Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:arch\x86\kernel\cpu\umwait.c Create Date:2022-07-28 07:56:51
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:max_time_store

Proto:static ssize_t max_time_store(struct device *kobj, struct device_attribute *attr, const char *buf, size_t count)

Type:ssize_t

Parameter:

TypeParameterName
struct device *kobj
struct device_attribute *attr
const char *buf
size_tcount
178  ret = kstrtou32(buf, 0, & max_time)
179  If ret Then Return ret
183  If max_time & ~The time field is bit[31:2], but representing a 32bit value with* bit[1:0] zero. Then Return -EINVAL
186  mutex_lock( & Serialize access to umwait_control_cached and IA32_UMWAIT_CONTROL MSR in* the sysfs write functions.)
188  ctrl = READ_ONCE(Cache IA32_UMWAIT_CONTROL MSR. This is a systemwide control. By default,* umwait max time is 100000 in TSC-quanta and C0.2 is enabled)
189  If max_time != umwait_ctrl_max_time(ctrl) Then umwait_update_control(max_time, When bit 0 in IA32_UMWAIT_CONTROL MSR is 1, C0.2 is disabled.* Otherwise, C0.2 is enabled.)
192  mutex_unlock( & Serialize access to umwait_control_cached and IA32_UMWAIT_CONTROL MSR in* the sysfs write functions.)
194  Return count