On 23/08/13 10:26, Catalin Marinas wrote: > On Tue, Aug 20, 2013 at 06:14:52PM +0100, Sudeep KarkadaNagesha wrote: >> On 13/08/13 18:29, Sudeep KarkadaNagesha wrote: >>> From: Sudeep KarkadaNagesha <[email protected]> >>> >>> This patch series adds support to configure the rate and enable the >>> event stream for architected timer. The event streams can be used to >>> impose a timeout on a WFE, to safeguard against any programming error >>> in case an expected event is not generated or even to implement >>> wfe-based timeouts for userspace locking implementations. >>> >>> Since the timer control register is reset to zero on warm boot, CPU >>> PM notifier is added to re-initialize it. >>> >>> Changes v2->v3: >>> 1. Moved ARM and ARM64 changes into separate patches >>> 2. Added native hwcaps definations(ARM/ARM64) and compat-specific >>> definitions(ARM64) to the users for the event stream feature. >> >> Can you review this version of the series ? > > I think the series is OK with the follow-up comments addressed. Could > you please post a v4 to make sure I haven't missed anything? > > Another comment I have is whether we should make this feature > configurable. The reason is mainly hardware validation: if some CPU > implementation messes the event generation (and on ARMv8 it's a bit more > complex as this is tied to the exclusive monitor) we risk not detecting > it because of the event stream.
Yes that seems reasonable. I assume we can enable it by default and we need to disable it for hardware validation. Let me know if think otherwise. Regards, Sudeep -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
