Re: [PATCH v3 11/12] mm/gup_benchmark: support pin_user_pages() and related calls

John Hubbard
2020-02-03T21:17:47Z

On 2/3/20 5:58 AM, Kirill A. Shutemov wrote:
...
>> @@ -19,6 +21,48 @@ struct gup_benchmark {
>> __u64 expansion[10]; /* For future use */
>> };
>>
>> +static void put_back_pages(unsigned int cmd, struct page **pages,
>> + unsigned long nr_pages)
>> +{
>> + int i;
>> +
>> + switch (cmd) {
>> + case GUP_FAST_BENCHMARK:
>> + case GUP_LONGTERM_BENCHMARK:
>> + case GUP_BENCHMARK:
>> + for (i = 0; i < nr_pages; i++)
>
> 'i' is 'int' and 'nr_pages' is 'unsigned long'.
> There's space for trouble :P
>

Yes, I've changed it to "unsigned int", thanks.

>> + put_page(pages[i]);
>> + break;
>> +
>> + case PIN_FAST_BENCHMARK:
>> + case PIN_BENCHMARK:
>> + unpin_user_pages(pages, nr_pages);
>> + break;
>> + }
>> +}
>> +
>> +static void verify_dma_pinned(unsigned int cmd, struct page **pages,
>> + unsigned long nr_pages)
>> +{
>> + int i;
>> + struct page *page;
>> +
>> + switch (cmd) {
>> + case PIN_FAST_BENCHMARK:
>> + case PIN_BENCHMARK:
>> + for (i = 0; i < nr_pages; i++) {
>
> Ditto.
>

Fixed here also.

>> + page = pages[i];
>> + if (WARN(!page_maybe_dma_pinned(page),
>> + "pages[%d] is NOT dma-pinned\n", i)) {

...and changed to "pages[%u]", to match.

thanks,
--
John Hubbard
NVIDIA

>> +
>> + dump_page(page, "gup_benchmark failure");
>> + break;
>> + }
>> + }
>> + break;
>> + }
>> +}
>> +
>> static int __gup_benchmark_ioctl(unsigned int cmd,
>> struct gup_benchmark *gup)
>> {
>