On 06/25/2013 06:47 PM, Jan Stancek wrote:
>
> ----- Original Message -----
>> From: "DAN LI" <[email protected]>
>> To: "LTP list" <[email protected]>
>> Cc: "Jan Stancek" <[email protected]>, [email protected], "Caspar Zhang"
>> <[email protected]>
>> Sent: Tuesday, 25 June, 2013 11:13:27 AM
>> Subject: [LTP] [PATCH v2] mmap/mmap12.c: new case to test MAP_POPULATE of
>> mmap
>>
>>
>> Create test case for MAP_POPULATE of mmap.
>>
>> Verify the following statement
>> "For a file mapping,this causes read-ahead on the file.
>> Later accesses to the mapping will not be blocked by page faults."
>> by mmap-ing a file and check if all pages are present.
>>
>>
>> Signed-off-by: DAN LI <[email protected]>
>> ---
>> runtest/syscalls | 1 +
>> testcases/kernel/syscalls/mmap/mmap12.c | 194
>> ++++++++++++++++++++++++++++++++
>> 2 files changed, 195 insertions(+)
>> create mode 100644 testcases/kernel/syscalls/mmap/mmap12.c
>
> <snip>
>
>> +
>> +static int page_check(void)
>> +{
>> + int pid;
>> + int ret;
>> + int pm;
>> + int num_pages;
>> + long index;
>> + off_t offset;
>> + size_t page_sz;
>> + char maps_dev[PATHLEN];
>> + char pagemap_dev[PATHLEN];
>> + char line[LINELEN];
>> + FILE *maps;
>> + unsigned long vm_start;
>> + unsigned long vm_end;
>> + unsigned long long pagemap;
>> +
>> + page_sz = getpagesize();
>> +
>> + pid = getpid();
>> + sprintf(maps_dev, "/proc/%d/maps", pid);
>> + sprintf(pagemap_dev, "/proc/%d/pagemap", pid);
>> +
>> + maps = fopen(maps_dev, "r");
>> + if (maps == NULL)
>> + tst_brkm(TFAIL | TERRNO, NULL, "Open dev maps failed");
>> +
>> + while (fgets(line, LINELEN, maps) != NULL)
>> + if (strstr(line, TEMPFILE) != NULL)
>> + break;
>> +
>> + ret = sscanf(line, "%lX-%lX", &vm_start, &vm_end);
>
> Why parsing these 2 from maps? Size is defined by you, and you get vm_start
> from mmap().
Just a force of inertia following pagemap document.
>
>> + if (ret != 2)
>> + tst_brkm(TFAIL | TERRNO, NULL, "Get address space failed");
>> +
>> + num_pages = (vm_end - vm_start) / page_sz;
>> + index = (vm_start / page_sz) * sizeof(unsigned long long);
>
> C99 says long long is _at least_ 64 bits wide. If it's larger than 64, formula
> above would break. How about using type, that's exactly 64 bit (uint64_t)?
Get it.
>
>> +
>> + pm = open(pagemap_dev, O_RDONLY);
>> + if (pm == -1)
>> + tst_brkm(TFAIL | TERRNO, NULL, "Open dev pagemap failed");
>> +
>> + offset = lseek(pm, index, SEEK_SET);
>> + if (offset != index)
>> + tst_brkm(TFAIL | TERRNO, NULL, "Reposition offset failed");
>> +
>> + while (num_pages > 0) {
>> + ret = read(pm, &pagemap, sizeof(unsigned long long));
>> + if (ret < 0)
>> + tst_brkm(TFAIL | TERRNO, NULL, "Read pagemap failed");
>> + /*
>> + * Check if the page is present.
>> + */
>> + if (!(pagemap & (1ULL<<63))) {
>> + close(pm);
>> + fclose(maps);
>> + return 1;
>> + }
>> + num_pages--;
>> + }
>> +
>> + close(pm);
>> + fclose(maps);
>> +
>> + return 0;
>> +}
>> +
>> +static void setup(void)
>> +{
>> + tst_sig(FORK, DEF_HANDLER, cleanup);
>> +
>> + if ((tst_kvercmp(2, 6, 25)) < 0)
>> + tst_brkm(TCONF, NULL,
>> + "This test can only run on kernels that are 2.6.23 and "
>
> Message says 2.6.23, but check is for 2.6.25.
Wow...
All of the above will be fixed in coming V3.
Thank you for reviewing.
Regards,
DAN LI
>
>> + "higher");
>> +
>> + TEST_PAUSE;
>> +
>> + tst_tmpdir();
>> +
>> + fildes = open(TEMPFILE, O_RDWR | O_CREAT, 0766);
>> + if (fildes < 0)
>> + tst_brkm(TFAIL, cleanup, "opening %s failed", TEMPFILE);
>> +
>> + if (ftruncate(fildes, MMAPSIZE) < 0)
>> + tst_brkm(TFAIL | TERRNO, cleanup, "ftruncate file failed");
>> +
>> +}
>> +
>> +static void cleanup(void)
>> +{
>> + close(fildes);
>> + TEST_CLEANUP;
>> + tst_rmdir();
>> +}
>> --
>> 1.8.1
>>
>
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