Re: Linux NFS and cached properties

[NeilBrown <neilb@suse.de>]

[-- Attachment #1: Type: text/plain, Size: 1400 bytes --]

On Thu, 16 Aug 2012 15:10:18 -0400 "J. Bruce Fields" <bfields@fieldses.org>
wrote:

> On Thu, Aug 02, 2012 at 10:04:05AM +1000, NeilBrown wrote:
> > I never liked that fact that stopping the last thread did something extra.
> > So when I added the ability to control the number of threads via sysfs I made
> 
> (You meant nfsd, not sysfs, right?  Or is there some interface I'm
> overlooking?)

Right.

> 
> > sure that it *only* controlled the number of threads.  However I kept the
> > legacy behaviour that sending SIGKILL to the nfsd threads would also unexport
> > things.  Obviously I should have documented this better.
> > 
> > The more I think out it, the more I'd really like to go back to that.  It
> > really is the *right* thing to do.
> ...
> > > > 1/ iterate through all no-sleeping threads setting a flag an increasing a
> > > > counter.
> > > > 2/ when a thread completes current request, if test_and_clear the flag, it
> > > > atomic_dec_and_test the counter and then wakes up some wait_queue_head.
> > > > 3/ 'flush'ing thread waits on the waut_queue_head for the counter to be 0.
> > > > 
> > > > If you don't hate it I could possibly even provide some code.
> 
> By the way, are you still looking into one of those approaches?

Not yet.  Other things got in the way.

I made a note to remind me when room appears in my schedule. :-)

NeilBrown

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 828 bytes --]