Re: [PATCH v3 5/7] swap: Use bdev_read_page() / bdev_write_page()

From: Matthew Wilcox
Date: Fri Apr 25 2014 - 10:01:22 EST


On Thu, Apr 24, 2014 at 02:57:40PM -0400, Matthew Wilcox wrote:
> By calling the device driver to write the page directly, we avoid
> allocating a BIO, which allows us to free memory without allocating
> memory.

I got handed some performance numbers last night! Next time you're updating
the patch description, please use:

By calling the device driver to write the page directly, we avoid
allocating a BIO, which allows us to free memory without allocating
memory. When running a swap-heavy benchmark, system time is reduced by
about 20%.

Tested-by: Dheeraj Reddy <dheeraj.reddy@xxxxxxxxx>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@xxxxxxxxx>
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