how does it count the number of contiguous physical pages in map_all_hugepages

how does it count the number of contiguous physical pages in map_all_hugepages

[Jack,Xie Jie]

Hi,

I am learning DPDK recently, when I check l2fwd example, I am a little confused, please someone give me a clue.

In function map_all_hugepages called in rte_eal_hugepage_init,
There are lines of source code like below to count the number of contiguous physical pages,
But I check the source code, I just cannot find where is hugepg_tbl[j].physaddr be set before,
how can here check the value of hugepg_tbl[j].physaddr.

/* reserve a virtual area for next contiguous
                            * physical block: count the number of
                            * contiguous physical pages. */
                            for (j = i+1; j < hpi->num_pages[0] ; j++) {
                                     if (hugepg_tbl[j].physaddr !=
                                         hugepg_tbl[j-1].physaddr + hugepage_sz)
                                               break;
                            }


Thanks !
Jack

Re: how does it count the number of contiguous physical pages in map_all_hugepages

[Bruce Richardson]

On Fri, Jan 16, 2015 at 05:32:08AM +0000, Jack,Xie Jie wrote:
> Hi,
> 
> I am learning DPDK recently, when I check l2fwd example, I am a little confused, please someone give me a clue.
> 
> In function map_all_hugepages called in rte_eal_hugepage_init,
> There are lines of source code like below to count the number of contiguous physical pages,
> But I check the source code, I just cannot find where is hugepg_tbl[j].physaddr be set before,
> how can here check the value of hugepg_tbl[j].physaddr.
> 
> /* reserve a virtual area for next contiguous
>                             * physical block: count the number of
>                             * contiguous physical pages. */
>                             for (j = i+1; j < hpi->num_pages[0] ; j++) {
>                                      if (hugepg_tbl[j].physaddr !=
>                                          hugepg_tbl[j-1].physaddr + hugepage_sz)
>                                                break;
>                             }
> 
> 
> Thanks !
> Jack

See function "find_physaddrs" in "eal_memory.c".

Regards,
/Bruce