Merge "percpu: fix synchronization between chunk->map_extend_work and chunk destruction" (9848a9d8) · Commits · e / devices / android_kernel_xiaomi_markw

mm/percpu.c

+36 −21

Original line number	Diff line number	Diff line
		@@ -110,7 +110,7 @@ struct pcpu_chunk {
		int map_used; /* # of map entries used before the sentry */
		int map_alloc; /* # of map entries allocated */
		int map; / allocation map */
		struct work_struct map_extend_work;/* async ->map[] extension */
		struct list_head map_extend_list;/* on pcpu_map_extend_chunks */

		void data; / chunk data */
		int first_free; /* no free below this */
		@@ -164,6 +164,9 @@ static DEFINE_MUTEX(pcpu_alloc_mutex); /* chunk create/destroy, [de]pop, map ext

		static struct list_head pcpu_slot __read_mostly; / chunk list slots */

		/* chunks which need their map areas extended, protected by pcpu_lock */
		static LIST_HEAD(pcpu_map_extend_chunks);

		/*
		* The number of empty populated pages, protected by pcpu_lock. The
		* reserved chunk doesn't contribute to the count.
		@@ -397,13 +400,19 @@ static int pcpu_need_to_extend(struct pcpu_chunk *chunk, bool is_atomic)
		{
		int margin, new_alloc;

		lockdep_assert_held(&pcpu_lock);

		if (is_atomic) {
		margin = 3;

		if (chunk->map_alloc <
		chunk->map_used + PCPU_ATOMIC_MAP_MARGIN_LOW &&
		pcpu_async_enabled)
		schedule_work(&chunk->map_extend_work);
		chunk->map_used + PCPU_ATOMIC_MAP_MARGIN_LOW) {
		if (list_empty(&chunk->map_extend_list)) {
		list_add_tail(&chunk->map_extend_list,
		&pcpu_map_extend_chunks);
		pcpu_schedule_balance_work();
		}
		}
		} else {
		margin = PCPU_ATOMIC_MAP_MARGIN_HIGH;
		}
		@@ -471,20 +480,6 @@ out_unlock:
		return 0;
		}

		static void pcpu_map_extend_workfn(struct work_struct *work)
		{
		struct pcpu_chunk *chunk = container_of(work, struct pcpu_chunk,
		map_extend_work);
		int new_alloc;

		spin_lock_irq(&pcpu_lock);
		new_alloc = pcpu_need_to_extend(chunk, false);
		spin_unlock_irq(&pcpu_lock);

		if (new_alloc)
		pcpu_extend_area_map(chunk, new_alloc);
		}

		/**
		* pcpu_fit_in_area - try to fit the requested allocation in a candidate area
		* @chunk: chunk the candidate area belongs to
		@@ -744,7 +739,7 @@ static struct pcpu_chunk *pcpu_alloc_chunk(void)
		chunk->map_used = 1;

		INIT_LIST_HEAD(&chunk->list);
		INIT_WORK(&chunk->map_extend_work, pcpu_map_extend_workfn);
		INIT_LIST_HEAD(&chunk->map_extend_list);
		chunk->free_size = pcpu_unit_size;
		chunk->contig_hint = pcpu_unit_size;

		@@ -1131,6 +1126,7 @@ static void pcpu_balance_workfn(struct work_struct *work)
		if (chunk == list_first_entry(free_head, struct pcpu_chunk, list))
		continue;

		list_del_init(&chunk->map_extend_list);
		list_move(&chunk->list, &to_free);
		}

		@@ -1148,6 +1144,25 @@ static void pcpu_balance_workfn(struct work_struct *work)
		pcpu_destroy_chunk(chunk);
		}

		/* service chunks which requested async area map extension */
		do {
		int new_alloc = 0;

		spin_lock_irq(&pcpu_lock);

		chunk = list_first_entry_or_null(&pcpu_map_extend_chunks,
		struct pcpu_chunk, map_extend_list);
		if (chunk) {
		list_del_init(&chunk->map_extend_list);
		new_alloc = pcpu_need_to_extend(chunk, false);
		}

		spin_unlock_irq(&pcpu_lock);

		if (new_alloc)
		pcpu_extend_area_map(chunk, new_alloc);
		} while (chunk);

		/*
		* Ensure there are certain number of free populated pages for
		* atomic allocs. Fill up from the most packed so that atomic
		@@ -1648,7 +1663,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
		*/
		schunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0);
		INIT_LIST_HEAD(&schunk->list);
		INIT_WORK(&schunk->map_extend_work, pcpu_map_extend_workfn);
		INIT_LIST_HEAD(&schunk->map_extend_list);
		schunk->base_addr = base_addr;
		schunk->map = smap;
		schunk->map_alloc = ARRAY_SIZE(smap);
		@@ -1678,7 +1693,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
		if (dyn_size) {
		dchunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0);
		INIT_LIST_HEAD(&dchunk->list);
		INIT_WORK(&dchunk->map_extend_work, pcpu_map_extend_workfn);
		INIT_LIST_HEAD(&dchunk->map_extend_list);
		dchunk->base_addr = base_addr;
		dchunk->map = dmap;
		dchunk->map_alloc = ARRAY_SIZE(dmap);