diff --git a/mm/cma.c b/mm/cma.c index 2906ae5a83ff..a6033e344430 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -348,6 +348,32 @@ err: return ret; } +#ifdef CONFIG_CMA_DEBUG +static void cma_debug_show_areas(struct cma *cma) +{ + unsigned long next_zero_bit, next_set_bit; + unsigned long start = 0; + unsigned int nr_zero, nr_total = 0; + + mutex_lock(&cma->lock); + pr_info("number of available pages: "); + for (;;) { + next_zero_bit = find_next_zero_bit(cma->bitmap, cma->count, start); + if (next_zero_bit >= cma->count) + break; + next_set_bit = find_next_bit(cma->bitmap, cma->count, next_zero_bit); + nr_zero = next_set_bit - next_zero_bit; + pr_cont("%s%u@%lu", nr_total ? "+" : "", nr_zero, next_zero_bit); + nr_total += nr_zero; + start = next_zero_bit + nr_zero; + } + pr_cont("=> %u free of %lu total pages\n", nr_total, cma->count); + mutex_unlock(&cma->lock); +} +#else +static inline void cma_debug_show_areas(struct cma *cma) { } +#endif + /** * cma_alloc() - allocate pages from contiguous area * @cma: Contiguous memory region for which the allocation is performed. @@ -365,7 +391,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, unsigned long start = 0; unsigned long bitmap_maxno, bitmap_no, bitmap_count; struct page *page = NULL; - int ret; + int ret = -ENOMEM; if (!cma || !cma->count) return NULL; @@ -423,6 +449,12 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, trace_cma_alloc(pfn, page, count, align); + if (ret) { + pr_info("%s: alloc failed, req-size: %zu pages, ret: %d\n", + __func__, count, ret); + cma_debug_show_areas(cma); + } + pr_debug("%s(): returned %p\n", __func__, page); return page; }