[PATCH] arm: asid: Do not replace active_asids if already 0

[Karl Mehltretter]

On Thu, Jan 04, 2018 at 06:04:05PM +0100, Catalin Marinas wrote:
> This patch changes the xchg to cmpxchg so that the active_asids is only
> updated if non-zero to avoid a race with an ASID roll-over on a
> different CPU.
> 
> Cc: Russell King <linux at armlinux.org.uk>
> Cc: Will Deacon <will.deacon at arm.com>
> Signed-off-by: Catalin Marinas <catalin.marinas at arm.com>
> ---
> 
> This is similar to the arm64 patch [1], with the difference that non-relaxed
> (cmp)xchg is used as per the existing code.
> 
> [1] http://lkml.kernel.org/r/20180104111721.33834-1-catalin.marinas at arm.com
> 

Hello Catalin,

While the arm64 patch was reviewed and merged, this patch never got any reply.
It needs a small rebase, but the change itself still applies today.

Would you like to resend it ? 

Thanks,
Karl