Messages in this thread | | | From | Ming Lei <> | Date | Wed, 6 Jul 2016 23:39:29 +0800 | Subject | Re: Re: cgroup: Fix split bio been throttled more than once |
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On Wed, Jul 6, 2016 at 11:06 PM, Tejun Heo <tj@kernel.org> wrote: > Hello, > > On Wed, Jul 06, 2016 at 10:58:55PM +0800, aaronlee0817 wrote: >> >But that said, can't we just copy BIO_THROTLED while splitting? >> >> In my opinion, copying BIO_THROTLED while splitting doesn't work >> with this, because, the bio within the limit will not set BIO_THROTLED >> but will be split, and back to call generic_make_request(), and will be >> count twice. > > I see. It's just a bit weird that we're marking this from clone site > when it's an issue which is specific to throttling. The thing is > depending on how bio clone is used, it could misbehave in the other
The cloned bio often need to be submitted via generic_make_request().
> direction (bio not accounted at all). What we want to know is whether > a bio has been previously accounted or not, rather than whether a bio > is a result of splitting. I think it'd be better to track that > instead.
Looks the flag of BIO_THROTLED doesn't work well, and it should have been set if the bio is accounted, and seems not related with splitting.
Thanks, Ming
> > Thanks. > > -- > tejun > -- > To unsubscribe from this list: send the line "unsubscribe linux-block" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
-- Ming Lei
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