Re: [PATCH 1/6] block: add support for carrying a stream ID in a bio

[Matias Bjørling]

On 03/24/2015 04:26 PM, Jens Axboe wrote:
> The top bits of bio->bi_flags are reserved for keeping the
> allocation pool, set aside the next four bits for carrying
> a stream ID. That leaves us with support for 15 streams,
> 0 is reserved as a "stream not set" value.

15 streams seem very limited. Can this be extended? e.g. 16 bits.

15 streams is enough for 1-4 applications. More, and applications starts 
to fight over the same stream id's, leading them to place different age 
data in same flash blocks and push us back to square one.

I understand that Samsung multi-stream SSD supports a limited amount of 
streams, more advance implementations should provide higher limits.

Thanks,
Matias
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/