From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
David Marchand <david.marchand@redhat.com>,
Yasufumi Ogawa <yasufum.o@gmail.com>
Cc: dev <dev@dpdk.org>, dpdk stable <stable@dpdk.org>,
Yasufumi Ogawa <ogawa.yasufumi@lab.ntt.co.jp>
Subject: Re: [dpdk-stable] [PATCH v6 1/1] fbarray: fix duplicated fbarray file in secondary
Date: Wed, 6 Nov 2019 10:37:42 +0000 [thread overview]
Message-ID: <9c3fba36-9cb2-76ad-198f-c11a63f01a9a@intel.com> (raw)
In-Reply-To: <2601191342CEEE43887BDE71AB97725801A8C800B7@IRSMSX104.ger.corp.intel.com>
On 05-Nov-19 11:41 AM, Ananyev, Konstantin wrote:
>
>
>> -----Original Message-----
>> From: Burakov, Anatoly <anatoly.burakov@intel.com>
>> Sent: Tuesday, November 5, 2019 11:31 AM
>> To: David Marchand <david.marchand@redhat.com>; Yasufumi Ogawa <yasufum.o@gmail.com>
>> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; dev <dev@dpdk.org>; dpdk stable <stable@dpdk.org>; Yasufumi Ogawa
>> <ogawa.yasufumi@lab.ntt.co.jp>
>> Subject: Re: [PATCH v6 1/1] fbarray: fix duplicated fbarray file in secondary
>>
>> On 05-Nov-19 10:13 AM, David Marchand wrote:
>>> Hello Anatoly, Yasufumi,
>>>
>>> On Mon, Nov 4, 2019 at 11:20 AM Burakov, Anatoly
>>> <anatoly.burakov@intel.com> wrote:
>>>>
>>>> On 01-Nov-19 9:04 AM, yasufum.o@gmail.com wrote:
>>>>> From: Yasufumi Ogawa <ogawa.yasufumi@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 in addition to PID.
>>>>>
>>>>> Cc: stable@dpdk.org
>>>
>>> We can't backport this as is, see below.
>>>
>>>
>>>>>
>>>>> Signed-off-by: Yasufumi Ogawa <yasufum.o@gmail.com>
>>>>> ---
>>>>> lib/librte_eal/common/include/rte_fbarray.h | 2 +-
>>>>> lib/librte_eal/linux/eal/eal_memalloc.c | 11 ++++++++---
>>>>> 2 files changed, 9 insertions(+), 4 deletions(-)
>>>>>
>>>>> diff --git a/lib/librte_eal/common/include/rte_fbarray.h b/lib/librte_eal/common/include/rte_fbarray.h
>>>>> index 6dccdbec9..5c2815093 100644
>>>>> --- a/lib/librte_eal/common/include/rte_fbarray.h
>>>>> +++ b/lib/librte_eal/common/include/rte_fbarray.h
>>>>> @@ -39,7 +39,7 @@ extern "C" {
>>>>> #include <rte_compat.h>
>>>>> #include <rte_rwlock.h>
>>>>>
>>>>> -#define RTE_FBARRAY_NAME_LEN 64
>>>>> +#define RTE_FBARRAY_NAME_LEN NAME_MAX
>>>
>>> The change on RTE_FBARRAY_NAME_LEN breaks the ABI, so we cannot
>>> backport this as is.
>>> For 19.11, we can allow this breakage, but we need an update of the
>>> release notes.
>>>
>>> Besides, what is the impact in terms of memory consumption?
>>>
>>>
>>>>>
>>>>> struct rte_fbarray {
>>>>> char name[RTE_FBARRAY_NAME_LEN]; /**< name associated with an array */
>>>>> diff --git a/lib/librte_eal/linux/eal/eal_memalloc.c b/lib/librte_eal/linux/eal/eal_memalloc.c
>>>>> index af6d0d023..24f0275c9 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 hostname[HOST_NAME_MAX] = { 0 };
>>>>>
>>>>> if (msl->external)
>>>>> return 0;
>>>>> @@ -1373,9 +1374,13 @@ secondary_msl_create_walk(const struct rte_memseg_list *msl,
>>>>> primary_msl = &mcfg->memsegs[msl_idx];
>>>>> 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());
>>>>> + /* Create distinct fbarrays for each secondary by using PID and
>>>>> + * hostname. The reason why using hostname is because PID could be
>>>>> + * duplicated among secondaries if it is launched in a container.
>>>>> + */
>>>>> + gethostname(hostname, HOST_NAME_MAX);
>>>
>>> Personal preference, s/HOST_NAME_MAX/sizeof(hostname)/.
>>>
>>>
>>> hostname[] is HOST_NAME_MAX bytes long.
>>> In the worst case, we can get a non NULL terminated hostname string.
>>> "
>>> gethostname() returns the null-terminated hostname in the
>>> character array name, which has a length of len bytes. If the
>>> null-terminated hostname is too large to fit, then the name is
>>> truncated, and
>>> no error is returned (but see NOTES below). POSIX.1-2001 says
>>> that if such truncation occurs, then it is unspecified whether the
>>> returned buffer includes a terminating null byte.
>>> ...
>>> NOTES
>>> SUSv2 guarantees that "Host names are limited to 255 bytes".
>>> POSIX.1-2001 guarantees that "Host names (not including the
>>> terminating null byte) are limited to HOST_NAME_MAX bytes". On
>>> Linux,
>>> HOST_NAME_MAX is defined with the value 64, which has been the
>>> limit since Linux 1.0 (earlier kernels imposed a limit of 8 bytes).
>>> "
>>>
>>> How about making hostname[] HOST_NAME_MAX+1 bytes long?
>>>
>>>>> + snprintf(name, RTE_FBARRAY_NAME_LEN, "%s_%s_%d",
>>>>> + primary_msl->memseg_arr.name, hostname, (int)getpid());
>>>>>
>>>>> ret = rte_fbarray_init(&local_msl->memseg_arr, name,
>>>>> primary_msl->memseg_arr.len,
>>>>>
>>>>
>>>> I think the order should be reversed. Both containers and non-containers
>>>> can have their hostname set, and RTE_FBARRAY_NAME_LEN is of fairly
>>>> limited length, so if the hostname is long enough, the PID never gets
>>>> into the name string, resulting in duplicates. It is better have pid first.
>>>
>>> Anatoly,
>>>
>>> On the principle, it seems better, yes.
>>> Just the comment on RTE_FBARRAY_NAME_LEN indicates that you missed the
>>> change at the top of the patch.
>>> What do you think of this change?
>>>
>>
>> Yes, i did miss that, apologies.
>>
>> I don't have a strong opinion on this change, however the above comment
>> would still be true if we make fbarray size to be hostname_max + 1 - we
>> still potentially get no space for a pid. So if we're going to have pid
>> in there as well, it should be hostname_max + pid_max (5 digits?) +
>> whatever underscores we have + null terminator, to ensure it fits under
>> any and all circumstances.#
>
> I think that at least on linux we have more than enough space here:
>
> $ find /usr/include -type f | xargs grep ' NAME_MAX' | grep define
> /usr/include/linux/limits.h:#define NAME_MAX 255 /* # chars in a file name */
>
> $ find /usr/include -type f | xargs grep ' HOST_NAME_MAX' | grep define
> /usr/include/i386-linux-gnu/bits/local_lim.h:#define HOST_NAME_MAX 64
> /usr/include/x86_64-linux-gnu/bits/local_lim.h:#define HOST_NAME_MAX 64
>
Okay, works for me :)
--
Thanks,
Anatoly
next prev parent reply other threads:[~2019-11-06 10:37 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-16 1:59 [dpdk-stable] [PATCH] fbarray: get fbarrays from containerized secondary ogawa.yasufumi
2019-04-16 3:43 ` [dpdk-stable] [PATCH v2 0/1] Get " ogawa.yasufumi
2019-04-16 3:43 ` [dpdk-stable] [PATCH v2 1/1] fbarray: get " ogawa.yasufumi
2019-07-04 20:17 ` [dpdk-stable] [dpdk-dev] " Thomas Monjalon
2019-07-05 8:53 ` [dpdk-stable] " Burakov, Anatoly
2019-07-09 10:22 ` [dpdk-stable] [dpdk-dev] " Yasufumi Ogawa
2019-07-09 10:24 ` Burakov, Anatoly
2019-07-09 10:26 ` Burakov, Anatoly
2019-07-11 9:37 ` Yasufumi Ogawa
2019-07-11 9:43 ` Burakov, Anatoly
2019-07-11 10:31 ` [dpdk-stable] [PATCH v3 0/1] " yasufum.o
2019-07-11 10:31 ` [dpdk-stable] [PATCH v3 1/1] " yasufum.o
2019-07-11 10:53 ` Burakov, Anatoly
2019-07-11 11:57 ` Yasufumi Ogawa
2019-07-11 13:14 ` Burakov, Anatoly
2019-07-12 2:22 ` Yasufumi Ogawa
2019-07-22 1:06 ` Ogawa Yasufumi
2019-07-22 9:33 ` Burakov, Anatoly
2019-07-22 9:25 ` Burakov, Anatoly
2019-07-24 8:20 ` [dpdk-stable] [PATCH v4 0/1] " yasufum.o
2019-07-24 8:20 ` [dpdk-stable] [PATCH v4 1/1] " yasufum.o
2019-07-24 9:59 ` Burakov, Anatoly
2019-07-30 8:16 ` Thomas Monjalon
2019-07-30 9:18 ` Burakov, Anatoly
2019-07-31 5:48 ` Yasufumi Ogawa
2019-10-11 9:36 ` David Marchand
2019-10-25 15:36 ` David Marchand
2019-10-25 19:54 ` Yasufumi Ogawa
2019-10-26 16:15 ` David Marchand
2019-10-26 18:11 ` Yasufumi Ogawa
2019-10-28 8:07 ` [dpdk-stable] [PATCH v5 0/1] fbarray: fix duplicated fbarray file in secondary yasufum.o
2019-10-28 8:07 ` [dpdk-stable] [PATCH v5 1/1] " yasufum.o
2019-10-29 12:03 ` [dpdk-stable] [dpdk-dev] " Ananyev, Konstantin
2019-10-30 13:42 ` Yasufumi Ogawa
2019-10-30 19:00 ` Ananyev, Konstantin
2019-10-31 10:03 ` Yasufumi Ogawa
2019-10-31 10:32 ` Ananyev, Konstantin
2019-11-01 9:04 ` [dpdk-stable] [PATCH v6 0/1] " yasufum.o
2019-11-01 9:04 ` [dpdk-stable] [PATCH v6 1/1] " yasufum.o
2019-11-01 12:01 ` Ananyev, Konstantin
2019-11-04 10:20 ` Burakov, Anatoly
2019-11-05 10:13 ` David Marchand
2019-11-05 11:31 ` Burakov, Anatoly
2019-11-05 11:41 ` Ananyev, Konstantin
2019-11-06 10:37 ` Burakov, Anatoly [this message]
2019-11-08 3:19 ` Yasufumi Ogawa
2019-11-13 21:43 ` [dpdk-stable] [PATCH v7 0/1] " yasufum.o
2019-11-13 21:43 ` [dpdk-stable] [PATCH v7 1/1] " yasufum.o
2019-11-14 10:01 ` Burakov, Anatoly
2019-11-14 11:42 ` Yasufumi Ogawa
2019-11-14 12:27 ` David Marchand
2019-11-26 19:40 ` Yasufumi Ogawa
2019-11-27 10:26 ` Burakov, Anatoly
2019-11-14 12:55 ` David Marchand
2019-11-14 17:32 ` Ananyev, Konstantin
2023-06-13 16:51 ` [dpdk-dev] [PATCH] fbarray: get fbarrays from containerized secondary Stephen Hemminger
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