Re: [PATCH 13/14] target/rd: Add DIF protection into rd_execute_rw

[Nicholas A. Bellinger]

On Sun, 2014-01-12 at 13:53 +0200, Sagi Grimberg wrote:
> <SNIP>
> 
> >> I wander how we can skip  sbc_dif_verify_xxxx if the transport already
> >> offloaded DIF verify.
> >> I think that the transport should signal the core layer that it is able
> >> to offload DIF (ADD/STRIP/PASS/VERIFY), in which case the core should
> >> turn off the backstore DIF verify emulation to sustain performance.
> > So IBLOCK + PSCSI backends will need to be a non interleaved protection
> > PASS for fast path operation, and backend protection emulation is
> > reserved for RAMDISK and perhaps a special FILEIO full emulation mode.
> 
> But can't we avoid that if transport already verified? This will kill 
> performance.
> 

Sure, this will end up being configurable per backend if the fabric does
a CHECK + STRIP, or CHECK + PASS.

--nab



--
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/