From: Artem Bityutskiy <dedekind1@gmail.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Linux PM Mailing List <linux-pm@vger.kernel.org>,
chang.seok.bae@intel.com
Subject: [PATCH v1 3/3] intel_idle: add core C6 optimization for SPR
Date: Wed, 2 Mar 2022 10:16:00 +0200 [thread overview]
Message-ID: <20220302081600.1751716-3-dedekind1@gmail.com> (raw)
In-Reply-To: <20220302081600.1751716-1-dedekind1@gmail.com>
From: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Add a Sapphire Rapids Xeon C6 optimization, similar to what we have for Sky Lake
Xeon: if package C6 is disabled, adjust C6 exit latency and target residency to
match core C6 values, instead of using the default package C6 values.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
---
drivers/idle/intel_idle.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/idle/intel_idle.c b/drivers/idle/intel_idle.c
index b2688c326522..e385ddf15b32 100644
--- a/drivers/idle/intel_idle.c
+++ b/drivers/idle/intel_idle.c
@@ -1578,6 +1578,8 @@ static void __init skx_idle_state_table_update(void)
*/
static void __init spr_idle_state_table_update(void)
{
+ unsigned long long msr;
+
/* Check if user prefers C1E over C1. */
if (preferred_states_mask & BIT(2)) {
if (preferred_states_mask & BIT(1))
@@ -1591,6 +1593,19 @@ static void __init spr_idle_state_table_update(void)
c1e_promotion_enable();
disable_promotion_to_c1e = false;
}
+
+ /*
+ * By default, the C6 state assumes the worst-case scenario of package
+ * C6. However, if PC6 is disabled, we update the numbers to match
+ * core C6.
+ */
+ rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
+
+ /* Limit value 2 and above allow for PC6. */
+ if ((msr & 0x7) < 2) {
+ spr_cstates[2].exit_latency = 190;
+ spr_cstates[2].target_residency = 600;
+ }
}
static bool __init intel_idle_verify_cstate(unsigned int mwait_hint)
--
2.31.1
next prev parent reply other threads:[~2022-03-02 8:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-02 8:15 [PATCH v1 1/3] intel_idle: add SPR support Artem Bityutskiy
2022-03-02 8:15 ` [PATCH v1 2/3] intel_idle: add 'preferred_cstates' module argument Artem Bityutskiy
2022-03-02 8:16 ` Artem Bityutskiy [this message]
2022-03-04 18:56 ` [PATCH v1 1/3] intel_idle: add SPR support Rafael J. Wysocki
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