Re: [PATCH v3 1/4] mm: cma: introduce gfp flag in cma_alloc instead of no_warn

Suren Baghdasaryan
2021-01-20T21:09:00Z

On Tue, Jan 12, 2021 at 5:21 PM Minchan Kim <minchan@kernel.org> wrote:
>
> The upcoming patch will introduce __GFP_NORETRY semantic
> in alloc_contig_range which is a failfast mode of the API.
> Instead of adding a additional parameter for gfp, replace
> no_warn with gfp flag.
>
> To keep old behaviors, it follows the rule below.
>
> no_warn gfp_flags
>
> false GFP_KERNEL
> true GFP_KERNEL|__GFP_NOWARN
> gfp & __GFP_NOWARN GFP_KERNEL | (gfp & __GFP_NOWARN)
>
> Signed-off-by: Minchan Kim <minchan@kernel.org>

Reviewed-by: Suren Baghdasaryan <surenb@google.com>

> ---
> drivers/dma-buf/heaps/cma_heap.c | 2 +-
> drivers/s390/char/vmcp.c | 2 +-
> include/linux/cma.h | 2 +-
> kernel/dma/contiguous.c | 3 ++-
> mm/cma.c | 12 ++++++------
> mm/cma_debug.c | 2 +-
> mm/hugetlb.c | 6 ++++--
> mm/secretmem.c | 3 ++-
> 8 files changed, 18 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
> index 364fc2f3e499..0afc1907887a 100644
> --- a/drivers/dma-buf/heaps/cma_heap.c
> +++ b/drivers/dma-buf/heaps/cma_heap.c
> @@ -298,7 +298,7 @@ static int cma_heap_allocate(struct dma_heap *heap,
> if (align > CONFIG_CMA_ALIGNMENT)
> align = CONFIG_CMA_ALIGNMENT;
>
> - cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false);
> + cma_pages = cma_alloc(cma_heap->cma, pagecount, align, GFP_KERNEL);
> if (!cma_pages)
> goto free_buffer;
>
> diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c
> index 9e066281e2d0..78f9adf56456 100644
> --- a/drivers/s390/char/vmcp.c
> +++ b/drivers/s390/char/vmcp.c
> @@ -70,7 +70,7 @@ static void vmcp_response_alloc(struct vmcp_session *session)
> * anymore the system won't work anyway.
> */
> if (order > 2)
> - page = cma_alloc(vmcp_cma, nr_pages, 0, false);
> + page = cma_alloc(vmcp_cma, nr_pages, 0, GFP_KERNEL);
> if (page) {
> session->response = (char *)page_to_phys(page);
> session->cma_alloc = 1;
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 217999c8a762..d6c02d08ddbc 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -45,7 +45,7 @@ extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size,
> const char *name,
> struct cma **res_cma);
> extern struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> - bool no_warn);
> + gfp_t gfp_mask);
> extern bool cma_release(struct cma *cma, const struct page *pages, unsigned int count);
>
> extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void *data);
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 3d63d91cba5c..552ed531c018 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -260,7 +260,8 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
> if (align > CONFIG_CMA_ALIGNMENT)
> align = CONFIG_CMA_ALIGNMENT;
>
> - return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
> + return cma_alloc(dev_get_cma_area(dev), count, align, GFP_KERNEL |
> + (no_warn ? __GFP_NOWARN : 0));
> }
>
> /**
> diff --git a/mm/cma.c b/mm/cma.c
> index 0ba69cd16aeb..35053b82aedc 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -419,13 +419,13 @@ static inline void cma_debug_show_areas(struct cma *cma) { }
> * @cma: Contiguous memory region for which the allocation is performed.
> * @count: Requested number of pages.
> * @align: Requested alignment of pages (in PAGE_SIZE order).
> - * @no_warn: Avoid printing message about failed allocation
> + * @gfp_mask: GFP mask to use during during the cma allocation.
> *
> * This function allocates part of contiguous memory on specific
> * contiguous memory area.
> */
> struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> - bool no_warn)
> + gfp_t gfp_mask)
> {
> unsigned long mask, offset;
> unsigned long pfn = -1;
> @@ -438,8 +438,8 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> if (!cma || !cma->count || !cma->bitmap)
> return NULL;
>
> - pr_debug("%s(cma %p, count %zu, align %d)\n", __func__, (void *)cma,
> - count, align);
> + pr_debug("%s(cma %p, count %zu, align %d gfp_mask 0x%x)\n", __func__,
> + (void *)cma, count, align, gfp_mask);
>
> if (!count)
> return NULL;
> @@ -471,7 +471,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
>
> pfn = cma->base_pfn + (bitmap_no << cma->order_per_bit);
> ret = alloc_contig_range(pfn, pfn + count, MIGRATE_CMA,
> - GFP_KERNEL | (no_warn ? __GFP_NOWARN : 0));
> + gfp_mask);
>
> if (ret == 0) {
> page = pfn_to_page(pfn);
> @@ -500,7 +500,7 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align,
> page_kasan_tag_reset(page + i);
> }
>
> - if (ret && !no_warn) {
> + if (ret && !(gfp_mask & __GFP_NOWARN)) {
> pr_err("%s: alloc failed, req-size: %zu pages, ret: %d\n",
> __func__, count, ret);
> cma_debug_show_areas(cma);
> diff --git a/mm/cma_debug.c b/mm/cma_debug.c
> index d5bf8aa34fdc..00170c41cf81 100644
> --- a/mm/cma_debug.c
> +++ b/mm/cma_debug.c
> @@ -137,7 +137,7 @@ static int cma_alloc_mem(struct cma *cma, int count)
> if (!mem)
> return -ENOMEM;
>
> - p = cma_alloc(cma, count, 0, false);
> + p = cma_alloc(cma, count, 0, GFP_KERNEL);
> if (!p) {
> kfree(mem);
> return -ENOMEM;
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 737b2dce19e6..695af33aa66c 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -1266,7 +1266,8 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
>
> if (hugetlb_cma[nid]) {
> page = cma_alloc(hugetlb_cma[nid], nr_pages,
> - huge_page_order(h), true);
> + huge_page_order(h),
> + GFP_KERNEL | __GFP_NOWARN);
> if (page)
> return page;
> }
> @@ -1277,7 +1278,8 @@ static struct page *alloc_gigantic_page(struct hstate *h, gfp_t gfp_mask,
> continue;
>
> page = cma_alloc(hugetlb_cma[node], nr_pages,
> - huge_page_order(h), true);
> + huge_page_order(h),
> + GFP_KERNEL | __GFP_NOWARN);
> if (page)
> return page;
> }
> diff --git a/mm/secretmem.c b/mm/secretmem.c
> index b8a32954ac68..585d55b9f9d8 100644
> --- a/mm/secretmem.c
> +++ b/mm/secretmem.c
> @@ -86,7 +86,8 @@ static int secretmem_pool_increase(struct secretmem_ctx *ctx, gfp_t gfp)
> struct page *page;
> int err;
>
> - page = cma_alloc(secretmem_cma, nr_pages, PMD_SIZE, gfp & __GFP_NOWARN);
> + page = cma_alloc(secretmem_cma, nr_pages, PMD_SIZE,
> + GFP_KERNEL | (gfp & __GFP_NOWARN));
> if (!page)
> return -ENOMEM;
>
> --
> 2.30.0.284.gd98b1dd5eaa7-goog
>