2023-05-12 21:24:12

by Thomas Gleixner

[permalink] [raw]
Subject: [patch V4 18/37] x86/xen/hvm: Get rid of DEAD_FROZEN handling

From: Thomas Gleixner <[email protected]>

No point in this conditional voodoo. Un-initializing the lock mechanism is
safe to be called unconditionally even if it was already invoked when the
CPU died.

Remove the invocation of xen_smp_intr_free() as that has been already
cleaned up in xen_cpu_dead_hvm().

Signed-off-by: Thomas Gleixner <[email protected]>
Tested-by: Michael Kelley <[email protected]>
---
arch/x86/xen/enlighten_hvm.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -161,13 +161,12 @@ static int xen_cpu_up_prepare_hvm(unsign
int rc = 0;

/*
- * This can happen if CPU was offlined earlier and
- * offlining timed out in common_cpu_die().
+ * If a CPU was offlined earlier and offlining timed out then the
+ * lock mechanism is still initialized. Uninit it unconditionally
+ * as it's safe to call even if already uninited. Interrupts and
+ * timer have already been handled in xen_cpu_dead_hvm().
*/
- if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
- xen_smp_intr_free(cpu);
- xen_uninit_lock_cpu(cpu);
- }
+ xen_uninit_lock_cpu(cpu);

if (cpu_acpi_id(cpu) != U32_MAX)
per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);





Subject: [tip: smp/core] x86/xen/hvm: Get rid of DEAD_FROZEN handling

The following commit has been merged into the smp/core branch of tip:

Commit-ID: ab24eb9abb9c60c45119370731735b79ed79f36c
Gitweb: https://git.kernel.org/tip/ab24eb9abb9c60c45119370731735b79ed79f36c
Author: Thomas Gleixner <[email protected]>
AuthorDate: Fri, 12 May 2023 23:07:25 +02:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Mon, 15 May 2023 13:44:55 +02:00

x86/xen/hvm: Get rid of DEAD_FROZEN handling

No point in this conditional voodoo. Un-initializing the lock mechanism is
safe to be called unconditionally even if it was already invoked when the
CPU died.

Remove the invocation of xen_smp_intr_free() as that has been already
cleaned up in xen_cpu_dead_hvm().

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Michael Kelley <[email protected]>
Tested-by: Oleksandr Natalenko <[email protected]>
Tested-by: Helge Deller <[email protected]> # parisc
Tested-by: Guilherme G. Piccoli <[email protected]> # Steam Deck
Link: https://lore.kernel.org/r/[email protected]
---
arch/x86/xen/enlighten_hvm.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c
index c1cd28e..a6820ca 100644
--- a/arch/x86/xen/enlighten_hvm.c
+++ b/arch/x86/xen/enlighten_hvm.c
@@ -161,13 +161,12 @@ static int xen_cpu_up_prepare_hvm(unsigned int cpu)
int rc = 0;

/*
- * This can happen if CPU was offlined earlier and
- * offlining timed out in common_cpu_die().
+ * If a CPU was offlined earlier and offlining timed out then the
+ * lock mechanism is still initialized. Uninit it unconditionally
+ * as it's safe to call even if already uninited. Interrupts and
+ * timer have already been handled in xen_cpu_dead_hvm().
*/
- if (cpu_report_state(cpu) == CPU_DEAD_FROZEN) {
- xen_smp_intr_free(cpu);
- xen_uninit_lock_cpu(cpu);
- }
+ xen_uninit_lock_cpu(cpu);

if (cpu_acpi_id(cpu) != U32_MAX)
per_cpu(xen_vcpu_id, cpu) = cpu_acpi_id(cpu);