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On Saturday, 2 May 2020 10:54:02 BST Dale wrote: |
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> Michael wrote: |
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> > I'd be interested to know as a comparison if Nikos' and Dale's I/O |
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> > unresponsiveness in swapping sees an improvement with the I/O scheduler |
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> > for |
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> > spinning drives set to bfq; e.g.: |
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> > |
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> > echo bfq > /sys/block/sda/queue/scheduler |
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> |
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> This is its setting at the moment. |
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> |
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> |
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> root@fireball / # cat /sys/block/sda/queue/scheduler |
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> noop deadline [cfq] |
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> root@fireball / # |
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Ahh, you must be on an older kernel? |
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I'm on 5.4.28 here and these are the new kernel scheduler options: |
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# |
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# IO Schedulers |
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# |
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CONFIG_MQ_IOSCHED_DEADLINE=y |
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CONFIG_MQ_IOSCHED_KYBER=y |
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CONFIG_IOSCHED_BFQ=y |
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CONFIG_BFQ_GROUP_IOSCHED=y |
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# CONFIG_BFQ_CGROUP_DEBUG is not set |
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# end of IO Schedulers |
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The BFQ scheduler has a number of tunable parameters via sysctl, like weight, |
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latency and what not, but unless you're into running endless benchmark tests |
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to tune your particular devices, I'd leave it to do its thing with default |
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settings. |
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> I know I can echo it in but where do I set that to that when booting? |
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You can set a local script to switch from other schedulers - the default is |
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mq-deadline - or you can disable the others in the kernel. I don't know if |
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you can pass an option to the kernel line at boot time. |
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I understand this is more effective with slow(er) spinning drives and perhaps |
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old SSDs. NVMe drives won't benefit from it and are better run with the |
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default mq-deadline scheduler. |
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