Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753233AbcD1Kif (ORCPT ); Thu, 28 Apr 2016 06:38:35 -0400 Received: from mga02.intel.com ([134.134.136.20]:49305 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752245AbcD1Kid (ORCPT ); Thu, 28 Apr 2016 06:38:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,546,1455004800"; d="scan'208";a="964534504" 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: [PATCH 6/6] documentation: Add scheuler/sched-avg.txt Date: Thu, 28 Apr 2016 10:56:13 +0800 Message-Id: <1461812173-32439-7-git-send-email-yuyang.du@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1461812173-32439-1-git-send-email-yuyang.du@intel.com> References: <1461812173-32439-1-git-send-email-yuyang.du@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3769 Lines: 177 This doc file has the programs to generate the constants to compute sched averages. Signed-off-by: Yuyang Du --- Documentation/scheduler/sched-avg.txt | 160 +++++++++++++++++++++++++++++++++ 1 file changed, 160 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..55fe900 --- /dev/null +++ b/Documentation/scheduler/sched-avg.txt @@ -0,0 +1,160 @@ +============================================================== + C program: +============================================================== + +#include +#include + +#define HALFLIFE 32 +#define SHIFT 32 + +/* +print " #: yN_inv yN_sum" +print "-----------------------" +y = (0.5)**(1/32.0) +x = 2**32 +xx = 1024 +for i in range(0, 32): + if i == 0: + x = x-1 + xx = xx*y + else: + x = x*y + xx = int(xx*y + 1024*y) + print "%2d: %#x %8d" % (i, int(x), int(xx)) + +print " #: sum_N32" +print "------------" +xxx = xx +for i in range(0, 11): + if i == 0: + xxx = xx + else: + xxx = xxx/2 + xx + print "%2d: %8d" % (i, xxx) +*/ + +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(); +} + +============================================================== + Python script if you speak snake +============================================================== + +#!/usr/bin/env python + +print " #: yN_inv yN_sum" +print "-----------------------" +y = (0.5)**(1/32.0) +x = 2**32 +xx = 1024 +for i in range(0, 32): + if i == 0: + x = x-1 + xx = xx*y + else: + x = x*y + xx = int(xx*y + 1024*y) + print "%2d: %#x %8d" % (i, int(x), int(xx)) + +print +print " #: sum_N32" +print "------------" +xxx = xx +for i in range(0, 11): + if i == 0: + xxx = xx + else: + xxx = xxx/2 + xx + print "%2d: %8d" % (i, xxx) + +print +print " n: max" +print "------------" +xxxx = 1024 +old = 0 +i = 2 +while (1): + xxxx = int(xxxx*y + 1024) + if old == xxxx: + break + i = i+1 + old = xxxx +print "%3d: %7d" % (i-1, xxxx) -- 1.7.9.5