack@google.com X-Envelope-To: rientjes@google.com X-Envelope-To: chenhuacai@kernel.org X-Envelope-To: james.morse@arm.com X-Envelope-To: corbet@lwn.net X-Envelope-To: maz@kernel.org X-Envelope-To: mpe@ellerman.id.au X-Envelope-To: npiggin@gmail.com X-Envelope-To: palmer@dabbelt.com X-Envelope-To: paul.walmsley@sifive.com X-Envelope-To: rananta@google.com X-Envelope-To: ryan.roberts@arm.com X-Envelope-To: shahuang@redhat.com X-Envelope-To: shuah@kernel.org X-Envelope-To: suzuki.poulose@arm.com X-Envelope-To: zhaotianrui@loongson.cn X-Envelope-To: will@kernel.org X-Envelope-To: yuzenghui@huawei.com X-Envelope-To: kvm-riscv@lists.infradead.org X-Envelope-To: kvm@vger.kernel.org X-Envelope-To: kvmarm@lists.linux.dev X-Envelope-To: linux-arm-kernel@lists.infradead.org X-Envelope-To: linux-doc@vger.kernel.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: linux-kselftest@vger.kernel.org X-Envelope-To: linux-mips@vger.kernel.org X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-riscv@lists.infradead.org X-Envelope-To: linuxppc-dev@lists.ozlabs.org X-Envelope-To: loongarch@lists.linux.dev Date: Fri, 31 May 2024 00:02:56 -0700 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Yu Zhao Cc: James Houghton , Sean Christopherson , Andrew Morton , Paolo Bonzini , Albert Ou , Ankit Agrawal , Anup Patel , Atish Patra , Axel Rasmussen , Bibo Mao , Catalin Marinas , David Matlack , David Rientjes , Huacai Chen , James Morse , Jonathan Corbet , Marc Zyngier , Michael Ellerman , Nicholas Piggin , Palmer Dabbelt , Paul Walmsley , Raghavendra Rao Ananta , Ryan Roberts , Shaoqin Huang , Shuah Khan , Suzuki K Poulose , Tianrui Zhao , Will Deacon , Zenghui Yu , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev Subject: Re: [PATCH v4 2/7] mm: multi-gen LRU: Have secondary MMUs participate in aging Message-ID: References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-3-jthoughton@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240531_000314_940724_68835893 X-CRM114-Status: GOOD ( 10.53 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote: [...] > All optimizations in v2 were measured step by step. Even that bitmap, > which might be considered overengineered, brought a readily > measuarable 4% improvement in memcached throughput on Altra Max > swapping to Optane: That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this. Even if we were to take the series as-is, the door is wide open to subsequent improvements. > What I don't think is acceptable is simplifying those optimizations > out without documenting your justifications (I would even call it a > design change, rather than simplification, from v3 to v4). No, sorry, there's nothing wrong with James' approach here. The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4. You seriously cannot fault a contributor for respinning their work based on the provided feedback. -- Thanks, Oliver _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F3D3AC25B75 for ; Fri, 31 May 2024 07:04:36 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=o0DHBTng; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4VrDdH1XMbz30VT for ; Fri, 31 May 2024 17:04:35 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=o0DHBTng; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=linux.dev (client-ip=95.215.58.177; helo=out-177.mta1.migadu.com; envelope-from=oliver.upton@linux.dev; receiver=lists.ozlabs.org) Received: from out-177.mta1.migadu.com (out-177.mta1.migadu.com [95.215.58.177]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4VrDcM4tzXz30Tk for ; Fri, 31 May 2024 17:03:47 +1000 (AEST) X-Envelope-To: yuzhao@google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717138989; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=d2FOFsODXea2tbyL8aZD5XgmjgnWiDeEr9B1wNurnWA=; b=o0DHBTng4ZOfOuLPBmuUfGnVx3C/mCiuligouG4hr+A2usMgep5pVaKau5drtUXhfEyIMO t3GiWpR9A6MCmp5eyKFnNs5t3R9y4lyGtWM/ea5I3xB4nMIOdla7XklCl1bqpY8yR0z7s8 SKfEnl7I0/BFWAoSHps846Lw14bj3Fs= X-Envelope-To: jthoughton@google.com X-Envelope-To: seanjc@google.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: pbonzini@redhat.com X-Envelope-To: aou@eecs.berkeley.edu X-Envelope-To: ankita@nvidia.com X-Envelope-To: anup@brainfault.org X-Envelope-To: atishp@atishpatra.org X-Envelope-To: axelrasmussen@google.com X-Envelope-To: maobibo@loongson.cn X-Envelope-To: catalin.marinas@arm.com X-Envelope-To: dmatlack@google.com X-Envelope-To: rientjes@google.com X-Envelope-To: chenhuacai@kernel.org X-Envelope-To: james.morse@arm.com X-Envelope-To: corbet@lwn.net X-Envelope-To: maz@kernel.org X-Envelope-To: mpe@ellerman.id.au X-Envelope-To: npiggin@gmail.com X-Envelope-To: palmer@dabbelt.com X-Envelope-To: paul.walmsley@sifive.com X-Envelope-To: rananta@google.com X-Envelope-To: ryan.roberts@arm.com X-Envelope-To: shahuang@redhat.com X-Envelope-To: shuah@kernel.org X-Envelope-To: suzuki.poulose@arm.com X-Envelope-To: zhaotianrui@loongson.cn X-Envelope-To: will@kernel.org X-Envelope-To: yuzenghui@huawei.com X-Envelope-To: kvm-riscv@lists.infradead.org X-Envelope-To: kvm@vger.kernel.org X-Envelope-To: kvmarm@lists.linux.dev X-Envelope-To: linux-arm-kernel@lists.infradead.org X-Envelope-To: linux-doc@vger.kernel.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: linux-kselftest@vger.kernel.org X-Envelope-To: linux-mips@vger.kernel.org X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-riscv@lists.infradead.org X-Envelope-To: linuxppc-dev@lists.ozlabs.org X-Envelope-To: loongarch@lists.linux.dev Date: Fri, 31 May 2024 00:02:56 -0700 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Yu Zhao Subject: Re: [PATCH v4 2/7] mm: multi-gen LRU: Have secondary MMUs participate in aging Message-ID: References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-3-jthoughton@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: James Houghton , kvm@vger.kernel.org, linux-doc@vger.kernel.org, Catalin Marinas , Anup Patel , Paul Walmsley , linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-kselftest@vger.kernel.org, Raghavendra Rao Ananta , linux-riscv@lists.infradead.org, Shuah Khan , Jonathan Corbet , Marc Zyngier , Huacai Chen , David Rientjes , Zenghui Yu , Axel Rasmussen , linux-mips@vger.kernel.org, Albert Ou , Ryan Roberts , Will Deacon , Suzuki K Poulose , Shaoqin Huang , Nicholas Piggin , Bibo Mao , loongarch@lists.linux.dev, Atish Patra , David Matlack , Palmer Dabbelt , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Sean Christopherson , Ankit Agrawal , James Morse , kvm-riscv@lists.infradead.org, Paolo Bonzini , Andrew Morton , Tianrui Zhao , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote: [...] > All optimizations in v2 were measured step by step. Even that bitmap, > which might be considered overengineered, brought a readily > measuarable 4% improvement in memcached throughput on Altra Max > swapping to Optane: That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this. Even if we were to take the series as-is, the door is wide open to subsequent improvements. > What I don't think is acceptable is simplifying those optimizations > out without documenting your justifications (I would even call it a > design change, rather than simplification, from v3 to v4). No, sorry, there's nothing wrong with James' approach here. The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4. You seriously cannot fault a contributor for respinning their work based on the provided feedback. -- Thanks, Oliver From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 69CA6C25B75 for ; Fri, 31 May 2024 07:03:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=HsOdGaNsxzSeJ4718zYhpb0eL3idKHHOWPftnevlXHM=; b=nCbH/vU3DzIrQi h+iAhkK9VD4P6HTuvPBlFJuv2p4v/i+e3VcSkROHNIkCdKbOuw1PAgMvX8Y1mw5+Wo8LfA3w6Uem9 pdGSSQRvDhmKDxPyZXWAykwhKWxDVA3i4p3FLStYTuMG8ePddm1YpciTkyIAsIIojGTsUzeqaUzrX cH2fser1N9tiaE2RQ8NpDktovxG/O8bRq/LnYwLtEhbWMc+iMD8IK29cYHzT55yp1P13J6yskY+wN toltatg+pkCkyIL96FJvnBd/waaJBIwuNNFhuZlMTPABC/+2vjbljHxuFrVSNT/HnFzuu1F9UMBhq OjGAbk8Cw/j0h1vIV2IQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCwIH-00000009SOg-32hk; Fri, 31 May 2024 07:03:17 +0000 Received: from out-172.mta1.migadu.com ([2001:41d0:203:375::ac]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sCwIE-00000009SLq-1XuJ for linux-arm-kernel@lists.infradead.org; Fri, 31 May 2024 07:03:16 +0000 X-Envelope-To: yuzhao@google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717138989; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=d2FOFsODXea2tbyL8aZD5XgmjgnWiDeEr9B1wNurnWA=; b=o0DHBTng4ZOfOuLPBmuUfGnVx3C/mCiuligouG4hr+A2usMgep5pVaKau5drtUXhfEyIMO t3GiWpR9A6MCmp5eyKFnNs5t3R9y4lyGtWM/ea5I3xB4nMIOdla7XklCl1bqpY8yR0z7s8 SKfEnl7I0/BFWAoSHps846Lw14bj3Fs= X-Envelope-To: jthoughton@google.com X-Envelope-To: seanjc@google.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: pbonzini@redhat.com X-Envelope-To: aou@eecs.berkeley.edu X-Envelope-To: ankita@nvidia.com X-Envelope-To: anup@brainfault.org X-Envelope-To: atishp@atishpatra.org X-Envelope-To: axelrasmussen@google.com X-Envelope-To: maobibo@loongson.cn X-Envelope-To: catalin.marinas@arm.com X-Envelope-To: dmatlack@google.com X-Envelope-To: rientjes@google.com X-Envelope-To: chenhuacai@kernel.org X-Envelope-To: james.morse@arm.com X-Envelope-To: corbet@lwn.net X-Envelope-To: maz@kernel.org X-Envelope-To: mpe@ellerman.id.au X-Envelope-To: npiggin@gmail.com X-Envelope-To: palmer@dabbelt.com X-Envelope-To: paul.walmsley@sifive.com X-Envelope-To: rananta@google.com X-Envelope-To: ryan.roberts@arm.com X-Envelope-To: shahuang@redhat.com X-Envelope-To: shuah@kernel.org X-Envelope-To: suzuki.poulose@arm.com X-Envelope-To: zhaotianrui@loongson.cn X-Envelope-To: will@kernel.org X-Envelope-To: yuzenghui@huawei.com X-Envelope-To: kvm-riscv@lists.infradead.org X-Envelope-To: kvm@vger.kernel.org X-Envelope-To: kvmarm@lists.linux.dev X-Envelope-To: linux-arm-kernel@lists.infradead.org X-Envelope-To: linux-doc@vger.kernel.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: linux-kselftest@vger.kernel.org X-Envelope-To: linux-mips@vger.kernel.org X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-riscv@lists.infradead.org X-Envelope-To: linuxppc-dev@lists.ozlabs.org X-Envelope-To: loongarch@lists.linux.dev Date: Fri, 31 May 2024 00:02:56 -0700 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Oliver Upton To: Yu Zhao Cc: James Houghton , Sean Christopherson , Andrew Morton , Paolo Bonzini , Albert Ou , Ankit Agrawal , Anup Patel , Atish Patra , Axel Rasmussen , Bibo Mao , Catalin Marinas , David Matlack , David Rientjes , Huacai Chen , James Morse , Jonathan Corbet , Marc Zyngier , Michael Ellerman , Nicholas Piggin , Palmer Dabbelt , Paul Walmsley , Raghavendra Rao Ananta , Ryan Roberts , Shaoqin Huang , Shuah Khan , Suzuki K Poulose , Tianrui Zhao , Will Deacon , Zenghui Yu , kvm-riscv@lists.infradead.org, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev Subject: Re: [PATCH v4 2/7] mm: multi-gen LRU: Have secondary MMUs participate in aging Message-ID: References: <20240529180510.2295118-1-jthoughton@google.com> <20240529180510.2295118-3-jthoughton@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240531_000314_933552_FF379CE1 X-CRM114-Status: GOOD ( 11.21 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, May 31, 2024 at 12:05:48AM -0600, Yu Zhao wrote: [...] > All optimizations in v2 were measured step by step. Even that bitmap, > which might be considered overengineered, brought a readily > measuarable 4% improvement in memcached throughput on Altra Max > swapping to Optane: That's great, but taking an iterative approach to the problem allows the reviewers and maintainers to come to their own conclusions about each optimization independently. Squashing all of that together and posting the result doesn't allow for this. Even if we were to take the series as-is, the door is wide open to subsequent improvements. > What I don't think is acceptable is simplifying those optimizations > out without documenting your justifications (I would even call it a > design change, rather than simplification, from v3 to v4). No, sorry, there's nothing wrong with James' approach here. The discussion that led to the design of v4 happened on list; you were on CC. The general consensus on the KVM side was that the bitmap was complicated and lacked independent justification. There was ample opportunity to voice your concerns before he spent the time on v4. You seriously cannot fault a contributor for respinning their work based on the provided feedback. -- Thanks, Oliver _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel