Re: [PATCH v3] squashfs: Migrate from ll_rw_block usage to BIO

[Guenter Roeck]

On Wed, Nov 06, 2019 at 04:42:38PM +0900, Philippe Liard wrote:
> The ll_rw_block() function has been deprecated in favor of BIO which
> appears to come with large performance improvements.
> 
> This patch decreases boot time by close to 40% when using squashfs for
> the root file-system. This is observed at least in the context of
> starting an Android VM on Chrome OS using crosvm
> (https://chromium.googlesource.com/chromiumos/platform/crosvm). The
> patch was tested on 4.19 as well as master.
> 
> This patch is largely based on Adrien Schildknecht's patch that was
> originally sent as https://lkml.org/lkml/2017/9/22/814 though with some
> significant changes and simplifications while also taking Phillip
> Lougher's feedback into account, around preserving support for
> FILE_CACHE in particular.
> 
> Signed-off-by: Philippe Liard <pliard@xxxxxxxxxx>
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>

Hmm, I spent a lot of time reviewing this internally, but just realized that
I never sent a

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Sorry for that.

The patch still applies to current mainline. I'll run it through my test
system to give it some basic test coverage.

Guenter