Re: [PATCH] eal/armv8: high-resolution cycle counter
flat view
From: Jerin Jacob <hidden>
Date: 2016-08-19 12:52:39
On Fri, Aug 19, 2016 at 02:24:58PM +0200, Jan Viktorin wrote:
On Fri, 19 Aug 2016 17:16:12 +0530 Jerin Jacob [off-list ref] wrote: I've got a private kernel driver enabling and disabling (hopefully) properly this for ARMv7. If we'd like to merge it, I'd like to have a single module or at least single module with 2 implementations... I can post it if it would be helpful.
I don't think we can use this in production as this may alter PMU state used by 'perf' etc.I think let it be a debug interface for armv7 and armv8 and disable it by default.
quoted hunk ↗ jump to hunk
Regards Janquoted
quoted
quoted
+ * + */ +static inline uint64_t +rte_rdtsc(void) +{ + uint64_t tsc; + + asm volatile("mrs %0, pmccntr_el0" : "=r"(tsc)); + return tsc; +} +#endif static inline uint64_t rte_rdtsc_precise(void) -- 2.5.5Do you also plan to support performance monitor event counters?No. This patch was inspired by armv7 PMU scheme and its part of DPDK. The sole reason to add this support to catch any performance regression through app/test application.Other than that, I think cntvct_el0 based existing scheme is good enough for all the use cases.quoted
Regards, Nipun-- Jan Viktorin E-mail: Viktorin@RehiveTech.com System Architect Web: www.RehiveTech.com RehiveTech Brno, Czech Republic