Messages in this thread | | | Date | Wed, 6 Jan 2016 12:47:53 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH 2/2] arm64: factor work_pending state machine to C |
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On Wed, Jan 06, 2016 at 12:30:11PM +0000, Catalin Marinas wrote: > On Tue, Jan 05, 2016 at 05:33:35PM +0000, Mark Rutland wrote: > > Currently ret_fast_syscall, work_pending, and ret_to_user form an ad-hoc > > state machine that can be difficult to reason about due to duplicated > > code and a large number of branch targets. > > > > This patch factors the common logic out into the existing > > do_notify_resume function, converting the code to C in the process, > > making the code more legible. > > > > This patch tries to mirror the existing behaviour as closely as possible > > while using the usual C control flow primitives. There should be no > > functional change as a result of this patch. > > > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > > Cc: Catalin Marinas <catalin.marinas@arm.com> > > Cc: Chris Metcalf <cmetcalf@ezchip.com> > > Cc: Will Deacon <will.deacon@arm.com> > > This is definitely cleaner. The only downside is slightly more expensive > ret_fast_syscall. I guess it's not noticeable (though we could do some > quick benchmark like getpid in a loop). Anyway, I'm fine with the patch: > > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cheers!
While any additional overhead hasn't been noticeable, I'll try to get some numbers out as part of the larger deasm testing/benchmarking.
Thanks, Mark.
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