Re: [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt()
On Fri, May 29, 2015 at 3:59 PM, Toshi Kani wrote: > From: Toshi Kani > > 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 Acked-by: Dan Williams ...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. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v11 12/12] drivers/block/pmem: Map NVDIMM with ioremap_wt()
On Fri, May 29, 2015 at 3:59 PM, Toshi Kani toshi.k...@hp.com wrote: From: Toshi Kani toshi.k...@hp.com 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.k...@hp.com Acked-by: Dan Williams dan.j.willi...@intel.com ...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. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
