linux-kernel - Re: [PATCH 2/4] seq_file: Add seq_cpumask_list(), seq_nodemask

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 16 Oct 2008 15:56:30 -0700
From:	Mike Travis <travis@....com>
To:	Andrew Morton <akpm@...ux-foundation.org>
CC:	Lai Jiangshan <laijs@...fujitsu.com>, adobriyan@...il.com,
	menage@...gle.com, pj@....com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] seq_file: Add seq_cpumask_list(), seq_nodemask_list()

Andrew Morton wrote:
> On Sun, 12 Oct 2008 17:29:25 +0800
> Lai Jiangshan <laijs@...fujitsu.com> wrote:
> 
>> +static inline int seq_cpumask_list(struct seq_file *m, cpumask_t *mask)
>> +{
>> +	return seq_bitmap_list(m, mask->bits, NR_CPUS);
>> +}
> 
> Is it possible to avoid using NR_CPUS?  In some situations it'd be much
> more efficient to use the runtime-determined max possible cpu index.
> 
> But I don't immediately recall how to get at that number. 
> num_possible_cpus() assumes that there are no holes in the CPU
> identifier list.
> 

nr_cpu_ids represents the max index +1 of the possible cpus.  (Usually the
same as num_possible_cpus() except a.) it doesn't need to do the cpus_weight()
op, and b.) *if* (a big if) the cpu indices are sparse, then they wouldn't
be the same values.)

Thanks,
Mike
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/