From: "Jan Beulich" <JBeulich@suse.com>
To: "xen-devel" <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
Wei Liu <wei.liu2@citrix.com>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH 4/5] x86: allow limiting the max C-state sub-state
Date: Thu, 23 May 2019 06:18:47 -0600 [thread overview]
Message-ID: <5CE68FA70200007800231B3E@prv1-mh.provo.novell.com> (raw)
Message-ID: <20190523121847.024NNodCVXYv1yVK4k8kzggZxl48wVjAFTL8Vv5NbC0@z> (raw)
In-Reply-To: <5CE68CD30200007800231B01@prv1-mh.provo.novell.com>
From: Ross Lagerwall <ross.lagerwall@citrix.com>
Allow limiting the max C-state sub-state by appending to the max_cstate
command-line parameter. E.g. max_cstate=1,0
The limit only applies to the highest legal C-state. For example:
max_cstate = 1, max_csubstate = 0 ==> C0, C1 okay, but not C1E
max_cstate = 1, max_csubstate = 1 ==> C0, C1 and C1E okay, but not C2
max_cstate = 2, max_csubstate = 0 ==> C0, C1, C1E, C2 okay, but not C3
max_cstate = 2, max_csubstate = 1 ==> C0, C1, C1E, C2 okay, but not C3
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/docs/misc/xen-command-line.pandoc
+++ b/docs/misc/xen-command-line.pandoc
@@ -1369,9 +1369,11 @@ Specify the maximum number of CPUs that
This option is ignored in **pv-shim** mode.
### max_cstate (x86)
-> `= <integer>`
+> `= <integer>[,<integer>]`
-Specify the deepest C-state CPUs are permitted to be placed in.
+Specify the deepest C-state CPUs are permitted to be placed in, and
+optionally the maximum sub C-state to be used used. The latter only applies
+to the highest permitted C-state.
### max_gsi_irqs (x86)
> `= <integer>`
--- a/xen/arch/x86/acpi/cpu_idle.c
+++ b/xen/arch/x86/acpi/cpu_idle.c
@@ -104,7 +104,17 @@ bool lapic_timer_init(void)
void (*__read_mostly pm_idle_save)(void);
unsigned int max_cstate __read_mostly = UINT_MAX;
-integer_param("max_cstate", max_cstate);
+unsigned int max_csubstate __read_mostly = UINT_MAX;
+
+static int __init parse_cstate(const char *s)
+{
+ max_cstate = simple_strtoul(s, &s, 0);
+ if ( *s == ',' )
+ max_csubstate = simple_strtoul(s + 1, &s, 0);
+ return 0;
+}
+custom_param("max_cstate", parse_cstate);
+
static bool __read_mostly local_apic_timer_c2_ok;
boolean_param("lapic_timer_c2_ok", local_apic_timer_c2_ok);
@@ -347,7 +357,11 @@ static void dump_cx(unsigned char key)
printk("'%c' pressed -> printing ACPI Cx structures\n", key);
if ( max_cstate < UINT_MAX )
+ {
printk("max state: C%u\n", max_cstate);
+ if ( max_csubstate < UINT_MAX )
+ printk("max sub-state: %u\n", max_csubstate);
+ }
for_each_present_cpu ( cpu )
{
struct acpi_processor_power *power = processor_powers[cpu];
@@ -590,7 +604,13 @@ static void acpi_processor_idle(void)
do {
cx = &power->states[next_state];
- } while ( cx->type > max_state && --next_state );
+ } while ( (cx->type > max_state ||
+ cx->entry_method == ACPI_CSTATE_EM_NONE ||
+ (cx->entry_method == ACPI_CSTATE_EM_FFH &&
+ cx->type == max_cstate &&
+ (cx->address & MWAIT_SUBSTATE_MASK) > max_csubstate)) &&
+ --next_state );
+ cx = &power->states[next_state];
if ( next_state )
{
if ( cx->type == ACPI_STATE_C3 && power->flags.bm_check &&
--- a/xen/arch/x86/cpu/mwait-idle.c
+++ b/xen/arch/x86/cpu/mwait-idle.c
@@ -731,7 +731,9 @@ static void mwait_idle(void)
do {
cx = &power->states[next_state];
- } while (cx->type > max_state && --next_state);
+ } while ((cx->type > max_state || (cx->type == max_cstate &&
+ MWAIT_HINT2SUBSTATE(cx->address) > max_csubstate)) &&
+ --next_state);
if (!next_state)
cx = NULL;
else if (tb_init_done)
--- a/xen/include/xen/acpi.h
+++ b/xen/include/xen/acpi.h
@@ -141,13 +141,21 @@ void acpi_unregister_gsi (u32 gsi);
#ifdef CONFIG_ACPI_CSTATE
/*
- * Set highest legal C-state
- * 0: C0 okay, but not C1
- * 1: C1 okay, but not C2
- * 2: C2 okay, but not C3 etc.
+ * max_cstate sets the highest legal C-state.
+ * max_cstate = 0: C0 okay, but not C1
+ * max_cstate = 1: C1 okay, but not C2
+ * max_cstate = 2: C2 okay, but not C3 etc.
+
+ * max_csubstate sets the highest legal C-state sub-state. Only applies to the
+ * highest legal C-state.
+ * max_cstate = 1, max_csubstate = 0 ==> C0, C1 okay, but not C1E
+ * max_cstate = 1, max_csubstate = 1 ==> C0, C1 and C1E okay, but not C2
+ * max_cstate = 2, max_csubstate = 0 ==> C0, C1, C1E, C2 okay, but not C3
+ * max_cstate = 2, max_csubstate = 1 ==> C0, C1, C1E, C2 okay, but not C3
*/
extern unsigned int max_cstate;
+extern unsigned int max_csubstate;
static inline unsigned int acpi_get_cstate_limit(void)
{
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next prev parent reply other threads:[~2019-05-23 12:19 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-23 12:06 [PATCH 0/5] x86: CPU idle management adjustments Jan Beulich
2019-05-23 12:06 ` [Xen-devel] " Jan Beulich
2019-05-23 12:16 ` [PATCH 1/5] x86/cpuidle: switch to uniform meaning of "max_cstate=" Jan Beulich
2019-05-23 12:16 ` [Xen-devel] " Jan Beulich
2019-06-10 15:48 ` Andrew Cooper
2019-06-11 12:13 ` Jan Beulich
2019-05-23 12:17 ` [PATCH 2/5] x86/cpuidle: really use C1 for "urgent" CPUs Jan Beulich
2019-05-23 12:17 ` [Xen-devel] " Jan Beulich
2019-06-10 15:50 ` Andrew Cooper
2019-05-23 12:18 ` [PATCH 3/5] x86/AMD: make C-state handling independent of Dom0 Jan Beulich
2019-05-23 12:18 ` [Xen-devel] " Jan Beulich
2019-06-10 16:28 ` Andrew Cooper
2019-06-11 12:42 ` Jan Beulich
2019-06-18 17:22 ` Woods, Brian
2019-06-19 6:20 ` Jan Beulich
2019-06-19 15:54 ` Woods, Brian
2019-06-21 6:37 ` Jan Beulich
2019-06-21 14:29 ` Woods, Brian
2019-06-21 14:56 ` Jan Beulich
2019-06-21 15:26 ` Woods, Brian
2019-05-23 12:18 ` Jan Beulich [this message]
2019-05-23 12:18 ` [Xen-devel] [PATCH 4/5] x86: allow limiting the max C-state sub-state Jan Beulich
2019-06-10 16:43 ` Andrew Cooper
2019-06-11 12:46 ` Jan Beulich
2019-05-23 12:19 ` [PATCH 5/5] tools/libxc: allow controlling " Jan Beulich
2019-05-23 12:19 ` [Xen-devel] " Jan Beulich
2019-05-24 14:00 ` Wei Liu
2019-05-24 14:00 ` [Xen-devel] " Wei Liu
2019-06-10 16:54 ` Andrew Cooper
2019-06-11 12:50 ` Jan Beulich
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