Re: [PATCH v3] zram: support REQ_DISCARD

[Joonsoo Kim]

On Wed, Mar 12, 2014 at 08:03:03PM -0700, Andrew Morton wrote:
> On Thu, 13 Mar 2014 11:46:17 +0900 Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> wrote:
> 
> > +	while (n >= PAGE_SIZE) {
> > +		/*
> > +		 * discard request can be too large so that the zram can
> > +		 * be stucked for a long time if we handle the request
> > +		 * at once. So handle the request by PAGE_SIZE unit at a time.
> > +		 */
> > +		write_lock(&zram->meta->tb_lock);
> > +		zram_free_page(zram, index);
> > +		write_unlock(&zram->meta->tb_lock);
> > +		index++;
> > +		n -= PAGE_SIZE;
> > +	}
> 
> Well, you could use something like
> 
> 	if (need_resched()) {
> 		unlock()
> 		schedule()
> 		lock()
> 	}
> 
> here, or free 100 pages at a time or something silly like that.  I
> guess we retain these as options if/when that lock turns out to be
> contended.

Okay! I postpone this until that lock turns out to be contented.
Here goes new one.

Thanks.

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