Re: [PATCHv8 5/8] mm: break up swap_writepage() for frontswap backends

From: Seth Jennings
Date: Thu Apr 04 2013 - 18:30:54 EST


On 04/04/2013 05:10 PM, Seth Jennings wrote:
> swap_writepage() is currently where frontswap hooks into the swap
> write path to capture pages with the frontswap_store() function.
> However, if a frontswap backend wants to "resume" the writeback of
> a page to the swap device, it can't call swap_writepage() as
> the page will simply reenter the backend.
>
> This patch separates swap_writepage() into a top and bottom half, the
> bottom half named __swap_writepage() to allow a frontswap backend,
> like zswap, to resume writeback beyond the frontswap_store() hook.
>
> __add_to_swap_cache() is also made non-static so that the page for
> which writeback is to be resumed can be added to the swap cache.
>
> Acked-by: Minchan Kim <minchan@xxxxxxxxxx>
> Signed-off-by: Seth Jennings <sjenning@xxxxxxxxxxxxxxxxxx>

Adding Cc Bob Liu.

I just remembered that Bob had done a repost of the 5 and 6 patches,
outside the zswap thread, with a small change to avoid a checkpatch
warning. I didn't pull that change into my version, but I should have.

It doesn't make a functional difference, so this patch can still go
forward and the checkpatch warning can be cleaned up in a subsequent
patch. If another revision of the patchset is needed for other
reasons, I'll pull this change into the next version.

I think Dan and Bob would be ok with their tags being applied to 5 and 6:

Acked-by: Bob Liu <bob.liu@xxxxxxxxxx>
Reviewed-by: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>

That ok?

Thanks,
Seth

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