-----Original Message-----
From: Yasufumi Ogawa <yasufu...@gmail.com>
Sent: Wednesday, October 30, 2019 1:42 PM
To: Ananyev, Konstantin <konstantin.anan...@intel.com>; Burakov, Anatoly
<anatoly.bura...@intel.com>; david.march...@redhat.com
Cc: dev@dpdk.org; sta...@dpdk.org; Yasufumi Ogawa <ogawa.yasuf...@lab.ntt.co.jp>
Subject: Re: [dpdk-dev] [PATCH v5 1/1] fbarray: fix duplicated fbarray file in
secondary
On 2019/10/29 21:03, Ananyev, Konstantin wrote:
-----Original Message-----
From: dev <dev-boun...@dpdk.org> On Behalf Of yasufu...@gmail.com
Sent: Monday, October 28, 2019 8:08 AM
To: Burakov, Anatoly <anatoly.bura...@intel.com>; david.march...@redhat.com
Cc: dev@dpdk.org; sta...@dpdk.org; yasufu...@gmail.com; Yasufumi Ogawa
<ogawa.yasuf...@lab.ntt.co.jp>
Subject: [dpdk-dev] [PATCH v5 1/1] fbarray: fix duplicated fbarray file in
secondary
From: Yasufumi Ogawa <ogawa.yasuf...@lab.ntt.co.jp>
In secondary_msl_create_walk(), it creates a file for fbarrays with its
PID for reserving unique name among secondary processes. However, it
does not work if several secondaries run as app containers because each
of containerized secondary has PID 1, and failed to reserve unique name
other than first one. To reserve unique name in each of containers, use
hostname instead of PID only if PID is 1.
Cc: sta...@dpdk.org
Signed-off-by: Yasufumi Ogawa <yasufu...@gmail.com>
---
lib/librte_eal/linux/eal/eal_memalloc.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c
b/lib/librte_eal/linux/eal/eal_memalloc.c
index af6d0d023..699079791 100644
--- a/lib/librte_eal/linux/eal/eal_memalloc.c
+++ b/lib/librte_eal/linux/eal/eal_memalloc.c
@@ -1365,6 +1365,7 @@ secondary_msl_create_walk(const struct rte_memseg_list
*msl,
struct rte_memseg_list *primary_msl, *local_msl;
char name[PATH_MAX];
int msl_idx, ret;
+ char proc_id[HOST_NAME_MAX] = { 0 };
if (msl->external)
return 0;
@@ -1374,8 +1375,18 @@ secondary_msl_create_walk(const struct rte_memseg_list
*msl,
local_msl = &local_memsegs[msl_idx];
/* create distinct fbarrays for each secondary */
- snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%i",
- primary_msl->memseg_arr.name, getpid());
+ /* If run secondary in a container, the name of fbarray file should
+ * not be decided with pid because getpid() always returns 1.
I wonder why is that?
What will prevent user to do something like:
docker run -it --cpuset-cpus=7-8 -v /local/kananye1:/local/kananye1
ubuntu-dpdk-local:latest /bin/bash
And then start dpdk app manually within the container?
Hi Konstantin,
Thank you for your comment.
My concern is running secondary as app container. In current
implementation, the name of fbarray file is decided by using PID and it
must be overlapped with other process because assigning PID is started
from 1 in each of app container. This patch is to fix the issue.
I think it is doable running app from bash for testing, but not
acceptable for a realistic usecase in which user manages several app
containers.
User can have a bash script to start inside container first, that
would do some preparation work (setup env variables, etc.)....
Or some different scenario when user needs/wants to
spawn several processes within container.
I don't know how to avoid to overlap PID from bash script because I
think PIDs on host cannot see from inside of a container. So, I'm not
sure it is possible.
Inside the lib you can't assume that your usage scenario is the
only possible one.
I don't want to modify it for a specific usecase, but just to avoid to
overlap filenames. I think it is better this filename is decided by lib
itself without any of user configuration because user don't need to care
about the file which is used by DPDK internally.
I think solution needs to be generic enough to cover all such cases.
BTW, why we can't always use hostname in fbarray format?
Sorry, I don't know. But I wonder using PID is more assured to get
unique name, but does not work only for secondary app container
accidentally.
Yasufumi
Regards,
Yasufumi
+ * In docker, hostname is assigned as a short form of full container
+ * ID. So use hostname as unique ID among containers instead.
+ */
+ if (getpid() == 1)
+ gethostname(proc_id, HOST_NAME_MAX);
+ else
+ sprintf(proc_id, "%d", (int)getpid());
+
+ snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%s",
+ primary_msl->memseg_arr.name, proc_id);
ret = rte_fbarray_init(&local_msl->memseg_arr, name,
primary_msl->memseg_arr.len,
--
2.17.1
