Re: [RFC PATCH 1/2] bdi: Create a flag to indicate that a backing device needs stable page writes

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

 



>>>>> "Neil" == NeilBrown  <neilb@xxxxxxx> writes:

Neil,

>> Might be nice to make the sysfs knob tweakable. Also, don't forget to
>> add a suitable blurb to Documentation/ABI/.

Neil>  It isn't at all clear to me that having the sysfs knob
Neil>  'tweakable' is a good idea.  From the md/raid5 perspective, I
Neil>  would want to know for certain whether the pages in a give bio
Neil>  are guaranteed not to change, or if they might.  I could set the
Neil>  BDI_CAP_STABLE_WRITES and believe they will never change, or test
Neil>  the BDI_CAP_STABLE_WRITES and let that tell me if they might
Neil>  change or not.  But if the bit can be changed at any moment, then
Neil>  it can never be trusted and so becomes worthless to me.

I was mostly interested in being able to turn it on for devices that
haven't explicitly done so. I agree that turning it off can be
problematic.

-- 
Martin K. Petersen	Oracle Linux Engineering
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux