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library: trade 'float' type for a 'double', <pids> api

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While we really do not need the extra precision, we'll
trade that recently introduced float type for a double
for efficiency on a 64 bit platform. Additionally, the
UTILIZATION algorithm was tweaked producing less code.

The net result is four fewer machine instructions with
a reduction of 14 total bytes in that function's size.

Reference(s):
. introduced 'real' type & 'utilization' item
commit c69104b2b8

Signed-off-by: Jim Warner <james.warner@comcast.net>
This commit is contained in:
Jim Warner
2022-02-27 00:00:00 -06:00
committed by Craig Small
parent 831bd8cf29
commit c89421e83a
2 changed files with 8 additions and 8 deletions
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14
proc/pids.c
View File

@@ -91,7 +91,7 @@ struct pids_info {
unsigned oldflags; // the old library PROC_FILL flagss
PROCTAB *fetch_PT; // oldlib interface for 'select' & 'reap'
unsigned long hertz; // for the 'TIME' & 'UTILIZATION' calculations
float boot_seconds; // for TIME_ELAPSED & 'UTILIZATION' calculations
double boot_seconds; // for TIME_ELAPSED & 'UTILIZATION' calculations
PROCTAB *get_PT; // oldlib interface for active 'get'
struct stacks_extent *get_ext; // for active 'get' (also within 'extents')
enum pids_fetch_type get_type; // last known type of 'get' request
@@ -279,14 +279,14 @@ REG_set(TICS_SYSTEM, ull_int, stime)
setDECL(TICS_SYSTEM_C) { (void)I; R->result.ull_int = P->stime + P->cstime; }
REG_set(TICS_USER, ull_int, utime)
setDECL(TICS_USER_C) { (void)I; R->result.ull_int = P->utime + P->cutime; }
setDECL(TIME_ALL) { R->result.real = ((float)P->utime + P->stime) / I->hertz; }
setDECL(TIME_ALL_C) { R->result.real = ((float)P->utime + P->stime + P->cutime + P->cstime) / I->hertz; }
setDECL(TIME_ELAPSED) { float t = (float)P->start_time / I->hertz; R->result.real = I->boot_seconds > t ? I->boot_seconds - t : 0; }
setDECL(TIME_START) { R->result.real = (float)P->start_time / I->hertz; }
setDECL(TIME_ALL) { R->result.real = ((double)P->utime + P->stime) / I->hertz; }
setDECL(TIME_ALL_C) { R->result.real = ((double)P->utime + P->stime + P->cutime + P->cstime) / I->hertz; }
setDECL(TIME_ELAPSED) { double t = (double)P->start_time / I->hertz; R->result.real = I->boot_seconds > t ? I->boot_seconds - t : 0; }
setDECL(TIME_START) { R->result.real = (double)P->start_time / I->hertz; }
REG_set(TTY, s_int, tty)
setDECL(TTY_NAME) { char buf[64]; freNAME(str)(R); dev_to_tty(buf, sizeof(buf), P->tty, P->tid, ABBREV_DEV); if (!(R->result.str = strdup(buf))) I->seterr = 1; }
setDECL(TTY_NUMBER) { char buf[64]; freNAME(str)(R); dev_to_tty(buf, sizeof(buf), P->tty, P->tid, ABBREV_DEV|ABBREV_TTY|ABBREV_PTS); if (!(R->result.str = strdup(buf))) I->seterr = 1; }
setDECL(UTILIZATION) { float t; if (I->boot_seconds > 0) { t = I->boot_seconds - ((float)P->start_time / I->hertz); R->result.real = (float)P->utime + P->stime; R->result.real *= (100.0f / ((float)I->hertz * t)); }}
setDECL(UTILIZATION) { double t; if (I->boot_seconds > 0) { t = I->boot_seconds - ((double)P->start_time / I->hertz); R->result.real = ((double)P->utime + P->stime) * (100.0f / ((double)I->hertz * t)); }}
REG_set(VM_DATA, ul_int, vm_data)
REG_set(VM_EXE, ul_int, vm_exe)
REG_set(VM_LIB, ul_int, vm_lib)
@@ -1558,8 +1558,8 @@ PROCPS_EXPORT struct pids_fetch *procps_pids_select (
int numthese,
enum pids_select_type which)
{
double up_secs;
unsigned ids[FILL_ID_MAX + 1];
double up_secs;
int rc;
errno = EINVAL;

2
proc/pids.h
View File

@@ -214,7 +214,7 @@ struct pids_result {
unsigned long long ull_int;
char *str;
char **strv;
float real;
double real;
} result;
};