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SubjectRe: [PATCH 3/3] cma: add functions to get region pages counters
Date
On Fri, Dec 26 2014, "Stefan I. Strogin" <s.strogin@partner.samsung.com> wrote:
> From: Dmitry Safonov <d.safonov@partner.samsung.com>
>
> Here are two functions that provide interface to compute/get used size
> and size of biggest free chunk in cma region.
> Added that information in cmainfo.
>
> Signed-off-by: Dmitry Safonov <d.safonov@partner.samsung.com>

Acked-by: Michal Nazarewicz <mina86@mina86.com>

> ---
> include/linux/cma.h | 2 ++
> mm/cma.c | 34 ++++++++++++++++++++++++++++++++++
> 2 files changed, 36 insertions(+)
>
> diff --git a/include/linux/cma.h b/include/linux/cma.h
> index 9384ba6..855e6f2 100644
> --- a/include/linux/cma.h
> +++ b/include/linux/cma.h
> @@ -18,6 +18,8 @@ struct cma;
> extern unsigned long totalcma_pages;
> extern phys_addr_t cma_get_base(struct cma *cma);
> extern unsigned long cma_get_size(struct cma *cma);
> +extern unsigned long cma_get_used(struct cma *cma);
> +extern unsigned long cma_get_maxchunk(struct cma *cma);
>
> extern int __init cma_declare_contiguous(phys_addr_t base,
> phys_addr_t size, phys_addr_t limit,
> diff --git a/mm/cma.c b/mm/cma.c
> index ffaea26..5e560ed 100644
> --- a/mm/cma.c
> +++ b/mm/cma.c
> @@ -78,6 +78,36 @@ unsigned long cma_get_size(struct cma *cma)
> return cma->count << PAGE_SHIFT;
> }
>
> +unsigned long cma_get_used(struct cma *cma)
> +{
> + unsigned long ret = 0;
> +
> + mutex_lock(&cma->lock);
> + /* pages counter is smaller than sizeof(int) */
> + ret = bitmap_weight(cma->bitmap, (int)cma->count);
> + mutex_unlock(&cma->lock);
> +
> + return ret << (PAGE_SHIFT + cma->order_per_bit);
> +}
> +
> +unsigned long cma_get_maxchunk(struct cma *cma)
> +{
> + unsigned long maxchunk = 0;
> + unsigned long start, end = 0;
> +
> + mutex_lock(&cma->lock);
> + for (;;) {
> + start = find_next_zero_bit(cma->bitmap, cma->count, end);
> + if (start >= cma->count)
> + break;
> + end = find_next_bit(cma->bitmap, cma->count, start);
> + maxchunk = max(end - start, maxchunk);
> + }
> + mutex_unlock(&cma->lock);
> +
> + return maxchunk << (PAGE_SHIFT + cma->order_per_bit);
> +}
> +
> static unsigned long cma_bitmap_aligned_mask(struct cma *cma, int align_order)
> {
> if (align_order <= cma->order_per_bit)
> @@ -591,6 +621,10 @@ static int s_show(struct seq_file *m, void *p)
> struct cma_buffer *cmabuf;
> struct stack_trace trace;
>
> + seq_printf(m, "CMARegion stat: %8lu kB total, %8lu kB used, %8lu kB max contiguous chunk\n\n",
> + cma_get_size(cma) >> 10,
> + cma_get_used(cma) >> 10,
> + cma_get_maxchunk(cma) >> 10);
> mutex_lock(&cma->list_lock);
>
> list_for_each_entry(cmabuf, &cma->buffers_list, list) {
> --
> 2.1.0
>

--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michał “mina86” Nazarewicz (o o)
ooo +--<mpn@google.com>--<xmpp:mina86@jabber.org>--ooO--(_)--Ooo--


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