From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sun, 22 Mar 2020 02:51:16 +0300 From: "Dmitry V. Levin" To: ALT Devel discussion list Message-ID: <20200321235116.GA26284@altlinux.org> References: <1276556985.742599.1584648710620.JavaMail.zimbra@taf.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=koi8-r Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Subject: Re: [devel] =?koi8-r?b?8cTSwSA0LjE5LzUuNCDJIMTJ08vP19nKINvFxNXMxdI=?= X-BeenThere: devel@lists.altlinux.org X-Mailman-Version: 2.1.12 Precedence: list Reply-To: ALT Linux Team development discussions List-Id: ALT Linux Team development discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Mar 2020 23:51:16 -0000 Archived-At: List-Archive: List-Post: On Sun, Mar 22, 2020 at 02:32:01AM +0300, Mikhail Novosyolov wrote: > 19.03.2020 23:26, Leonid Krivoshein пишет: > > 19.03.2020 23:11, alexei@taf.ru пишет: > >> Добрый день! > >> > >> Скажите, кто знает, а вот такая картина на ядрах, начиная с 4.19, нормальная?: > >> > >> # cat /sys/block/sda/queue/scheduler > >> [none] bfq > >> > >> при том на 4.9 имеем такую картину: > >> > >> # cat /sys/block/sda/queue/scheduler > >> noop [deadline] > > > > А /dev/sda то какой? Для NVME и некоторых SSD вообще лучше noop. > > В шляпе и в хуавей решили, что лучше bfq: > > https://gitee.com/src-openeuler/systemd/blob/master/0001-udev-use-bfq-as-the-default-scheduler.patch Тут много познавательного написано на эту тему, почитайте: https://github.com/systemd/systemd/pull/13321 > А для каких "некоторых" SSD лучше noop и почему? "It is worth noting that there is little difference in throughput between the mq-deadline/none/bfq I/O schedulers when using fast multi-queue SSD configurations or fast NVME devices. In these cases it may be preferable to use the 'none' I/O scheduler to reduce CPU overhead." -- ldv