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 X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0686BC433E0 for ; Sat, 20 Mar 2021 16:33:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D599661967 for ; Sat, 20 Mar 2021 16:33:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229894AbhCTQc4 (ORCPT ); Sat, 20 Mar 2021 12:32:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:49542 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229761AbhCTQcv (ORCPT ); Sat, 20 Mar 2021 12:32:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9923961934; Sat, 20 Mar 2021 16:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1616257971; bh=WdUxKSETKcrjBZWfh67ufbdZG8tgIef5zeapBbsXIO4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=BvJy91r/xPJQ8TUhms4zJXAeQ4JjQyRMHpSH+J/t+PshlcnFIyfVVma+n4FauXHNK JJmU1xS8qmmRUXGq8D+66H/D1R3jsEy31C8bUhiu/FPYERlHAiszKng4AExesa6RV8 Q/rQPfRcAx6QWZzZT7sEWsp4GBQ+kGqJywmKe0B8= Date: Sat, 20 Mar 2021 09:32:49 -0700 From: Andrew Morton To: Minchan Kim Cc: linux-mm , LKML , joaodias@google.com, surenb@google.com, cgoldswo@codeaurora.org, willy@infradead.org, mhocko@suse.com, david@redhat.com, vbabka@suse.cz, linux-fsdevel@vger.kernel.org, oliver.sang@intel.com Subject: Re: [PATCH v4 3/3] mm: fs: Invalidate BH LRU during page migration Message-Id: <20210320093249.2df740cd139449312211c452@linux-foundation.org> In-Reply-To: <20210319175127.886124-3-minchan@kernel.org> References: <20210319175127.886124-1-minchan@kernel.org> <20210319175127.886124-3-minchan@kernel.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Mar 2021 10:51:27 -0700 Minchan Kim wrote: > Pages containing buffer_heads that are in one of the per-CPU > buffer_head LRU caches will be pinned and thus cannot be migrated. > This can prevent CMA allocations from succeeding, which are often used > on platforms with co-processors (such as a DSP) that can only use > physically contiguous memory. It can also prevent memory > hot-unplugging from succeeding, which involves migrating at least > MIN_MEMORY_BLOCK_SIZE bytes of memory, which ranges from 8 MiB to 1 > GiB based on the architecture in use. > > Correspondingly, invalidate the BH LRU caches before a migration > starts and stop any buffer_head from being cached in the LRU caches, > until migration has finished. > > Tested-by: Oliver Sang > Reported-by: kernel test robot > Signed-off-by: Chris Goldsworthy > Signed-off-by: Minchan Kim The signoff chain ordering might mean that Chris was the primary author, but there is no From:him. Please clarify?