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kernel/system_info: Avoid unnecessary usage of set_ac.

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Instead add a second level to the loop and a small temporary array.
Makes the code slightly simpler (and safer, as there is no risk
of races now.)

Also add a missing "firstCPU +" in the current_frequency calculation.
It seems that has been broken since the frequency value was introduced...
This commit is contained in:
Augustin Cavalier
2022-03-10 12:18:43 -05:00
parent 4027df884e
commit 64a051399f
1 changed files with 12 additions and 17 deletions
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src/system/kernel/system_info.cpp
+12 -17
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@@ -525,25 +525,20 @@ _get_cpu_info_etc(uint32 firstCPU, uint32 cpuCount, cpu_info* info, size_t size)
// This function is called very often from userland by applications
// that display CPU usage information, so we want to keep this as
// optimized and touch as little as possible. Hence, no use of
// a temporary buffer.
// optimized and touch as little as possible. Hence, we avoid use
// of an allocated temporary buffer.
if (IS_USER_ADDRESS(info)) {
if (user_memset(info, 0, sizeof(cpu_info) * count) != B_OK)
cpu_info local_info[8];
for (uint32 i = 0; i < count; ) {
uint32 j;
for (j = 0; i < count && j < B_COUNT_OF(local_info); i++, j++) {
local_info[j].active_time = cpu_get_active_time(firstCPU + i);
local_info[j].enabled = !gCPU[firstCPU + i].disabled;
local_info[j].current_frequency = cpu_frequency(firstCPU + i);
}
if (user_memcpy(info + (i - j), local_info, sizeof(cpu_info) * j) != B_OK)
return B_BAD_ADDRESS;
set_ac();
} else {
memset(info, 0, sizeof(cpu_info) * count);
}
for (uint32 i = 0; i < count; i++) {
info[i].active_time = cpu_get_active_time(firstCPU + i);
info[i].enabled = !gCPU[firstCPU + i].disabled;
info[i].current_frequency = cpu_frequency(i);
}
if (IS_USER_ADDRESS(info)) {
clear_ac();
}
return B_OK;