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@@ -1671,6 +1671,18 @@ static void __init free_area_init_core(struct pglist_data *pgdat,
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if (batch < 1)
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batch = 1;
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+ /*
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+ * Clamp the batch to a 2^n - 1 value. Having a power
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+ * of 2 value was found to be more likely to have
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+ * suboptimal cache aliasing properties in some cases.
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+ *
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+ * For example if 2 tasks are alternately allocating
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+ * batches of pages, one task can end up with a lot
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+ * of pages of one half of the possible page colors
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+ * and the other with pages of the other colors.
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+ */
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+ batch = (1 << fls(batch + batch/2)) - 1;
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+
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for (cpu = 0; cpu < NR_CPUS; cpu++) {
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struct per_cpu_pages *pcp;
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