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bh=1P2KNZzmPBQ/jvFABigQoqWTKQltEhWgYJBtKz3MZKI=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=xafP8tEBL+FHQKa8mDTMg+iZRLQPxVNwMhB0AgPseJ3hM7dFpvWNr3aVFZqSxAwAj TW9xlfyotihADUkqhTJXY3C8JqWmStXYLoObk5zEyUolPJq1iGqJkFfIKeMpNUIqK5 YheGwCwNBLu3KVwDPNbm6ITkDI47dhyEm/3ZMTQg= Date: Mon, 10 Apr 2023 21:36:18 -0700 From: Andrew Morton To: yizhou.tang@shopee.com Cc: neilb@suse.com, tj@kernel.org, wufengguang@huawei.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, tangyeechou@gmail.com, chunguang.xu@shopee.com, yue.zhao@shopee.com Subject: Re: [PATCH] mm: Fix memcg writeback for rt tasks Message-Id: <20230410213618.0d8b2b19a15376dfd49e3c53@linux-foundation.org> In-Reply-To: <20230403165708.352841-1-yizhou.tang@shopee.com> References: <20230403165708.352841-1-yizhou.tang@shopee.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: 1kyauahgdykie93ufxn6nodqx8pq7k8k X-Rspamd-Queue-Id: C011140003 X-HE-Tag: 1681187780-749565 X-HE-Meta: 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 gqtbhqHs OLlxqmByZuBBSuy+yriVEiITgPxuSjs8cX0qLU+hC2QqGlfcsu6O1/4G8iS/u6QgWSFI8qWYB4OPg/N6tKoOSuXijZ7nUW2kv8kGASlOrqZL7C8X8e2GdOxU29gylFc5P8YgHIxKs51POrUHMTbgUN3tcPd9R5qf2YjmR7Us00PaX8KrRmVn9Fxewh1Xcsx/V8vSQ10HMC+TofW8WfVszrKa1ff/0YDZz/ChM5r0tkFxCNjjYbuon+WYazKXSRrZ9s927cNqZ7fmrCDDZU/ofAibDZHxT/vG5hoUDr3Oz2RddiZG5aSninTd07q3k0rtQZhDQuVqC25+9zf/Pe/JRPp23tzRdXa7lZ3db8MC2oGHDsOvMSWgGcpjVbRYwwiScrbg9FWViUGDBHkrPu2g/Jh++UA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 4 Apr 2023 00:57:08 +0800 yizhou.tang@shopee.com wrote: > From: Tang Yizhou > > Neil said he didn't know what was wanted for realtime in the commit > message of commit a37b0715ddf3 ("mm/writeback: replace PF_LESS_THROTTLE > with PF_LOCAL_THROTTLE"). I think we need to distinguish between the > global writeback and memcg writeback in domain_dirty_limits() for the > rt tasks. Why do you think this? > Fixes: a53eaff8c119 ("MM: increase safety margin provided by PF_LESS_THROTTLE") In what way does it fix it? Please describe the user-visible effects of this change.