Messages in this thread | | | Date | Wed, 28 Jan 2015 11:58:18 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH v3 1/2] x86: Add support for the pcommit instruction |
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On Tue, Jan 27, 2015 at 09:53:50AM -0700, Ross Zwisler wrote: > Add support for the new pcommit (persistent commit) instruction. This > instruction was announced in the document "Intel Architecture > Instruction Set Extensions Programming Reference" with reference number > 319433-022. > > https://software.intel.com/sites/default/files/managed/0d/53/319433-022.pdf > > The pcommit instruction ensures that data that has been flushed from the > processor's cache hierarchy with clwb, clflushopt or clflush is accepted to > memory and is durable on the DIMM. The primary use case for this is persistent > memory. > > This function shows how to properly use clwb/clflushopt/clflush and > pcommit with appropriate fencing:
...
> This is still correct, but now you've got two fences separated by only a > nop. With the commit and the fence together in pcommit_sfence() you > avoid the final unneeded fence. > > Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> > Cc: H Peter Anvin <h.peter.anvin@intel.com> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Borislav Petkov <bp@alien8.de>
Acked-by: Borislav Petkov <bp@suse.de>
-- Regards/Gruss, Boris.
ECO tip #101: Trim your mails when you reply. --
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