[External] Re: [PATCH v4] eal: fix eal init may failed when too much continuous memsegs under legacy mode

[Burakov, Anatoly]

On 6/9/2023 9:35 AM, Fengnan Chang wrote:
> David Marchand <david.marchand at redhat.com> 于2023年6月8日周四 04:33写道：
>>
>> On Mon, May 29, 2023 at 1:23 PM Fengnan Chang
>> <changfengnan at bytedance.com> wrote:
>>>
>>> Under legacy mode, if the number of continuous memsegs greater
>>> than RTE_MAX_MEMSEG_PER_LIST, eal init will failed even though
>>> another memseg list is empty, because only one memseg list used
>>> to check in remap_needed_hugepages.
>>> Fix this by make remap_segment return how many segments mapped,
>>> remap_segment try to map most contiguous segments it can, if
>>> exceed it's capbility, remap_needed_hugepages will continue to
>>> map other left pages.
>>>
>>> For example:
>>> hugepage configure:
>>> cat /sys/devices/system/node/node*/hugepages/hugepages-2048kB/nr_hugepages
>>> 10241
>>> 10239
>>>
>>> startup log:
>>> EAL: Detected memory type: socket_id:0 hugepage_sz:2097152
>>> EAL: Detected memory type: socket_id:1 hugepage_sz:2097152
>>> EAL: Creating 4 segment lists: n_segs:8192 socket_id:0 hugepage_sz:2097152
>>> EAL: Creating 4 segment lists: n_segs:8192 socket_id:1 hugepage_sz:2097152
>>> EAL: Requesting 13370 pages of size 2MB from socket 0
>>> EAL: Requesting 7110 pages of size 2MB from socket 1
>>> EAL: Attempting to map 14220M on socket 1
>>> EAL: Allocated 14220M on socket 1
>>> EAL: Attempting to map 26740M on socket 0
>>> EAL: Could not find space for memseg. Please increase 32768 and/or 65536 in
>>> configuration.
>>> EAL: Couldn't remap hugepage files into memseg lists
>>> EAL: FATAL: Cannot init memory
>>> EAL: Cannot init memory
>>
>> We are missing a Fixes: tag and this is backport material, right?
> Yes, this patch need cc stable at dpdk.org
>>
>>
>>>
>>> Signed-off-by: Fengnan Chang <changfengnan at bytedance.com>
>>> Signed-off-by: Lin Li <lilintjpu at bytedance.com>
>>
>> Can I update Lin Li existing entry in .mailmap? Or is this a different person?
> Please help update in .mailmap, same person, thanks.
>>
>>
>>> Signed-off-by: Burakov Anatoly <anatoly.burakov at intel.com>
>> Anatoly Burakov*
>>
>>> Reviewed-by: Anatoly Burakov <anatoly.burakov at intel.com>
>>
>> Strange to have both SoB and Review tag from Anatoly.
> Maybe just leave SoB ? cc @ Anatoly

The signoff is there because I suggested an alternative implementation 
in comments. I'm OK with just leaving Review :)

>>
>>
>>> ---
>>>   lib/eal/linux/eal_memory.c | 51 +++++++++++++++++++++++++++-----------
>>
>> Is this issue affecting only Linux?
> Yes，Windows and FreeBSD is fine.
>>
>>
>>
>> --
>> David Marchand
>>

-- 
Thanks,
Anatoly