id/doom3-bfg
0
0
Fork 0
mirror of https://github.com/id-Software/DOOM-3-BFG.git synced 2025-03-15 07:00:58 +00:00
Code Issues Projects Releases Packages Wiki Activity

Fix cpu clock-hz inaccuracy on linux

Browse source
This commit is contained in:
LWSS 2020-10-01 02:28:58 -07:00
parent f2a7361fc0
commit 65f7a305c1
2 changed files with 5 additions and 49 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

46
neo/sys/posix/platform_linux.cpp
View file

@ -112,57 +112,15 @@ double Sys_ClockTicksPerSecond()
static bool init = false;
static double ret;
int fd, len, pos, end;
char buf[ 4096 ];
if( init )
{
return ret;
}
fd = open( "/proc/cpuinfo", O_RDONLY );
if( fd == -1 )
{
common->Printf( "couldn't read /proc/cpuinfo\n" );
ret = MeasureClockTicks();
init = true;
common->Printf( "measured CPU frequency: %g MHz\n", ret / 1000000.0 );
return ret;
}
len = read( fd, buf, 4096 );
close( fd );
pos = 0;
while( pos < len )
{
if( !idStr::Cmpn( buf + pos, "cpu MHz", 7 ) )
{
pos = strchr( buf + pos, ':' ) - buf + 2;
end = strchr( buf + pos, '\n' ) - buf;
if( pos < len && end < len )
{
buf[end] = '\0';
ret = atof( buf + pos );
}
else
{
common->Printf( "failed parsing /proc/cpuinfo\n" );
ret = MeasureClockTicks();
init = true;
common->Printf( "measured CPU frequency: %g MHz\n", ret / 1000000.0 );
return ret;
}
common->Printf( "/proc/cpuinfo CPU frequency: %g MHz\n", ret );
ret *= 1000000;
init = true;
return ret;
}
pos = strchr( buf + pos, '\n' ) - buf + 1;
}
common->Printf( "failed parsing /proc/cpuinfo\n" );
ret = MeasureClockTicks();
init = true;
common->Printf( "measured CPU frequency: %g MHz\n", ret / 1000000.0 );
return ret;
common->Printf( "measured CPU frequency: %g MHz\n", ret / 1000000.0 );
return ret;
}
/*

8
neo/sys/posix/posix_main.cpp
View file

@ -264,11 +264,9 @@ double Sys_GetClockTicks()
#else
//#error unsupported CPU
// RB begin
struct timespec now;
clock_gettime( CLOCK_MONOTONIC, &now );
return now.tv_sec * 1000000000LL + now.tv_nsec;
uint32_t lo, hi;
__asm__ __volatile__ ( "rdtsc" : "=a" (lo), "=d" (hi));
return ( ( ( uint64_t )hi ) << 32 ) | lo;
// RB end
#endif
}