From: Joao Martins <joao.m.martins@oracle.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
Keir Fraser <keir@xen.org>,
xen-devel@lists.xen.org
Subject: Re: [PATCH v2 5/6] x86/time: refactor read_platform_stime()
Date: Tue, 5 Apr 2016 16:22:58 +0100 [thread overview]
Message-ID: <5703D852.8040909@oracle.com> (raw)
In-Reply-To: <5703C31302000078000E326A@prv-mh.provo.novell.com>
On 04/05/2016 12:52 PM, Jan Beulich wrote:
>>>> On 29.03.16 at 15:44, <joao.m.martins@oracle.com> wrote:
>> -static s_time_t read_platform_stime(void)
>> +static s_time_t read_platform_stime(u64 *stamp)
>> {
>> - u64 count;
>> + u64 plt_stamp_counter, count;
>
> "stamp" and "counter" seem kind of redundant.
>
A bit, perhaps you prefer the latter? There was a variable named "count", so I
named "stamp" for clearer distinction between the variables and the output arg.
>> s_time_t stime;
>>
>> ASSERT(!local_irq_is_enabled());
>>
>> spin_lock(&platform_timer_lock);
>> - count = plt_stamp64 + ((plt_src.read_counter() - plt_stamp) & plt_mask);
>> + plt_stamp_counter = plt_src.read_counter();
>> + count = plt_stamp64 + ((plt_stamp_counter - plt_stamp) & plt_mask);
>> stime = __read_platform_stime(count);
>> + if ( stamp )
>> + *stamp = plt_stamp_counter;
>> spin_unlock(&platform_timer_lock);
>
> What reason is there to do that conditional write inside the locked
> region?
>
None, I should move this conditional write out of this region.
Joao
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next prev parent reply other threads:[~2016-04-05 15:22 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-29 13:44 [PATCH v2 0/6] x86/time: PVCLOCK_TSC_STABLE_BIT support Joao Martins
2016-03-29 13:44 ` [PATCH v2 1/6] public/xen.h: add flags field to vcpu_time_info Joao Martins
2016-03-30 15:49 ` Ian Jackson
2016-03-30 16:33 ` Joao Martins
2016-03-31 7:09 ` Jan Beulich
2016-03-31 7:13 ` Jan Beulich
2016-03-31 11:04 ` Joao Martins
2016-04-05 10:16 ` Jan Beulich
2016-04-05 10:59 ` Joao Martins
2016-03-29 13:44 ` [PATCH v2 2/6] x86/time: refactor init_platform_time() Joao Martins
2016-04-01 16:10 ` Konrad Rzeszutek Wilk
2016-04-01 18:26 ` Joao Martins
2016-04-05 10:09 ` Jan Beulich
2016-04-05 10:55 ` Joao Martins
2016-04-05 11:16 ` Jan Beulich
2016-03-29 13:44 ` [PATCH v2 3/6] x86/time: implement tsc as clocksource Joao Martins
2016-03-29 17:39 ` Konrad Rzeszutek Wilk
2016-03-29 17:52 ` Joao Martins
2016-04-01 16:43 ` Konrad Rzeszutek Wilk
2016-04-01 18:38 ` Joao Martins
2016-04-01 18:45 ` Konrad Rzeszutek Wilk
2016-04-03 18:47 ` Joao Martins
2016-04-05 10:43 ` Jan Beulich
2016-04-05 14:56 ` Joao Martins
2016-04-05 15:12 ` Jan Beulich
2016-04-05 17:07 ` Joao Martins
2016-03-29 13:44 ` [PATCH v2 4/6] x86/time: streamline platform time init on plt_init() Joao Martins
2016-04-05 11:46 ` Jan Beulich
2016-04-05 15:12 ` Joao Martins
2016-04-05 15:22 ` Jan Beulich
2016-04-05 17:17 ` Joao Martins
2016-03-29 13:44 ` [PATCH v2 5/6] x86/time: refactor read_platform_stime() Joao Martins
2016-04-01 18:32 ` Konrad Rzeszutek Wilk
2016-04-05 11:52 ` Jan Beulich
2016-04-05 15:22 ` Joao Martins [this message]
2016-04-05 15:26 ` Jan Beulich
2016-04-05 17:08 ` Joao Martins
2016-03-29 13:44 ` [PATCH v2 6/6] x86/time: implement PVCLOCK_TSC_STABLE_BIT Joao Martins
2016-04-05 12:22 ` Jan Beulich
2016-04-05 21:34 ` Joao Martins
2016-04-07 15:58 ` Jan Beulich
2016-04-07 21:17 ` Joao Martins
2016-04-07 21:32 ` Jan Beulich
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