[dpdk-dev] =?gb18030?b?u9i4tKO6ICBBYm91dCB0aGUgc2hhcmVkIGZsb2Nr?= =?gb18030?q?_for_hugepage_files?=

[=?gb18030?B?sNezpMP0?= <912873551@qq.com>]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="gb18030", Size: 1900 bytes --]

Hi Jim,


Thank you for reply, i understand it, but i still have two doubts.


1) if i have > 1 DPDK application on a machine, i can use the parameter "--file-prefix" to distinguish, it can work even if have not flock.
2) If I understand correctly, in the "map_all_hugepages()", after making the shared flock, close(fd), that is to free the flock. Then, in the "clear_hugedir()", it equal to have not flock ?


------------------ ԭʼÓʼþ ------------------
·¢¼þÈË: "Jim Thompson";<jim@netgate.com>;
·¢ËÍʱ¼ä: 2017Äê9ÔÂ12ÈÕ(ÐÇÆÚ¶þ) ÖÐÎç11:10
ÊÕ¼þÈË: "°×³¤Ãô"<912873551@qq.com>; 
³­ËÍ: "dev"<dev@dpdk.org>; 
Ö÷Ìâ: Re: [dpdk-dev] About the shared flock for hugepage files




Bakari,


This is so you can have > 1 DPDK application on a machine and they won't use each other's hugepages. 


See, for example the comments in clear_hugedir()


http://dpdk.org/browse/dpdk/tree/lib/librte_eal/linuxapp/eal/eal_hugepage_info.c#n198


Jim

On Sep 11, 2017, at 9:16 PM, °×³¤Ãô <912873551@qq.com> wrote:


Hi, everyone,


    I'm a developer from china, now i have a problem is about the shared flock for hugepage files in the function of "map_all_hugepages()".


as follows:
---------------------------------------------------------------------------------------------------
/* set shared flock on the file. */


if (flock(fd, LOCK_SH | LOCK_NB) == -1) {


        RTE_LOG(DEBUG, EAL, "%s(): Locking file failed:%s \n", __func__, strerror(errno));


        close(fd);


        return i;


}


close(fd);

--------------------------------------------------------------------------------------------------
there, it gives a shared flock to each hugepage file in /mnt/huge, and close it right away. 


it makes me puzzled. Why? What doing that is for? 


I'm looking forward to your reply, thank you very much.


best regards,
Bakari.