percpu: setup_first_chunk enforce dynamic region must exist (fb29a2cc) · Commits · 戴 / test

The first chunk is handled as a special case as it is composed of the static, reserved, and dynamic regions. The code handles each case individually. The next several patches will merge these code paths and lay the foundation for the bitmap allocator. This patch modifies logic to enforce that a dynamic region exists and changes the area map to account for that. This brings the logic closer to the dynamic chunk's init logic. Signed-off-by:

Dennis Zhou <dennisszhou@gmail.com> Reviewed-by:

Josef Bacik <jbacik@fb.com> Signed-off-by:

Tejun Heo <tj@kernel.org>

mm/percpu.c

+4 −5

Original line number	Diff line number	Diff line
		@@ -1598,6 +1598,7 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
		PCPU_SETUP_BUG_ON(offset_in_page(ai->unit_size));
		PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
		PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE);
		PCPU_SETUP_BUG_ON(!ai->dyn_size);
		PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);

		/* process group information and build config tables accordingly */
		@@ -1700,14 +1701,12 @@ int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
		schunk->free_size = dyn_size;
		dyn_size = 0; /* dynamic area covered */
		}
		schunk->contig_hint = schunk->free_size;

		schunk->contig_hint = schunk->free_size;
		schunk->map[0] = 1;
		schunk->map[1] = ai->static_size;
		schunk->map_used = 1;
		if (schunk->free_size)
		schunk->map[++schunk->map_used] = ai->static_size + schunk->free_size;
		schunk->map[schunk->map_used] \|= 1;
		schunk->map[2] = (ai->static_size + schunk->free_size) \| 1;
		schunk->map_used = 2;
		schunk->has_reserved = true;

		/* init dynamic chunk if necessary */

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