LOR on nfs: vfs_vnops.c:301 kern_descrip.c:1580

[Rick Macklem]

> On 18 August 2010 12:07, pluknet <pluknet at gmail.com> wrote:
> > On 17 August 2010 20:04, Kostik Belousov <kostikbel at gmail.com> wrote:
> >
> >>
> >> Also please take a note of the John' suggestion to use the taskqueue.
> >
> > I decided to go this road. Thank you both.
> > Now I do nfs buildkernel survive and prepare some benchmark results.
> >
> 
I'm away from home, so I can only do email and haven't looked at the
patch, but I think you might want to consider avoiding the malloc()
failure by calling malloc(... M_WAITOK); before grabbing the mutex.
Then, set the pointer to NULL if you use it and free it at the end
(I tend to test for non-NULL before calling free(), but others have
pointed out that this isn't necessary.)

I believe this is called "Dykstra's technique", although I used it
a lot before I found out it had been published.

I think handling the case where malloc() fails correctly could
be difficult which is why I suggested the above.

Good luck with the patch, rick