From: Jim Harris Date: Mon, 7 Oct 2019 15:28:21 +0000 (-0700) Subject: eal: calibrate TSC only in primary process X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=b30b134f82a19096fa096cf9bfa9822bec2e6c49;p=dpdk.git eal: calibrate TSC only in primary process This ensures secondary processes never have to calculate the TSC rate themselves, which can be noticeable in VMs that don't have access to arch-specific detection mechanism (such as CPUID leaf 0x15 or MSR 0xCE on x86). Since rte_mem_config is now internal to the EAL library, we can add tsc_hz without ABI breakage concerns. Reduces rte_eal_init() execution time in a secondary process from 165ms to 66ms on my test system. Signed-off-by: Jim Harris Acked-by: Bruce Richardson --- diff --git a/lib/librte_eal/common/eal_common_timer.c b/lib/librte_eal/common/eal_common_timer.c index 145543de77..fa9ee1b224 100644 --- a/lib/librte_eal/common/eal_common_timer.c +++ b/lib/librte_eal/common/eal_common_timer.c @@ -15,8 +15,10 @@ #include #include #include +#include #include "eal_private.h" +#include "eal_memcfg.h" /* The frequency of the RDTSC timer resolution */ static uint64_t eal_tsc_resolution_hz; @@ -77,8 +79,20 @@ estimate_tsc_freq(void) void set_tsc_freq(void) { + struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; uint64_t freq; + if (rte_eal_process_type() == RTE_PROC_SECONDARY) { + /* + * Just use the primary process calculated TSC rate in any + * secondary process. It avoids any unnecessary overhead on + * systems where arch-specific frequency detection is not + * available. + */ + eal_tsc_resolution_hz = mcfg->tsc_hz; + return; + } + freq = get_tsc_freq_arch(); if (!freq) freq = get_tsc_freq(); @@ -87,6 +101,7 @@ set_tsc_freq(void) RTE_LOG(DEBUG, EAL, "TSC frequency is ~%" PRIu64 " KHz\n", freq / 1000); eal_tsc_resolution_hz = freq; + mcfg->tsc_hz = freq; } void rte_delay_us_callback_register(void (*userfunc)(unsigned int)) diff --git a/lib/librte_eal/common/eal_memcfg.h b/lib/librte_eal/common/eal_memcfg.h index aea9a352d6..0e468bb3a7 100644 --- a/lib/librte_eal/common/eal_memcfg.h +++ b/lib/librte_eal/common/eal_memcfg.h @@ -69,6 +69,9 @@ struct rte_mem_config { uint32_t single_file_segments; /**< stored single file segments parameter. */ + uint64_t tsc_hz; + /**< TSC rate */ + uint8_t dma_maskbits; /**< Keeps the more restricted dma mask. */ };