On Wed, 2013-04-24 at 23:54 +0200, Paolo Bonzini wrote: > Il 24/04/2013 23:02, James Bottomley ha scritto: > > That just leaves us with random standards behaviour. Lets permit the > > deterministic thing instead for the distros. It kills two birds with > > one stone because we can set WCE for the stupid UAS devices that clear > > it wrongly as well. > > > > For those who don't read code well, you add a temporary prefix to the > > cache set in > > > > echo xxx > /sys/class/scsi_disk/<disk>/cache_type > > > > and it will set the flags for the lifetime of the current kernel, but > > won't try to do a mode select to make them permanent. > > Having the knob is useful indeed. I don't like the "temporary" name > though, because "temporary write-through" doesn't sound like it can eat > data on a power loss. What about "force" or "assume"? I'm fairly ambivalent, except not force. The default behaviour is to do the mode select, so force seems to imply that as well, except it won't. I don't see a difference between assume and temporary. > Also, this would be in addition to my patch (when tested), right? Not really ... given T10s deprecation I don't think we want to touch anything to do with SYNC_NV because it just adds to the uncertainty about what will actually happen. Giving the ability to control WCE (and RCD) fixes all the problems raised so far. James -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
