MIPS get_cycles only returns a 32 bits TSC (see timex.h). The assumption there is that the reschedule is done every 8 seconds or so. Given that tracing needs to detect delays longer than 8 seconds, we need a full 64-bits TSC, whic is provided by LTTng syntheric TSC. Signed-off-by: Mathieu Desnoyers CC: Ralf Baechle --- arch/mips/Kconfig | 2 ++ include/asm-mips/ltt.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) Index: linux-2.6-lttng/include/asm-mips/ltt.h =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ linux-2.6-lttng/include/asm-mips/ltt.h 2008-10-16 19:18:48.000000000 -0400 @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2005, Mathieu Desnoyers + * + * MIPS definitions for tracing system + */ + +#ifndef _ASM_MIPS_LTT_H +#define _ASM_MIPS_LTT_H + +#include +#include + +extern u64 ltt_read_synthetic_tsc(void); + +/* + * MIPS get_cycles only returns a 32 bits TSC (see timex.h). The assumption + * there is that the reschedule is done every 8 seconds or so. Given that + * tracing needs to detect delays longer than 8 seconds, we need a full 64-bits + * TSC, whic is provided by LTTng syntheric TSC. +*/ +static inline u32 ltt_get_timestamp32(void) +{ + return get_cycles(); +} + +static inline u64 ltt_get_timestamp64(void) +{ + return ltt_read_synthetic_tsc(); +} + +static inline void ltt_add_timestamp(unsigned long ticks) +{ } + +static inline unsigned int ltt_frequency(void) +{ + return mips_hpt_frequency; +} + +static inline u32 ltt_freq_scale(void) +{ + return 1; +} + +#endif /* _ASM_MIPS_LTT_H */ Index: linux-2.6-lttng/arch/mips/Kconfig =================================================================== --- linux-2.6-lttng.orig/arch/mips/Kconfig 2008-10-16 19:14:08.000000000 -0400 +++ linux-2.6-lttng/arch/mips/Kconfig 2008-10-16 19:16:49.000000000 -0400 @@ -1584,6 +1584,8 @@ config CPU_R4400_WORKAROUNDS config HAVE_GET_CYCLES_32 def_bool y depends on !CPU_R4400_WORKAROUNDS + select HAVE_LTT_CLOCK + select HAVE_LTT_SYNTHETIC_TSC # # Use the generic interrupt handling code in kernel/irq/: -- Mathieu Desnoyers Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/