powerpc/64s: Leave interrupts hard enabled in context switch for radix
authorNicholas Piggin <npiggin@gmail.com>
Thu, 8 Jun 2017 15:36:06 +0000 (01:36 +1000)
committerMichael Ellerman <mpe@ellerman.id.au>
Thu, 15 Jun 2017 06:34:39 +0000 (16:34 +1000)
commite4c0fc5f72bca11432297168338aef46c12793a4
treeaa687ec91b0521aa57c73572a970c139ceebd577
parentbc4f65e4cf9d6cc43e0e9ba0b8648cf9201cd55f
powerpc/64s: Leave interrupts hard enabled in context switch for radix

Commit 4387e9ff25 ("[POWERPC] Fix PMU + soft interrupt disable bug")
hard disabled interrupts over the low level context switch, because
the SLB management can't cope with a PMU interrupt accesing the stack
in that window.

Radix based kernel mapping does not use the SLB so it does not require
interrupts hard disabled here.

This is worth 1-2% in context switch performance on POWER9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
arch/powerpc/kernel/entry_64.S
arch/powerpc/kernel/process.c