| Message ID | 35ab0d0a-f9ce-b4d7-cd85-3cd8a8638ab6@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [1/2] cpupower: fix amd cpu (family < 0x17) active state issue | expand |
On 3/24/21 4:27 AM, xufuhai wrote: > From: xufuhai <xufuhai@kuaishou.com> > > For the old AMD processor (family < 0x17), cpupower will call the > amd_pci_get_num_boost_states function, but for the non-root user > pci_read_byte function (implementation comes from the psutil library), > val will be set to 0xff, indicating that there is no read function > callback. At this time, the original logic will set the cpupower turbo > active state to yes. This is an obvious issue~ > Please run get_maintainer.pl and send patch maintainers and others suggested by the tool. I don't see this in my Inbox for me to review/accept and send it to pm maintainer. Hmm. I am seeing on my AMD as non-root current CPU frequency: Unable to call hardware as root current CPU frequency: 3.60 GHz (asserted by call to hardware) Are you sure this change is necessary? Please give me more information on this fix. > Reproduce procedure: > cpupower frequency-info > > Signed-off-by: xufuhai <xufuhai@kuaishou.com> > Signed-off-by: chenguanqiao <chenguanqiao@kuaishou.com> > Signed-off-by: lishujin <lishujin@kuaishou.com> > --- > tools/power/cpupower/utils/helpers/amd.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c > index 97f2c857048e..6f9504906afa 100644 > --- a/tools/power/cpupower/utils/helpers/amd.c > +++ b/tools/power/cpupower/utils/helpers/amd.c > @@ -137,6 +137,13 @@ int amd_pci_get_num_boost_states(int *active, int *states) > return -ENODEV; > > val = pci_read_byte(device, 0x15c); > + > + /* If val is 0xff, meaning has no permisson to Typo: permisson. Reads better as "0xff indicates user doesn't have permission to read boot states" > + * get the boost states, return -1 > + */ > + if (val == 0xff) > + return -1; > + > if (val & 3) > *active = 1; > else > thanks, -- Shuah
yeah Shuah~ thanks for your reply
For this issue, not meaning "current CPU frequency" but "boost state support--->Active" during
"cpupower frequency-info" command as below:
boost state support:
Supported: yes
Active: yes/no
I think the state returned from the command for amd cpu (family < 0x17) should be like as below:
as non-root Active state:
Active: Error while evaluating Boost Capabilities on CPU xx -- are you root?
as root Active state:
Active: yes (if supported)
no (if not supprted)
I don't wanna see the state returned like below:
as non-root Active state:
Active: yes
as root Active state:
Active: yes (if supported)
no (if not supprted)
I will paste the related code by detailed for showing the issue:
if amd cpu family < 0x17 , will run amd_pci_get_num_boost_states function:
-----------------------------------------------------
/linux/tools/power/cpupower/utils/helper/misc.c
if (cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_CPB) {
*support = 1;
/* AMD Family 0x17 does not utilize PCI D18F4 like prior
* families and has no fixed discrete boost states but
* has Hardware determined variable increments instead.
*/
if (cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_CPB_MSR) {
if (!read_msr(cpu, MSR_AMD_HWCR, &val)) {
if (!(val & CPUPOWER_AMD_CPBDIS))
*active = 1;
}
} else {
ret = amd_pci_get_num_boost_states(active, states);
if (ret)
return ret;
}
---------------------------------------------------
/linux/tools/power/cpupower/utils/helper/amd.c
amd_pci_get_num_boost_states:
val = pci_read_byte(device, 0x15c);
if (val & 3)
*active = 1;
else
----------------------------------------------------
pci_read_byte will memset val to 0xff if caller has no permission to access to read from pci_dev
but for amd_pci_get_num_boost_states, active state will set 1 meaning "yes". I believe that active
state should return negative value to caller function meaning "have no permission" will showing "
Error while evaluating Boost Capabilities on CPU xx -- are you root?"
----------------------------------------------------
static inline void
pci_read_data(struct pci_dev *d, void *buf, int pos, int len)
{
if (pos & (len-1))
d->access->error("Unaligned read: pos=%02x, len=%d", pos, len);
if (pos + len <= d->cache_len)
memcpy(buf, d->cache + pos, len);
else if (!d->methods->read(d, pos, buf, len))
memset(buf, 0xff, len);
}
byte
pci_read_byte(struct pci_dev *d, int pos)
{
byte buf;
pci_read_data(d, &buf, pos, 1);
return buf;
}
----------------------------------------------------
在 2021/3/24 下午6:27, xufuhai 写道:
> From: xufuhai <xufuhai@kuaishou.com>
>
> For the old AMD processor (family < 0x17), cpupower will call the
> amd_pci_get_num_boost_states function, but for the non-root user
> pci_read_byte function (implementation comes from the psutil library),
> val will be set to 0xff, indicating that there is no read function
> callback. At this time, the original logic will set the cpupower turbo
> active state to yes. This is an obvious issue~
>
> Reproduce procedure:
> cpupower frequency-info
>
> Signed-off-by: xufuhai <xufuhai@kuaishou.com>
> Signed-off-by: chenguanqiao <chenguanqiao@kuaishou.com>
> Signed-off-by: lishujin <lishujin@kuaishou.com>
> ---
> tools/power/cpupower/utils/helpers/amd.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c
> index 97f2c857048e..6f9504906afa 100644
> --- a/tools/power/cpupower/utils/helpers/amd.c
> +++ b/tools/power/cpupower/utils/helpers/amd.c
> @@ -137,6 +137,13 @@ int amd_pci_get_num_boost_states(int *active, int *states)
> return -ENODEV;
>
> val = pci_read_byte(device, 0x15c);
> +
> + /* If val is 0xff, meaning has no permisson to
> + * get the boost states, return -1
> + */
> + if (val == 0xff)
> + return -1;
> +
> if (val & 3)
> *active = 1;
> else
>
diff --git a/tools/power/cpupower/utils/helpers/amd.c b/tools/power/cpupower/utils/helpers/amd.c index 97f2c857048e..6f9504906afa 100644 --- a/tools/power/cpupower/utils/helpers/amd.c +++ b/tools/power/cpupower/utils/helpers/amd.c @@ -137,6 +137,13 @@ int amd_pci_get_num_boost_states(int *active, int *states) return -ENODEV; val = pci_read_byte(device, 0x15c); + + /* If val is 0xff, meaning has no permisson to + * get the boost states, return -1 + */ + if (val == 0xff) + return -1; + if (val & 3) *active = 1; else