Without passing opinion on the behaviour of this function, it is deceptive to
read (I've twice now mistaken it for resetting boot_cpu_data), and
inefficient.
Instead of having a 256 byte object on the stack and a double copy, copy
boot_cpu_data directly, then reset parts of cpu_data[cpu] in place. Leave
some comments behind explaining what's happening.
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <jbeulich@suse.com>
CC: Roger Pau Monné <roger@xenproject.org>
CC: Teddy Astie <teddy.astie@vates.tech>
Pulled out of separate series.
---
xen/arch/x86/smpboot.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index 84e9e4beed60..cede2b886f33 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -94,12 +94,14 @@ void *stack_base[NR_CPUS];
void initialize_cpu_data(unsigned int cpu)
{
- struct cpuinfo_x86 c = boot_cpu_data;
+ struct cpuinfo_x86 *c = &cpu_data[cpu];
- /* Must not partially clear the BSP's collected data. */
+ /* First, inherit from boot_cpu_data */
+ *c = boot_cpu_data;
+
+ /* Second, reset most of it, except if we're the BSP at early boot. */
if ( cpu || system_state > SYS_STATE_smp_boot )
- reset_cpuinfo(&c, true);
- cpu_data[cpu] = c;
+ reset_cpuinfo(c, true);
}
static bool smp_store_cpu_info(unsigned int id)
--
2.39.5