system/serenity
system/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity synced 2024-07-09 03:50:45 +00:00
Code Issues Projects Releases Wiki Activity

ResourceGraph: Use /proc/stat instead of /proc/all for CPU usage stats

Browse Source 
This results in a quite large speedup, as generating /proc/all takes a
very long time.
This commit is contained in:
Idan Horowitz 2021-10-07 22:05:31 +03:00 committed by Andreas Kling
parent 399b5ffb64
commit 350c5a751d
1 changed files with 29 additions and 29 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
Userland/Applets/ResourceGraph/main.cpp
View File

@ -44,12 +44,13 @@ private:
{
switch (m_graph_type) {
case GraphType::CPU: {
u64 busy, idle, scheduled_diff;
if (get_cpu_usage(busy, idle, scheduled_diff)) {
auto busy_diff = busy - m_last_cpu_busy;
m_last_cpu_busy = busy;
m_last_cpu_idle = idle;
float cpu = scheduled_diff > 0 ? (float)busy_diff / (float)scheduled_diff : 0;
u64 total, idle;
if (get_cpu_usage(total, idle)) {
auto total_diff = total - m_last_total;
m_last_total = total;
auto idle_diff = idle - m_last_idle;
m_last_idle = idle;
float cpu = total_diff > 0 ? (float)(total_diff - idle_diff) / (float)total_diff : 0;
m_history.enqueue(cpu);
m_tooltip = String::formatted("CPU usage: {:.1}%", 100 * cpu);
} else {
@ -117,28 +118,28 @@ private:
}
}
bool get_cpu_usage(u64& busy, u64& idle, u64& scheduled_diff)
bool get_cpu_usage(u64& total, u64& idle)
{
busy = 0;
total = 0;
idle = 0;
scheduled_diff = 0;
auto all_processes = Core::ProcessStatisticsReader::get_all(m_proc_all);
if (!all_processes.has_value() || all_processes.value().processes.is_empty())
return false;
if (m_last_total_sum.has_value())
scheduled_diff = all_processes->total_time_scheduled - m_last_total_sum.value();
m_last_total_sum = all_processes->total_time_scheduled;
for (auto& it : all_processes.value().processes) {
for (auto& jt : it.threads) {
if (it.pid == 0)
idle += jt.time_user + jt.time_kernel;
else
busy += jt.time_user + jt.time_kernel;
}
if (m_proc_stat) {
// Seeking to the beginning causes a data refresh!
if (!m_proc_stat->seek(0, Core::SeekMode::SetPosition))
return false;
} else {
auto proc_stat = Core::File::construct("/proc/stat");
if (!proc_stat->open(Core::OpenMode::ReadOnly))
return false;
m_proc_stat = move(proc_stat);
}
auto file_contents = m_proc_stat->read_all();
auto json = JsonValue::from_string(file_contents);
VERIFY(json.has_value());
auto& obj = json.value().as_object();
total = obj.get("total_time").to_u64();
idle = obj.get("idle_time").to_u64();
return true;
}
@ -176,11 +177,10 @@ private:
Gfx::Color m_graph_color;
Gfx::Color m_graph_error_color;
CircularQueue<float, history_size> m_history;
u64 m_last_cpu_busy { 0 };
u64 m_last_cpu_idle { 0 };
Optional<u64> m_last_total_sum;
u64 m_last_idle { 0 };
u64 m_last_total { 0 };
String m_tooltip;
RefPtr<Core::File> m_proc_all;
RefPtr<Core::File> m_proc_stat;
RefPtr<Core::File> m_proc_mem;
};
@ -250,7 +250,7 @@ int main(int argc, char** argv)
return 1;
}
if (unveil("/proc/all", "r") < 0) {
if (unveil("/proc/stat", "r") < 0) {
perror("unveil");
return 1;
}