lkml.org 
[lkml]   [2021]   [Nov]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] x86/smp: Factor out parts of native_smp_prepare_cpus()
From
On 11/11/21 11:15, Peter Zijlstra wrote:
> On Wed, Nov 10, 2021 at 10:52:09PM +0100, Josef Johansson wrote:
>> On 11/3/21 00:36, Boris Ostrovsky wrote:
>>> Commit 66558b730f25 ("sched: Add cluster scheduler level for x86")
>>> introduced cpu_l2c_shared_map mask which is expected to be initialized
>>> by smp_op.smp_prepare_cpus(). That commit only updated
>>> native_smp_prepare_cpus() version but not xen_pv_smp_prepare_cpus().
>>> As result Xen PV guests crash in set_cpu_sibling_map().
>>>
>>> While the new mask can be allocated in xen_pv_smp_prepare_cpus() one can
>>> see that both versions of smp_prepare_cpus ops share a number of common
>>> operations that can be factored out. So do that instead.
>>>
>>> Fixes: 66558b730f25 ("sched: Add cluster scheduler level for x86")
>>> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>>> ---
>>> arch/x86/include/asm/smp.h | 1 +
>>> arch/x86/kernel/smpboot.c | 19 +++++++++++++------
>>> arch/x86/xen/smp_pv.c | 11 ++---------
>>> 3 files changed, 16 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
>>> index 08b0e90623ad..81a0211a372d 100644
>>> --- a/arch/x86/include/asm/smp.h
>>> +++ b/arch/x86/include/asm/smp.h
>>> @@ -126,6 +126,7 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask)
>>>
>>> void cpu_disable_common(void);
>>> void native_smp_prepare_boot_cpu(void);
>>> +void smp_prepare_cpus_common(void);
>>> void native_smp_prepare_cpus(unsigned int max_cpus);
>>> void calculate_max_logical_packages(void);
>>> void native_smp_cpus_done(unsigned int max_cpus);
>>> diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
>>> index 8241927addff..d7429198c22f 100644
>>> --- a/arch/x86/kernel/smpboot.c
>>> +++ b/arch/x86/kernel/smpboot.c
>>> @@ -1350,12 +1350,7 @@ static void __init smp_get_logical_apicid(void)
>>> cpu0_logical_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
>>> }
>>>
>>> -/*
>>> - * Prepare for SMP bootup.
>>> - * @max_cpus: configured maximum number of CPUs, It is a legacy parameter
>>> - * for common interface support.
>>> - */
>>> -void __init native_smp_prepare_cpus(unsigned int max_cpus)
>>> +void __init smp_prepare_cpus_common(void)
>>> {
>>> unsigned int i;
>> Testing out this patch I got a warning that i is unused. Which it is,
>> since for_each_possible_cpu(i) is removed.
> Fixed. Can I add your Tested-by ?
Yes, I tested with tip.

Regards
Josef

\
 
 \ /
  Last update: 2021-11-11 13:40    [W:0.047 / U:0.384 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site