s390/cpuinfo: simplify locking and skip offline cpus early (281eaa8c) · Commits · 戴 / test

Move the get_online_cpus() and put_online_cpus() to the start and stop operation of the seqfile ops. This way there is no need to lock cpu hotplug again and again for each single cpu. This way we can also skip offline cpus early if we simply use cpumask_next() within the next operation. Signed-off-by:

Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:

Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/processor.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -84,7 +84,6 @@ static int show_cpuinfo(struct seq_file m, void v)
		seq_puts(m, "\n");
		show_cacheinfo(m);
		}
		get_online_cpus();
		if (cpu_online(n)) {
		struct cpuid *id = &per_cpu(cpu_id, n);
		seq_printf(m, "processor %li: "
		@@ -93,23 +92,31 @@ static int show_cpuinfo(struct seq_file m, void v)
		"machine = %04X\n",
		n, id->version, id->ident, id->machine);
		}
		put_online_cpus();
		return 0;
		}

		static inline void c_update(loff_t pos)
		{
		if (*pos)
		pos = cpumask_next(pos - 1, cpu_online_mask);
		return pos < nr_cpu_ids ? (void )*pos + 1 : NULL;
		}

		static void c_start(struct seq_file m, loff_t *pos)
		{
		return pos < nr_cpu_ids ? (void )((unsigned long) *pos + 1) : NULL;
		get_online_cpus();
		return c_update(pos);
		}

		static void c_next(struct seq_file m, void v, loff_t pos)
		{
		++*pos;
		return c_start(m, pos);
		return c_update(pos);
		}

		static void c_stop(struct seq_file m, void v)
		{
		put_online_cpus();
		}

		const struct seq_operations cpuinfo_op = {

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