Re: [1/6] powerpc: NMI IPI improve lock primitive

2017-08-10 Thread Michael Ellerman
On Wed, 2017-08-09 at 12:41:21 UTC, Nicholas Piggin wrote: > When the NMI IPI lock is contended, spin at low SMT priority, using > loads only, and with interrupts enabled (where possible). This > improves behaviour under high contention (e.g., a system crash when > a number of CPUs are trying to en

[PATCH 1/6] powerpc: NMI IPI improve lock primitive

2017-08-09 Thread Nicholas Piggin
When the NMI IPI lock is contended, spin at low SMT priority, using loads only, and with interrupts enabled (where possible). This improves behaviour under high contention (e.g., a system crash when a number of CPUs are trying to enter the debugger). Signed-off-by: Nicholas Piggin --- arch/power