| Message ID | 20180808174735.3114-1-prarit@redhat.com (mailing list archive) |
|---|---|
| State | Rejected, archived |
| Delegated to: | Len Brown |
| Headers | show |
| Series | x86/ACPI/cstate: Output AMD on APCI C1 FFH MWAIT AMD systems | expand |
On Wed 2018-08-08 13:47:35, Prarit Bhargava wrote: > commit 5209654a46ee ("x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD > systems") allows use of FFH for ACPI C1 but tools like cpupower and turbostat > display INTEL for the cstate description. > > Output "AMD" for AMD systems with FFH for ACPI C1. Um, is it good idea? First, you are changing kernel API. > @@ -107,9 +108,14 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) > "Monitor-Mwait will be used to enter C-%d state\n", > cx->type); > } > - snprintf(cx->desc, > - ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > - cx->address); > + if (c->x86_vendor == X86_VENDOR_INTEL) > + snprintf(cx->desc, > + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > + cx->address); > + else > + snprintf(cx->desc, > + ACPI_CX_DESC_LEN, "ACPI FFH AMD MWAIT 0x%x", > + cx->address); Second, I read it as "Intel MWAIT" instruction is used. Yes, AMD cpu can use Intel MWAIT, too... Third, there are more CPU vendors out there. Pavel
I think it is sufficient to simply delete the "INTEL" in that string. In the unlikely event that this "change to a kernel API" breaks something, we can add it back. -Len On Wed, Aug 8, 2018 at 3:59 PM Pavel Machek <pavel@ucw.cz> wrote: > > On Wed 2018-08-08 13:47:35, Prarit Bhargava wrote: > > commit 5209654a46ee ("x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD > > systems") allows use of FFH for ACPI C1 but tools like cpupower and turbostat > > display INTEL for the cstate description. > > > > Output "AMD" for AMD systems with FFH for ACPI C1. > > Um, is it good idea? > > First, you are changing kernel API. > > > @@ -107,9 +108,14 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) > > "Monitor-Mwait will be used to enter C-%d state\n", > > cx->type); > > } > > - snprintf(cx->desc, > > - ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > > - cx->address); > > + if (c->x86_vendor == X86_VENDOR_INTEL) > > + snprintf(cx->desc, > > + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > > + cx->address); > > + else > > + snprintf(cx->desc, > > + ACPI_CX_DESC_LEN, "ACPI FFH AMD MWAIT 0x%x", > > + cx->address); > > Second, I read it as "Intel MWAIT" instruction is used. Yes, AMD cpu can > use Intel MWAIT, too... > > Third, there are more CPU vendors out there. > > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Wed 2018-08-08 16:01:41, Len Brown wrote: > I think it is sufficient to simply delete the "INTEL" in that string. > > In the unlikely event that this "change to a kernel API" breaks > something, we can add it back. I'd just leave it alone. But yes, just deleting INTEL is better than patch below. Pavel > > On Wed 2018-08-08 13:47:35, Prarit Bhargava wrote: > > > commit 5209654a46ee ("x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD > > > systems") allows use of FFH for ACPI C1 but tools like cpupower and turbostat > > > display INTEL for the cstate description. > > > > > > Output "AMD" for AMD systems with FFH for ACPI C1. > > > > Um, is it good idea? > > > > First, you are changing kernel API. > > > > > @@ -107,9 +108,14 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) > > > "Monitor-Mwait will be used to enter C-%d state\n", > > > cx->type); > > > } > > > - snprintf(cx->desc, > > > - ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > > > - cx->address); > > > + if (c->x86_vendor == X86_VENDOR_INTEL) > > > + snprintf(cx->desc, > > > + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", > > > + cx->address); > > > + else > > > + snprintf(cx->desc, > > > + ACPI_CX_DESC_LEN, "ACPI FFH AMD MWAIT 0x%x", > > > + cx->address); > > > > Second, I read it as "Intel MWAIT" instruction is used. Yes, AMD cpu can > > use Intel MWAIT, too... > > > > Third, there are more CPU vendors out there. > > > > Pavel > > -- > > (english) http://www.livejournal.com/~pavelmachek > > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html > > >
On 08/08/2018 03:58 PM, Pavel Machek wrote: > On Wed 2018-08-08 13:47:35, Prarit Bhargava wrote: >> commit 5209654a46ee ("x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD >> systems") allows use of FFH for ACPI C1 but tools like cpupower and turbostat >> display INTEL for the cstate description. >> >> Output "AMD" for AMD systems with FFH for ACPI C1. > > Um, is it good idea? >> First, you are changing kernel API. I thought about that and the AMD support was only added a year ago so I think it is okay to change. Secondly, I did a grep for the use of the desc file in the Fedora sources and only found a few places where the file is referenced. They all *report* the data but do not use it to make a decision. For example, turbostat and cpupower only return the data to the console. > >> @@ -107,9 +108,14 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) >> "Monitor-Mwait will be used to enter C-%d state\n", >> cx->type); >> } >> - snprintf(cx->desc, >> - ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", >> - cx->address); >> + if (c->x86_vendor == X86_VENDOR_INTEL) >> + snprintf(cx->desc, >> + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", >> + cx->address); >> + else >> + snprintf(cx->desc, >> + ACPI_CX_DESC_LEN, "ACPI FFH AMD MWAIT 0x%x", >> + cx->address); > > Second, I read it as "Intel MWAIT" instruction is used. Yes, AMD cpu can > use Intel MWAIT, too... That's true but the weirdness of seeing INTEL on an AMD box there made me push this patch. > > Third, there are more CPU vendors out there. Not in this code. It is AMD & Intel only. I thought about dropping INTEL, and also switching to X86. Should we drop INTEL from the above or not (as suggested later in this thread)? It feels like everyone is on the fence about it. P. > > Pavel >
>> "ACPI FFH INTEL MWAIT 0x%x" > Should we drop INTEL from the above or not (as suggested later in this thread)? > It feels like everyone is on the fence about it. Okay with me to drop the "INTEL" part of this string -- it actually doesn't add any information. thanks, -Len
diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c index dde437f5d14f..f10d3c673519 100644 --- a/arch/x86/kernel/acpi/cstate.c +++ b/arch/x86/kernel/acpi/cstate.c @@ -76,6 +76,7 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) unsigned int edx_part; unsigned int cstate_type; /* C-state type and not ACPI C-state type */ unsigned int num_cstate_subtype; + struct cpuinfo_x86 *c = &boot_cpu_data; cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &edx); @@ -107,9 +108,14 @@ static long acpi_processor_ffh_cstate_probe_cpu(void *_cx) "Monitor-Mwait will be used to enter C-%d state\n", cx->type); } - snprintf(cx->desc, - ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", - cx->address); + if (c->x86_vendor == X86_VENDOR_INTEL) + snprintf(cx->desc, + ACPI_CX_DESC_LEN, "ACPI FFH INTEL MWAIT 0x%x", + cx->address); + else + snprintf(cx->desc, + ACPI_CX_DESC_LEN, "ACPI FFH AMD MWAIT 0x%x", + cx->address); out: return retval; }
commit 5209654a46ee ("x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems") allows use of FFH for ACPI C1 but tools like cpupower and turbostat display INTEL for the cstate description. Output "AMD" for AMD systems with FFH for ACPI C1. Signed-off-by: Prarit Bhargava <prarit@redhat.com> Cc: Len Brown <lenb@kernel.org> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org Cc: linux-pm@vger.kernel.org --- arch/x86/kernel/acpi/cstate.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)