From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id E7A9145A6D; Tue, 1 Oct 2024 00:12:58 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 2952840655; Tue, 1 Oct 2024 00:12:54 +0200 (CEST) Received: from mail-ed1-f53.google.com (mail-ed1-f53.google.com [209.85.208.53]) by mails.dpdk.org (Postfix) with ESMTP id 031B540613 for ; Tue, 1 Oct 2024 00:12:52 +0200 (CEST) Received: by mail-ed1-f53.google.com with SMTP id 4fb4d7f45d1cf-5c87853df28so5419826a12.3 for ; Mon, 30 Sep 2024 15:12:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1727734371; x=1728339171; darn=dpdk.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=rLix56z0IQVOvgPLY8l1f/7MCsfkWiRmVz12Cui2xMI=; b=J+WESFYmGyn+RK29EU+m4bt5eXzfm1iUaNXhmXnUD5JnrMjxDqxJumYfzn98Vwnryp 1t0ManWdcWvmeSPD//oZlTznfWGjc8XhwMk3wwF5aFWifdPPHQjr9+KE23HLaEo9mWxA jTUQ1KGls9BydWt5SLURSCG8EBsRznJLinnWPGGU20cdfdexBtjQdZ2gTuRTml/MJYtr uviqfH8Zf+K5YFp1nvvlAGzu3FL2nHPhNLnQ5h+6ijpR97DE6G5JFa9lWSQfG9scHaq/ GMx4RD9xjT9iYQKUJ9xGnKZ0M4LUKeC5ZiAoCx2kaKRs2ojP/OSgmK3HsiYYYS0YCN9H e4NA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727734371; x=1728339171; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=rLix56z0IQVOvgPLY8l1f/7MCsfkWiRmVz12Cui2xMI=; b=hNtbytWKjsOZzjH6EdknYzW8XUrkDSzbzdB16GIaZ8j0+b0+mTO2Suj7fxZ3NwNfnB XyXPlOeV6RlxN0Jz5AAFXxG94IabXGqfpxZg72PA/lhpciKwhzHuDLlStm+zOq2WiX6n 9XjpWiWsQ/HKPIlZvSnjkTvtpYe6Z++eyd/atXZSn5BuLMaYZd6S2531YRoS6KceZ5mj /KtoUIoHHjSXTl7262cHtg5cDLYO0nhEXQAAMsVnHyPTnRoxZu+M3qr06qGlI0ypvBzX aDnssk/ZuJgxmnMy9J8APWRF1ro2k53MBHZZ6u7AkO52No/VXdsaUGffbgrMqYI0b2qQ l0QQ== X-Gm-Message-State: AOJu0Yyc7ZxKcOfGQA+Simnxb8RwiSEsNaK8Uy3YmZ50ThRHNKAq17Lc 7GBPylBX1dTl3c6eyAXlpT43PFoUUYccoDD6NijUX+piYurgRHDnmC6wyX/Z X-Google-Smtp-Source: AGHT+IF07b1J8kuufQ2E/OWsw/O9u3xhk6bunaovTu8ku9akjtRnVhaAWvNl0rmvEd5DcI2ubFnHQA== X-Received: by 2002:a05:6402:518b:b0:5c8:957a:b1e2 with SMTP id 4fb4d7f45d1cf-5c8957ab4d9mr4703829a12.0.1727734370731; Mon, 30 Sep 2024 15:12:50 -0700 (PDT) Received: from localhost.localdomain ([176.12.188.220]) by smtp.googlemail.com with ESMTPSA id 4fb4d7f45d1cf-5c88240a341sm5247561a12.24.2024.09.30.15.12.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Sep 2024 15:12:50 -0700 (PDT) From: Isaac Boukris To: dev@dpdk.org Cc: stephen@networkplumber.org, bruce.richardson@intel.com, roretzla@linux.microsoft.com, dmitry.kozliuk@gmail.com, david.marchand@redhat.com, Isaac Boukris Subject: [PATCH v2 2/2] timer/linux/x86: override TSC freq if no tsc_known_freq Date: Tue, 1 Oct 2024 01:08:32 +0300 Message-ID: <20240930221153.268251-3-iboukris@gmail.com> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240930221153.268251-1-iboukris@gmail.com> References: <20240921140022.107239-1-iboukris@gmail.com> <20240930221153.268251-1-iboukris@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org If the tsc_known_freq cpu flag is missing, it means the kernel doesn't trust it and calculates its own. We should do the same to avoid drift. Signed-off-by: Isaac Boukris --- lib/eal/common/eal_common_timer.c | 3 +- lib/eal/common/eal_private.h | 2 +- lib/eal/freebsd/eal_timer.c | 5 +++- lib/eal/linux/eal_timer.c | 50 +++++++++++++++++++++++++++++-- lib/eal/windows/eal_timer.c | 5 +++- 5 files changed, 58 insertions(+), 7 deletions(-) diff --git a/lib/eal/common/eal_common_timer.c b/lib/eal/common/eal_common_timer.c index c5c4703f15..e00be0a5c8 100644 --- a/lib/eal/common/eal_common_timer.c +++ b/lib/eal/common/eal_common_timer.c @@ -66,8 +66,7 @@ set_tsc_freq(void) } freq = get_tsc_freq_arch(); - if (!freq) - freq = get_tsc_freq(); + freq = get_tsc_freq(freq); if (!freq) freq = estimate_tsc_freq(); diff --git a/lib/eal/common/eal_private.h b/lib/eal/common/eal_private.h index af09620426..bb315dab04 100644 --- a/lib/eal/common/eal_private.h +++ b/lib/eal/common/eal_private.h @@ -374,7 +374,7 @@ void set_tsc_freq(void); * * This function is private to the EAL. */ -uint64_t get_tsc_freq(void); +uint64_t get_tsc_freq(uint64_t arch_hz); /** * Get TSC frequency if the architecture supports. diff --git a/lib/eal/freebsd/eal_timer.c b/lib/eal/freebsd/eal_timer.c index 3dd70e24ba..5a8aea03e1 100644 --- a/lib/eal/freebsd/eal_timer.c +++ b/lib/eal/freebsd/eal_timer.c @@ -26,12 +26,15 @@ enum timer_source eal_timer_source = EAL_TIMER_TSC; uint64_t -get_tsc_freq(void) +get_tsc_freq(uint64_t arch_hz) { size_t sz; int tmp; uint64_t tsc_hz; + if (arch_hz) + return arch_hz; + sz = sizeof(tmp); tmp = 0; diff --git a/lib/eal/linux/eal_timer.c b/lib/eal/linux/eal_timer.c index f56a7ae15b..9a38e47ba3 100644 --- a/lib/eal/linux/eal_timer.c +++ b/lib/eal/linux/eal_timer.c @@ -5,9 +5,9 @@ #include #include +#include #ifdef RTE_LIBEAL_USE_HPET #include -#include #include #include #endif @@ -187,8 +187,40 @@ rte_eal_hpet_init(int make_default) } #endif +/* Check if the kernel deems the arch provided TSC frequency trustworthy. */ + +static bool +is_tsc_known_freq(void) +{ + char line[2048]; + FILE *stream; + bool ret = true; /* Assume tsc_known_freq */ + +#if defined(RTE_ARCH_X86) + stream = fopen("/proc/cpuinfo", "r"); + if (!stream) { + EAL_LOG(WARNING, "Unable to open /proc/cpuinfo"); + return ret; + } + + while (fgets(line, sizeof(line), stream)) { + if (strncmp(line, "flags", 5) != 0) + continue; + + if (!strstr(line, "tsc_known_freq")) + ret = false; + + break; + } + + fclose(stream); +#endif + + return ret; +} + uint64_t -get_tsc_freq(void) +get_tsc_freq(uint64_t arch_hz) { #ifdef CLOCK_MONOTONIC_RAW #define NS_PER_SEC 1E9 @@ -199,6 +231,9 @@ get_tsc_freq(void) struct timespec t_start, t_end; uint64_t tsc_hz; + if (arch_hz && is_tsc_known_freq()) + return arch_hz; + if (clock_gettime(CLOCK_MONOTONIC_RAW, &t_start) == 0) { uint64_t ns, end, start = rte_rdtsc(); nanosleep(&sleeptime,NULL); @@ -209,6 +244,17 @@ get_tsc_freq(void) double secs = (double)ns/NS_PER_SEC; tsc_hz = (uint64_t)((end - start)/secs); + + if (arch_hz) { + /* Make sure we're within 1% for sanity check */ + if (arch_hz - tsc_hz > arch_hz / 100) + return arch_hz; + + EAL_LOG(DEBUG, "Refined architecture frequency %"PRIu64 + " to measured frequency %"PRIu64".", + arch_hz, tsc_hz); + } + /* Round up to 100Khz. 1E5 ~ 100Khz */ return RTE_ALIGN_MUL_NEAR(tsc_hz, CYC_PER_100KHZ); } diff --git a/lib/eal/windows/eal_timer.c b/lib/eal/windows/eal_timer.c index b070cb7751..cfd6c267ac 100644 --- a/lib/eal/windows/eal_timer.c +++ b/lib/eal/windows/eal_timer.c @@ -49,13 +49,16 @@ rte_delay_us_sleep(unsigned int us) } uint64_t -get_tsc_freq(void) +get_tsc_freq(uint64_t arch_hz) { LARGE_INTEGER t_start, t_end, elapsed_us; LARGE_INTEGER frequency; uint64_t tsc_hz; uint64_t end, start; + if (arch_hz) + return arch_hz; + QueryPerformanceFrequency(&frequency); QueryPerformanceCounter(&t_start); -- 2.45.0