From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753360AbcEPClO (ORCPT ); Sun, 15 May 2016 22:41:14 -0400 Received: from mga01.intel.com ([192.55.52.88]:48632 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753160AbcEPClB (ORCPT ); Sun, 15 May 2016 22:41:01 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,625,1455004800"; d="scan'208";a="807306302" From: Yuyang Du To: peterz@infradead.org, mingo@kernel.org, linux-kernel@vger.kernel.org Cc: bsegall@google.com, pjt@google.com, morten.rasmussen@arm.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, juri.lelli@arm.com, Yuyang Du Subject: [RFC PATCH 2/9] documentation: Add scheduler/sched-avg.txt Date: Mon, 16 May 2016 02:59:27 +0800 Message-Id: <1463338774-3324-3-git-send-email-yuyang.du@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1463338774-3324-1-git-send-email-yuyang.du@intel.com> References: <1463338774-3324-1-git-send-email-yuyang.du@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This doc file has the program to generate the constants to compute sched averages. Signed-off-by: Yuyang Du --- Documentation/scheduler/sched-avg.txt | 94 +++++++++++++++++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 Documentation/scheduler/sched-avg.txt diff --git a/Documentation/scheduler/sched-avg.txt b/Documentation/scheduler/sched-avg.txt new file mode 100644 index 0000000..45be4bd --- /dev/null +++ b/Documentation/scheduler/sched-avg.txt @@ -0,0 +1,94 @@ +The following program is used to generate the constants for +computing sched averages. + +============================================================== + C program (compile with -lm) +============================================================== + +#include +#include + +#define HALFLIFE 32 +#define SHIFT 32 + +double y; + +void calc_decay_inv_multiply() { + int i; + unsigned int x; + + printf("static const u32 __decay_inv_multiply_N[] = {"); + for(i = 0; i < HALFLIFE; i++) { + x = ((1UL<<32)-1)*pow(y, i); + + if (i % 6 == 0) printf("\n\t"); + printf("0x%8x, ", x); + } + printf("\n};\n\n"); +} + +int sum = 1024; +void calc_accumulated_sum() { + int i; + + printf("static const u32 __accumulated_sum_N[] = {\n\t 0,"); + for(i = 1; i <= HALFLIFE; i++) { + if (i == 1) + sum *= y; + else + sum = sum*y + 1024*y; + + if (i % 11 == 0) printf("\n\t"); + printf("%5d,", sum); + } + printf("\n};\n\n"); +} + +int n = 1; +/* first period */ +long max = 1024; + +void calc_converged_max() { + long last = 0, y_inv = ((1UL<<32)-1)*y; + + for (; ; n++) { + if (n > 1) + max = ((max*y_inv)>>SHIFT) + 1024; + /* + * This is the same as: + * max = max*y + 1024; + */ + + if (last == max) + break; + + last = max; + } + n--; + printf("#define SCHED_AVG_HALFLIFE %d\n", HALFLIFE); + printf("#define SCHED_AVG_MAX %ld\n", max); + printf("#define SCHED_AVG_MAX_N %d\n\n", n); +} + +void calc_accumulated_sum_32() { + int i, x = sum; + + printf("static const u32 __accumulated_sum_N32[] = {\n\t 0,"); + for(i = 1; i <= n/HALFLIFE+1; i++) { + if (i > 1) + x = x/2 + sum; + + if (i % 6 == 0) printf("\n\t"); + printf("%6d,", x); + } + printf("\n};\n\n"); +} + +void main() { + y = pow(0.5, 1/(double)HALFLIFE); + + calc_decay_inv_multiply(); + calc_accumulated_sum(); + calc_converged_max(); + calc_accumulated_sum_32(); +} -- 1.7.9.5