Tejun Heo wrote:
Alan Cox wrote:
Not that simple. Most disks don't spin up on SYNCHRONIZE_CACHE if
its cache is clean. Sadly some disks actually spin up when it
receives spin down command while spun down to immediately spin down
again, so we would be fixing problem for some number of disks while
breaking others. :-(
Snoop the last command sent to the drive, that tells you if you can skip
the cache flush ?
Thought about that and querying power state before doing shutdown
sequence but things get somewhat ugly because shutdown sequence is
driven from sd->shutdown(). We'll have to snoop both sync and shutdown
commands and check whether the system is shutting down. Also, I felt
very uneasy about faking successful completion to SYNCHRONIZE_CACHE.
I dunno. It's already too late for 2.6.21. I was hoping we could get
distros to update shutdown utilities in not-too-distant future but I
have no experience with that. Is that just a wishful thinking?
FWIW, the the following message describes the proposed solution.
http://thread.gmane.org/gmane.linux.scsi/30487/focus=17392
--
tejun
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
