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| author | Denis Vlasenko | 2007-06-10 18:04:54 +0000 |
|---|---|---|
| committer | Denis Vlasenko | 2007-06-10 18:04:54 +0000 |
| commit | b1e5addfedf9de4bf5dfa910756747b2b4c1f2bd (patch) | |
| tree | 7ae41a8cc5b53a8d3e771b71e00a6ae64ce5127d /procps | |
| parent | 5a65447e3090908b4bad645c84e37298ca7a7449 (diff) | |
| download | busybox-b1e5addfedf9de4bf5dfa910756747b2b4c1f2bd.zip busybox-b1e5addfedf9de4bf5dfa910756747b2b4c1f2bd.tar.gz | |
top: improve global CPU percentage (smaller & faster code)
Diffstat (limited to 'procps')
| -rw-r--r-- | procps/Config.in | 4 | ||||
| -rw-r--r-- | procps/top.c | 20 |
2 files changed, 16 insertions, 8 deletions
diff --git a/procps/Config.in b/procps/Config.in index cd46a34..fba9e40 100644 --- a/procps/Config.in +++ b/procps/Config.in @@ -109,11 +109,11 @@ config FEATURE_TOP_CPU_USAGE_PERCENTAGE Make top display CPU usage for each process. config FEATURE_TOP_CPU_GLOBAL_PERCENTS - bool "Show CPU global usage percentage (adds 1k byte)" + bool "Show CPU global usage percentage (adds 0.5k byte)" default y depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE help - Makes top display "CPU: n.n% us n.n% sy n.n% ni..." line. + Makes top display "CPU: NN% usr NN% sys..." line. config UPTIME bool "uptime" diff --git a/procps/top.c b/procps/top.c index 6d8dfd8..564e943 100644 --- a/procps/top.c +++ b/procps/top.c @@ -292,8 +292,15 @@ static unsigned long display_generic(int scr_width) /* * xxx% = (jif.xxx - prev_jif.xxx) / (jif.total - prev_jif.total) * 100% */ -#define CALC_STAT(xxx) div_t xxx = div(1000 * (jif.xxx - prev_jif.xxx) / total_diff, 10) -#define SHOW_STAT(xxx) xxx.quot, '0'+xxx.rem + /* using (unsigned) cast to make multiplication cheaper: */ +#define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff +#define SHOW_STAT(xxx) xxx +#define FMT "%3u%%" +// We can display fractional percents, but at least in glibc div() is a _function_ +// and generated code is really awful and big (+0.5k more code): +//#define CALC_STAT(xxx) div_t xxx = div(1000 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff, 10) +//#define SHOW_STAT(xxx) xxx.quot, '0'+xxx.rem +//#define FMT "%3u.%c%%" unsigned total_diff = (jif.total - prev_jif.total ? : 1); CALC_STAT(usr); CALC_STAT(sys); @@ -305,10 +312,10 @@ static unsigned long display_generic(int scr_width) //CALC_STAT(steal); snprintf(scrbuf, scr_width, - /* %3u.%c in practice almost never displays "100.0" - * and thus has implicit leading space: " 99.6" */ - "CPU:%3u.%c%% us%3u.%c%% sy%3u.%c%% ni%3u.%c%% id%3u.%c%% wa%3u.%c%% hi%3u.%c%% si", - // %3u.%c%%st", - what is this 'steal' thing? + /* %3u in practice almost never displays "100" + * and thus has implicit leading space: " 99" */ + "CPU:"FMT" usr"FMT" sys"FMT" nice"FMT" idle"FMT" wait"FMT" irq"FMT" softirq", + // FMT" steal", - what is this 'steal' thing? // I doubt anyone needs to know it SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle), SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq) @@ -317,6 +324,7 @@ static unsigned long display_generic(int scr_width) puts(scrbuf); #undef SHOW_STAT #undef CALC_STAT +#undef FMT } snprintf(scrbuf, scr_width, "Load average: %s", buf); |