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Mon, 5 Jul 2021 16:23:28 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 3CC481F2C5D; Mon, 5 Jul 2021 18:23:28 +0200 (CEST) From: Jan Kara To: Andrew Morton Cc: , Michael Stapelberg , , Jan Kara Subject: [PATCH 0/5] writeback: Fix bandwidth estimates Date: Mon, 5 Jul 2021 18:23:14 +0200 Message-Id: <20210705161610.19406-1-jack@suse.cz> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=623; h=from:subject:message-id; bh=DqLhdy4UPcOF1ZuX1969TFdVBviX62+G4LL+t/kjhxU=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBg4zHIs/3N3oE1F3qFYcDXab0TKVkwzWuzYHfZ7bvT UdoQ4dGJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCYOMxyAAKCRCcnaoHP2RA2T1rB/ 9v1ifEYYcMbpKOVyD5aqLbjHQsGO7w5i/Mx3x9I87shL3uy0Abj7wUbl5XqAqZLvzt+ajNI2H4cqYu SChz9DJuIjB/Bu/nI+27QSLHiYzGJS4BdPDV6xng/cSHaIBwuQACSu7IeIuP5LhxjtFNDNGYk7qbuX 1xtT0AfFGdvLW7rB07y+Y+Fxp8tr8MuxzP35LWe6+HXYk2uTqPvyFS2dpW9klY8RkGkLUQf+HrJqxs SMv8tk85amTpA3yXXIo4Si1upPvejJT4R06XoH6XMA651+3MhoWmV4YgSlbuit12EzKVjy2zZ1VPAr RcqMxN/Tp+MLwNlSjHc3H6DTgzTtwi X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=suse.cz header.s=susede2_rsa header.b=rZInqvnl; dkim=pass header.d=suse.cz header.s=susede2_ed25519 header.b="o6DGDK/M"; spf=pass (imf01.hostedemail.com: domain of jack@suse.cz designates 195.135.220.29 as permitted sender) smtp.mailfrom=jack@suse.cz; dmarc=none X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 83CB65003B40 X-Stat-Signature: sb389xd3dwa54u19gx5jrtw6shu6io3h X-HE-Tag: 1625502211-839931 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: Hello, this patch series fixes estimate of writeback throughput when device is not fully busy doing writeback. Michael Stapelberg has reported that such workload (e.g. generated by linking) tends to push estimated throughput down to 0 and as a result writeback on the device is practically stalled. The first three patches fix the reported issue, the remaining two patches are unrelated cleanups of problems I've noticed when reading the code. Michael, can you try whether these patches fix the problems you've observed? I cannot trigger the "bandwidth going down" spiral with them anymore. Honza