pcpu_get_pages() creates the temp pages array if not already allocated and returns the pointer to it. As the function is called from both [de]population paths and depopulation can only happen after at least one successful population, the param doesn't make any difference - the allocation will always happen on the population path anyway.
Remove @may_alloc from pcpu_get_pages(). Also, add an lockdep assertion pcpu_alloc_mutex instead of vaguely stating that the exclusion is the caller's responsibility. Signed-off-by: Tejun Heo <[email protected]> --- mm/percpu-vm.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c index 47b47bf..d9e0b61 100644 --- a/mm/percpu-vm.c +++ b/mm/percpu-vm.c @@ -22,21 +22,22 @@ static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk, /** * pcpu_get_pages - get temp pages array * @chunk: chunk of interest - * @may_alloc: may allocate the array * * Returns pointer to array of pointers to struct page which can be indexed - * with pcpu_page_idx(). Note that there is only one array and access - * exclusion is the caller's responsibility. + * with pcpu_page_idx(). Note that there is only one array and accesses + * should be serialized by pcpu_alloc_mutex. * * RETURNS: * Pointer to temp pages array on success. */ -static struct page **pcpu_get_pages(struct pcpu_chunk *chunk, bool may_alloc) +static struct page **pcpu_get_pages(struct pcpu_chunk *chunk_alloc) { static struct page **pages; size_t pages_size = pcpu_nr_units * pcpu_unit_pages * sizeof(pages[0]); - if (!pages && may_alloc) + lockdep_assert_held(&pcpu_alloc_mutex); + + if (!pages) pages = pcpu_mem_zalloc(pages_size); return pages; } @@ -287,7 +288,7 @@ static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) /* need to allocate and map pages, this chunk can't be immutable */ WARN_ON(chunk->immutable); - pages = pcpu_get_pages(chunk, true); + pages = pcpu_get_pages(chunk); if (!pages) return -ENOMEM; @@ -358,7 +359,7 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) * successful population attempt so the temp pages array must * be available now. */ - pages = pcpu_get_pages(chunk, false); + pages = pcpu_get_pages(chunk); BUG_ON(!pages); /* unmap and free */ -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
