Re: [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt()

[Dan Williams]

On Fri, May 29, 2015 at 3:59 PM, Toshi Kani <toshi.kani@xxxxxx> wrote:
> From: Toshi Kani <toshi.kani@xxxxxx>
>
> The pmem driver maps NVDIMM with ioremap_nocache() as we cannot
> write back the contents of the CPU caches in case of a crash.
>
> This patch changes to use ioremap_wt(), which provides uncached
> writes but cached reads, for improving read performance.
>
> Signed-off-by: Toshi Kani <toshi.kani@xxxxxx>

Acked-by: Dan Williams <dan.j.williams@xxxxxxxxx>

...with the caveat that I'm going to follow in behind this series with
generic ioremap_cache() enabling and converting pmem to use
persistent_copy() / persistent_sync() when the arch/cpu has persistent
memory synchronization instructions.  After the conversion
ioremap_wt() will still be there for the non-persistent_sync() capable
case.
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