Re: [PATCH v4 03/12] xen/spinlock: introduce new type for recursive spinlocks

From: Juergen Gross <jgross@suse.com>
To: Julien Grall <julien@xen.org>, xen-devel@lists.xenproject.org
Cc: "Jan Beulich" <jbeulich@suse.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
	"George Dunlap" <george.dunlap@citrix.com>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Paul Durrant" <paul@xen.org>
Subject: Re: [PATCH v4 03/12] xen/spinlock: introduce new type for recursive spinlocks
Date: Tue, 12 Dec 2023 14:04:09 +0100	[thread overview]
Message-ID: <492c7b3e-ee29-4fe6-b13e-f9928721a78b@suse.com> (raw)
In-Reply-To: <ea25863a-f5da-4873-89f2-d75b3abb9ef8@xen.org>

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On 12.12.23 13:57, Julien Grall wrote:
> Hi Juergen,
> 
> On 12/12/2023 09:47, Juergen Gross wrote:
>> diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h
>> index 1cd9120eac..20d15f34dd 100644
>> --- a/xen/include/xen/spinlock.h
>> +++ b/xen/include/xen/spinlock.h
>> @@ -45,7 +45,7 @@ union lock_debug { };
>>       lock profiling on:
>>       Global locks which should be subject to profiling must be declared via
>> -    DEFINE_SPINLOCK.
>> +    DEFINE_[R]SPINLOCK.
>>       For locks in structures further measures are necessary:
>>       - the structure definition must include a profile_head with exactly this
>> @@ -56,7 +56,7 @@ union lock_debug { };
>>       - the single locks which are subject to profiling have to be initialized
>>         via
>> -      spin_lock_init_prof(ptr, lock);
>> +      [r]spin_lock_init_prof(ptr, lock);
>>         with ptr being the main structure pointer and lock the spinlock field
>> @@ -109,12 +109,16 @@ struct lock_profile_qhead {
>>       spinlock_t l = _SPIN_LOCK_UNLOCKED(NULL);                                 \
>>       static struct lock_profile __lock_profile_data_##l = _LOCK_PROFILE(l);    \
>>       _LOCK_PROFILE_PTR(l)
>> +#define DEFINE_RSPINLOCK(l)                                                   \
>> +    rspinlock_t l = _SPIN_LOCK_UNLOCKED(NULL);                                \
>> +    static struct lock_profile __lock_profile_data_##l = _LOCK_PROFILE(l);    \
>> +    _LOCK_PROFILE_PTR(l)
>> -#define spin_lock_init_prof(s, l)                                             \
>> +#define __spin_lock_init_prof(s, l, locktype)                                 \
> 
> If I am not mistaken the double-underscore prefix is a violation in MISRA. So 
> can this be renamed to:
> 
> spin_lock_init_prof__()?

Fine with me.

Note that __lock_profile_data_##l and __lock_profile_##name seem to violate
MISRA, too. Probably a good idea to change them as well? This should probably
be done as a prereq patch then?

> 
> The rest of the code looks fine. I have checked the lock you are modifying in 
> common/drivers and they all are meant to be recursive lock:
> 
> Acked-by: Julien Grall <jgrall@amazon.com>

Thanks,

Juergen

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