Re: [PATCH 5/6] f2fs: add a kernel thread to issue discard commands asynchronously

[Christoph Hellwig]

On Mon, Jan 16, 2017 at 09:32:20AM -0800, Christoph Hellwig wrote:
> On Fri, Jan 13, 2017 at 11:12:11AM -0800, Jaegeuk Kim wrote:
> > Previously, I've done to issue discard bios asynchronously. But the problem that
> > I've got is that was not enough. When testing nvme SSD with noop IO scheduler,
> > submit_bio() was blocked at every 8 async discard bios, resulting in very slow
> > checkpoint process which blocks most of other FS operations.
> 
> Where does it block?  Are you running out of request?  What driver is
> this on top of?

Ping?  I'm currently spending a lot of effort on fs and block dÑscard
code, and I'd like to make sure we get common infrastructure instead
of local hacks.