[PATCH] __get_page_state() cpumask cleanup and fix (b40607fc) · Commits · 戴 / test

__get_page_state() has an open-coded for_each_cpu_mask() loop in it. Tidy that up, then notice that the code was buggy: while (cpu < NR_CPUS) { unsigned long *in, *out, off; if (!cpu_isset(cpu, *cpumask)) continue; an obvious infinite loop. I guess we just never call it with a holey cpu mask. Even after my cpumask size-reduction work, this patch increases code size :( Cc: Paul Jackson <pj@sgi.com> Cc: Christoph Lameter <clameter@engr.sgi.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

mm/page_alloc.c

+9 −11

Original line number	Diff line number	Diff line
		@@ -1214,24 +1214,22 @@ DEFINE_PER_CPU(long, nr_pagecache_local) = 0;

		static void __get_page_state(struct page_state ret, int nr, cpumask_t cpumask)
		{
		int cpu = 0;
		unsigned cpu;

		memset(ret, 0, nr * sizeof(unsigned long));
		cpus_and(cpumask, cpumask, cpu_online_map);

		cpu = first_cpu(*cpumask);
		while (cpu < NR_CPUS) {
		unsigned long in, out, off;

		if (!cpu_isset(cpu, *cpumask))
		continue;
		for_each_cpu_mask(cpu, *cpumask) {
		unsigned long *in;
		unsigned long *out;
		unsigned off;
		unsigned next_cpu;

		in = (unsigned long *)&per_cpu(page_states, cpu);

		cpu = next_cpu(cpu, *cpumask);

		if (likely(cpu < NR_CPUS))
		prefetch(&per_cpu(page_states, cpu));
		next_cpu = next_cpu(cpu, *cpumask);
		if (likely(next_cpu < NR_CPUS))
		prefetch(&per_cpu(page_states, next_cpu));

		out = (unsigned long *)ret;
		for (off = 0; off < nr; off++)

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