mm: make deferred init's max threads arch-specific

Using padata during deferred init has only been tested on x86, so for now limit it to this architecture. If another arch wants this, it can find the max thread limit that's best for it and override deferred_page_init_max_threads().

Daniel Jordan committed 6 years ago

Commit ecd09651 parent e4443143 files · +23 −5Browse files

Unified · Split

3 files

arch/x86/mm/init_64.c +12 −0
include/linux/memblock.h +3 −0
mm/page_alloc.c +8 −5

arch/x86/mm/init_64.c+12−0

@@ -1265,6 +1265,18 @@ void __init mem_init(void) · 1264 unmodified lines
1265	1265	mem_init_print_info(NULL);
1266	1266	}
1267	1267
	1268	+#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
	1269	+int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask)
	1270	+{
	1271	+ /*
	1272	+ * More CPUs always led to greater speedups on tested systems, up to
	1273	+ * all the nodes' CPUs. Use all since the system is otherwise idle
	1274	+ * now.
	1275	+ */
	1276	+ return max_t(int, cpumask_weight(node_cpumask), 1);
	1277	+}
	1278	+#endif
	1279	+
1268	1280	int kernel_set_to_readonly;
1269	1281
1270	1282	void mark_rodata_ro(void)

include/linux/memblock.h+3−0

@@ -273,6 +273,9 @@ void __next_mem_pfn_range_in_zone(u64 idx, struct zone zone, · 272 unmodified lines
273	273	#define for_each_free_mem_pfn_range_in_zone_from(i, zone, p_start, p_end) \
274	274	for (; i != U64_MAX; \
275	275	__next_mem_pfn_range_in_zone(&i, zone, p_start, p_end))
	276	+
	277	+int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask);
	278	+
276	279	#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
277	280
278	281	/**

mm/page_alloc.c+8−5

@@ -1836,6 +1836,13 @@ deferred_init_memmap_chunk(unsigned long start_pfn, unsigned long end_pfn, · 1835 unmodified lines
1836	1836	}
1837	1837	}
1838	1838
	1839	+/* An arch may override for more concurrency. */
	1840	+__weak int __init
	1841	+deferred_page_init_max_threads(const struct cpumask *node_cpumask)
	1842	+{
	1843	+ return 1;
	1844	+}
	1845	+
1839	1846	/* Initialise remaining memory on a node */
1840	1847	static int __init deferred_init_memmap(void *data)
1841	1848	{
@@ -1884,11 +1891,7 @@ static int __init deferred_init_memmap(void *data) · 42 unmodified lines
1884	1891	first_init_pfn))
1885	1892	goto zone_empty;
1886	1893
1887		− /*
1888		− * More CPUs always led to greater speedups on tested systems, up to
1889		− * all the nodes' CPUs. Use all since the system is otherwise idle now.
1890		− */
1891		− max_threads = max(cpumask_weight(cpumask), 1u);
	1894	+ max_threads = deferred_page_init_max_threads(cpumask);
1892	1895
1893	1896	while (spfn < epfn) {
1894	1897	unsigned long epfn_align = ALIGN(epfn, PAGES_PER_SECTION);