Messages in this thread | | | Date | Fri, 24 Apr 2015 22:32:33 -0400 | From | Rik van Riel <> | Subject | Re: Interacting with coherent memory on external devices |
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On 04/21/2015 05:44 PM, Paul E. McKenney wrote:
> AUTONUMA > > The Linux kernel's autonuma facility supports migrating both > memory and processes to promote NUMA memory locality. It was > accepted into 3.13 and is available in RHEL 7.0 and SLES 12. > It is enabled by the Kconfig variable CONFIG_NUMA_BALANCING. > > This approach uses a kernel thread "knuma_scand" that periodically > marks pages inaccessible. The page-fault handler notes any > mismatches between the NUMA node that the process is running on > and the NUMA node on which the page resides.
Minor nit: marking pages inaccessible is done from task_work nowadays, there no longer is a kernel thread.
> The result would be that the kernel would allocate only migratable > pages within the CCAD device's memory, and even then only if > memory was otherwise exhausted.
Does it make sense to allocate the device's page tables in memory belonging to the device?
Is this a necessary thing with some devices? Jerome's HMM comes to mind...
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