blk-throttle: force user to configure all settings for io.low
authorShaohua Li <shli@fb.com>
Wed, 17 May 2017 20:07:27 +0000 (13:07 -0700)
committerJens Axboe <axboe@fb.com>
Mon, 22 May 2017 20:47:12 +0000 (14:47 -0600)
commitb4f428ef2844e9fa8154f2faaca249aa74e222a7
treee9e7bc1bc5ca0ec95caac8e6d4bd909afe5f3b1c
parent9bb67aeb96784527dbc784c7a1b234461299363c
blk-throttle: force user to configure all settings for io.low

Default value of io.low limit is 0. If user doesn't configure the limit,
last patch makes cgroup be throttled to very tiny bps/iops, which could
stall the system. A cgroup with default settings of io.low limit really
means nothing, so we force user to configure all settings, otherwise
io.low limit doesn't take effect. With this stragety, default setting of
latency/idle isn't important, so just set them to very conservative and
safe value.

Signed-off-by: Shaohua Li <shli@fb.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
block/blk-throttle.c