Re: bio_add_page rw mode check by merge_bvec_fn

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 22 Nov 2013 07:36:18 -0800 Christoph Hellwig <hch@xxxxxxxxxxxxx>
wrote:

> While this is trivial to fix it's also fairly unexpected and easy
> to get wrong for new callers.  Neil, can you explain why you
> desperately need it?

Desperately?  Not at all?
Need?  Not really.  This is just in RAID5 and merge_bvec_fn is purely an
optimisation for RAID5.
Limiting read BIOs to one chunk allows us to bypass the stripe-cache, so can
be good.
Limiting write BIOs is completely unnecessary so we currently don't bother.

So I have no objection to bvm->bi_rw being removed.

Thanks,
NeilBrown

Attachment: signature.asc
Description: PGP signature


[Index of Archives]     [Reiser Filesystem Development]     [Ceph FS]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite National Park]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]     [Linux Media]

  Powered by Linux