Re: [PATCH v1 2/2] zram: remove init_lock in zram_make_request

[Sergey Senozhatsky]

On (02/02/15 10:43), Minchan Kim wrote:
> >  static inline int init_done(struct zram *zram)
> >  {
> > -	return zram->meta != NULL;
> > +	return atomic_read(&zram->refcount);
> 
> As I said previous mail, it could make livelock so I want to use disksize
> in here to prevent further I/O handling.

just as I said in my previous email -- is this live lock really possible?
we need to umount device to continue with reset. and umount will kill IOs out
of our way.

the other reset caller is  __exit zram_exit(). but once again, I don't
expect this function being executed on mounted device and module being
in use.


> > +static inline void zram_put(struct zram *zram)
> > +{
> > +	if (atomic_dec_and_test(&zram->refcount))
> > +		complete(&zram->io_done);
> > +}
> 
> Although I suggested this complete, it might be rather overkill(pz,
> understand me it was work in midnight. :))
> Instead, we could use just atomic_dec in here and
> use wait_event(event, atomic_read(&zram->refcount) == 0) in reset.
> 

yes, I think it can do the trick.

	-ss
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