From: Li Zefan <lizf@cn.fujitsu.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Rusty Russell <rusty@rustcorp.com.au>,
Mike Travis <travis@sgi.com>, Paul Menage <menage@google.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 4/6] cpuset: don't allocate trial cpuset on stack
Date: Mon, 05 Jan 2009 17:13:01 +0800 [thread overview]
Message-ID: <4961CF1D.8090702@cn.fujitsu.com> (raw)
In-Reply-To: <20090104234659.19e62245.akpm@linux-foundation.org>
>> -static int update_cpumask(struct cpuset *cs, const char *buf)
>> +static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
>> + const char *buf)
>> {
>> struct ptr_heap heap;
>> - struct cpuset trialcs;
>> int retval;
>> int is_load_balanced;
>>
>> @@ -891,8 +909,6 @@ static int update_cpumask(struct cpuset *cs, const char *buf)
>> if (cs == &top_cpuset)
>> return -EACCES;
>>
>> - trialcs = *cs;
>
> Yes, we already do.
>
> That thing contains spinlocks and list_heads (at least), which cannot
> be copied in this way.
>
> Seems that we're doing this gross thing because it just so happens that
> we only use the cpus_allowed and mems_allowed fields, and because
and also cpuset->flags.
> several of the called functions require a cpuset*, but only needed a
> cpumask_t.
>
> How perfectly beastly.
>
trial cpuset is used to ease the validation of changes to a cpuset. It
can be get rid of, but I'm afraid that the resulting code will be more
complex and less readable.
next prev parent reply other threads:[~2009-01-05 9:14 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-31 8:34 [PATCH 0/6] cpuset: convert to new cpumask API Li Zefan
2008-12-31 8:35 ` [PATCH 1/6] cpuset: remove on stack cpumask_t in cpuset_sprintf_cpulist() Li Zefan
2008-12-31 8:35 ` [PATCH 2/6] cpuset: remove on stack cpumask_t in cpuset_can_attach() Li Zefan
2008-12-31 8:36 ` [PATCH 3/6] cpuset: convert cpuset_attach() to use cpumask_var_t Li Zefan
2008-12-31 8:36 ` [PATCH 4/6] cpuset: don't allocate trial cpuset on stack Li Zefan
2008-12-31 8:37 ` [PATCH 5/6] cpuset: convert cpuset->cpus_allowed to cpumask_var_t Li Zefan
2008-12-31 8:37 ` [PATCH 6/6] cpuset: remove remaining pointers to cpumask_t Li Zefan
2009-01-05 7:46 ` [PATCH 4/6] cpuset: don't allocate trial cpuset on stack Andrew Morton
2009-01-05 9:13 ` Li Zefan [this message]
2009-01-05 7:38 ` [PATCH 3/6] cpuset: convert cpuset_attach() to use cpumask_var_t Andrew Morton
2009-01-05 8:47 ` Li Zefan
2009-01-05 9:01 ` Andrew Morton
2009-01-05 9:04 ` Li Zefan
2009-01-05 9:14 ` Andrew Morton
2009-01-05 9:21 ` Li Zefan
2009-01-07 2:04 ` Rusty Russell
2009-01-07 16:39 ` Paul Menage
2008-12-31 11:56 ` [PATCH 0/6] cpuset: convert to new cpumask API Mike Travis
2008-12-31 13:26 ` Rusty Russell
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