Mailing List Archive

commit f4efbcf156fb408dcedf1fc88d3be595ec722ad0
Author: Jan Beulich <jbeulich@suse.com>
AuthorDate: Mon Jan 22 13:38:24 2024 +0100
Commit: Andrew Cooper <andrew.cooper3@citrix.com>
CommitDate: Tue Apr 9 16:48:18 2024 +0100

core-parking: use alternative_call()

This way we can arrange for core_parking_{performance,power}()'s ENDBR
to also be zapped.

For the decision to be taken before the 2nd alternative patching pass,
the initcall needs to become a pre-SMP one, though.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
(cherry picked from commit 1bc07ebcac3b1bb2a378732bc0f9a19940e76faf)
---
xen/common/core_parking.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/xen/common/core_parking.c b/xen/common/core_parking.c
index c4f01291c0..a970ffeab8 100644
--- a/xen/common/core_parking.c
+++ b/xen/common/core_parking.c
@@ -30,10 +30,11 @@ static DEFINE_SPINLOCK(accounting_lock);
static uint32_t cur_idle_nums;
static unsigned int core_parking_cpunum[NR_CPUS] = {[0 ... NR_CPUS-1] = -1};

-static const struct cp_policy {
+struct cp_policy {
char name[30];
unsigned int (*next)(unsigned int event);
-} *__read_mostly core_parking_policy;
+};
+static struct cp_policy __ro_after_init core_parking_policy;

static enum core_parking_controller {
POWER_FIRST,
@@ -175,12 +176,13 @@ long cf_check core_parking_helper(void *data)
unsigned int cpu;
int ret = 0;

- if ( !core_parking_policy )
+ if ( !core_parking_policy.next )
return -EINVAL;

while ( cur_idle_nums < idle_nums )
{
- cpu = core_parking_policy->next(CORE_PARKING_INCREMENT);
+ cpu = alternative_call(core_parking_policy.next,
+ CORE_PARKING_INCREMENT);
ret = cpu_down(cpu);
if ( ret )
return ret;
@@ -193,7 +195,8 @@ long cf_check core_parking_helper(void *data)

while ( cur_idle_nums > idle_nums )
{
- cpu = core_parking_policy->next(CORE_PARKING_DECREMENT);
+ cpu = alternative_call(core_parking_policy.next,
+ CORE_PARKING_DECREMENT);
ret = cpu_up(cpu);
if ( ret )
return ret;
@@ -239,12 +242,12 @@ uint32_t get_cur_idle_nums(void)
return cur_idle_nums;
}

-static const struct cp_policy power_first = {
+static const struct cp_policy __initconst_cf_clobber power_first = {
.name = "power",
.next = core_parking_power,
};

-static const struct cp_policy performance_first = {
+static const struct cp_policy __initconst_cf_clobber performance_first = {
.name = "performance",
.next = core_parking_performance,
};
@@ -254,7 +257,7 @@ static int __init register_core_parking_policy(const struct cp_policy *policy)
if ( !policy || !policy->next )
return -EINVAL;

- core_parking_policy = policy;
+ core_parking_policy = *policy;
return 0;
}

@@ -269,4 +272,4 @@ static int __init cf_check core_parking_init(void)

return ret;
}
-__initcall(core_parking_init);
+presmp_initcall(core_parking_init);
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.17