[PATCH v4 03/10] cpu/SMT: Move smt/control simple exit cases earlier
STALE909d
LANDED
From: Laurent Dufour <hidden>
Date: 2023-07-05 14:52:34
Also in:
linux-arch, lkml
Subsystem:
cpu hotplug, the rest · Maintainers:
Thomas Gleixner, Peter Zijlstra, Linus Torvalds
Revision v4 of 4 in this series; landed in mainline as c53361ce7d87 on 2023-07-28.
Revisions (4)
- v1 [diff vs current]
- v2 [diff vs current]
- v3 [diff vs current]
- v4 current
From: Michael Ellerman <mpe@ellerman.id.au> Move the simple exit cases, ie. which don't depend on the value written, earlier in the function. That makes it clearer that regardless of the input those states can not be transitioned out of. That does have a user-visible effect, in that the error returned will now always be EPERM/ENODEV for those states, regardless of the value written. Previously writing an invalid value would return EINVAL even when in those states. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- kernel/cpu.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/cpu.c b/kernel/cpu.c
index e02204c4675a..b6fe170c93e9 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c@@ -2841,6 +2841,12 @@ __store_smt_control(struct device *dev, struct device_attribute *attr, { int ctrlval, ret; + if (cpu_smt_control == CPU_SMT_FORCE_DISABLED) + return -EPERM; + + if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED) + return -ENODEV; + if (sysfs_streq(buf, "on")) ctrlval = CPU_SMT_ENABLED; else if (sysfs_streq(buf, "off"))
@@ -2850,12 +2856,6 @@ __store_smt_control(struct device *dev, struct device_attribute *attr, else return -EINVAL; - if (cpu_smt_control == CPU_SMT_FORCE_DISABLED) - return -EPERM; - - if (cpu_smt_control == CPU_SMT_NOT_SUPPORTED) - return -ENODEV; - ret = lock_device_hotplug_sysfs(); if (ret) return ret;
--
2.41.0