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 4E53FCCF9F8 for ; Thu, 6 Nov 2025 10:30:37 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4d2JP7537bz3bfQ; Thu, 6 Nov 2025 21:30:35 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1762425035; cv=none; b=RzREIgSRMdxAeAgJiz5MciFW5Bb+0HE6y1eI+yOT84bje7FZdSsyG9Iio0B7TfjSihLKiW39vGyhCGNzq2qSsylwPWRA7A+pKp268CF4Z+jbSHE+GppybuhU6y5uiao0yw2OmexcFFVge/XxRl9AbN2yPm+TfNMSFgWLr5fpbvCjmk8lmu8YjG6bJjookYrBKbmDXkX0GU355uD/OKgqFW/MyyMVUjHEGDq0RRWb2LDbcLM1Z/c4Q6Y2cFEize/kqSml9ZycfcHSdQlG2h7tGR+rM8dGZhtkqclq+1WkTTt3pzHDs8jFDR4nPfueCx7EOcgrykDxsPuT2iHHzbiCiA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1762425035; c=relaxed/relaxed; bh=kXPFrNUNPhhkMe5rhwtRP1Qi03luuYdSthxJanNeerc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=S64lpULFAXpCKQLPIYwaeoqMqcSwZ0Fp2wEsjM2vrJaK308e3j6KD3V/ZGSyl+SkBd6OjouEJNN4oy3LvOLhHiALwRu/MOfql+WehztM43lFv8/P4J4jDriOG446Q7zIO/+coyteTxGssSoVfVoeJh2H5Y0WAKF8HlmyMFBX0Dt4FoHIFd5P9gJyTlhLLDBFzwtz9ESdfQNQhPA69OBlAhGP7hOPUz7uf7iFHOnTlkxoHEisdRrqNBIpJnopwob+iQpebTPOO4QybsWVPjwijOxkywSUYmHjLDzH91vwILv3FqvUiQXGJ0HjLIHKHMLy9kIczO+O8PlKpB9hZ/Iykw== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=kevin.brodsky@arm.com; receiver=lists.ozlabs.org) smtp.mailfrom=arm.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=arm.com (client-ip=217.140.110.172; helo=foss.arm.com; envelope-from=kevin.brodsky@arm.com; receiver=lists.ozlabs.org) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lists.ozlabs.org (Postfix) with ESMTP id 4d2JP6544Yz2ySP for ; Thu, 6 Nov 2025 21:30:32 +1100 (AEDT) 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 B85731596; Thu, 6 Nov 2025 02:29:52 -0800 (PST) Received: from [10.1.34.75] (unknown [10.1.34.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CB9A53F66E; Thu, 6 Nov 2025 02:29:53 -0800 (PST) Message-ID: Date: Thu, 6 Nov 2025 10:29:50 +0000 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v4 01/12] powerpc/64s: Do not re-activate batched TLB flush To: "Ritesh Harjani (IBM)" , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Alexander Gordeev , Andreas Larsson , Andrew Morton , Boris Ostrovsky , Borislav Petkov , Catalin Marinas , Christophe Leroy , Dave Hansen , David Hildenbrand , "David S. Miller" , David Woodhouse , "H. Peter Anvin" , Ingo Molnar , Jann Horn , Juergen Gross , "Liam R. Howlett" , Lorenzo Stoakes , Madhavan Srinivasan , Michael Ellerman , Michal Hocko , Mike Rapoport , Nicholas Piggin , Peter Zijlstra , Ryan Roberts , Suren Baghdasaryan , Thomas Gleixner , Vlastimil Babka , Will Deacon , Yeoreum Yun , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, xen-devel@lists.xenproject.org, x86@kernel.org, Venkat Rao Bagalkote References: <20251029100909.3381140-1-kevin.brodsky@arm.com> <20251029100909.3381140-2-kevin.brodsky@arm.com> <87qzud42n1.ritesh.list@gmail.com> Content-Language: en-GB From: Kevin Brodsky In-Reply-To: <87qzud42n1.ritesh.list@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 05/11/2025 02:46, Ritesh Harjani (IBM) wrote: > Kevin Brodsky writes: > >> From: Alexander Gordeev >> >> Since commit b9ef323ea168 ("powerpc/64s: Disable preemption in hash >> lazy mmu mode") a task can not be preempted while in lazy MMU mode. >> Therefore, the batch re-activation code is never called, so remove it. >> >> Signed-off-by: Alexander Gordeev >> Signed-off-by: Kevin Brodsky >> --- >> arch/powerpc/include/asm/thread_info.h | 2 -- >> arch/powerpc/kernel/process.c | 25 ------------------------- >> 2 files changed, 27 deletions(-) >> > Since the commit referenced in above disables the preemption in > arch_enter_lazy_mmu(), so the expectation is that we will never be > context switched while in lazy_mmu, hence the code changes in > switch_to() around __flush_tlb_pending() should ideally never be called. Correct, that's the idea. > With this analysis - the patch looks good to me. I will give this entire > patch series a try on Power HW with Hash mmu too (which uses lazy mmu and > let you know the results of that)! That'd be very appreciated, thanks a lot! > For this patch please feel free to add: > Reviewed-by: Ritesh Harjani (IBM) > > > CC: Venkat who also runs CI on linux Power HW for upstream testing :) Ack, will Cc you both in the next version. - Kevin