-----Original Message-----
From: Jonas Pfefferle [mailto:peppe...@japf.ch]
Sent: Wednesday, January 3, 2018 5:22 PM
To: Xueming(Steven) Li <xuemi...@mellanox.com>; Burakov, Anatoly
<anatoly.bura...@intel.com>
Cc: dev@dpdk.org; jianfeng....@intel.com; Thomas Monjalon
<tho...@monjalon.net>
Subject: Re: [dpdk-dev] [PATCH] mem: warn if address hint is not
respected
Hi Xueming,
Correct --base-virtaddr was introduced for that purpose. There are
multiple reasons why the address layout of the secondary process
might
look different: reasons you mentioned in 2), ASLR etc. I believe
there is
no way to avoid this in real world use cases. The reason for this
particular patch is that the address hint (--base-virtaddr) is
sometimes
not respected and the kernel falls back to just reserving any
address it
can find to satisfy the mapping (see discussion on the patch), i.e.
effectively rendering --base-virtaddr useless.
Regards,
Jonas (new email address)
On Tue, 26 Dec 2017 15:56:10 +0000
"Xueming(Steven) Li" <xuemi...@mellanox.com> wrote:
> Hi Jonas,
>
> Seems you are trying to use --base-virtaddr to resolve address
>conflicts in secondary, I'm wondering how this happened and how to
>avoid it:
> 1. what's your hugepage side? Hugepage mmap is size aligned, maybe
1G
>works?
> 2. is there more libs loaded in secondary process or memory usage
>before EAL init?
> 3. Since address allocated in one direction, I'm thinking to
reserve a
>larger "hop" address space as MAP_ANONYMOUS, allocate hugepage,
then
>release "hop". That essentially reserve an address space big
enough
>for secondary, and most important the hop size is easy to estimate
>than --base-virtaddr.
>
> Thanks,
> Xueming(Steven)
>
>> -----Original Message-----
>> From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Jonas
>>Pfefferle1
>> Sent: Wednesday, November 8, 2017 7:52 PM
>> To: Burakov, Anatoly <anatoly.bura...@intel.com>
>> Cc: dev@dpdk.org; jianfeng....@intel.com; Thomas Monjalon
>><tho...@monjalon.net>
>> Subject: Re: [dpdk-dev] [PATCH] mem: warn if address hint is not
>>respected
>>
>> "Burakov, Anatoly" <anatoly.bura...@intel.com> wrote on
11/07/2017
>> 02:54:24
>> PM:
>>
>> > From: "Burakov, Anatoly" <anatoly.bura...@intel.com>
>> > To: Thomas Monjalon <tho...@monjalon.net>
>> > Cc: dev@dpdk.org, Jonas Pfefferle <j...@zurich.ibm.com>,
>> jianfeng....@intel.com
>> > Date: 11/07/2017 02:54 PM
>> > Subject: Re: [dpdk-dev] [PATCH] mem: warn if address hint is
not
>> respected
>> >
>> > On 06-Nov-17 8:26 PM, Thomas Monjalon wrote:
>> > > 31/10/2017 10:08, Jonas Pfefferle:
>> > >> Print a warning if the --base-virtaddr hint is not respected
>>since
>> > >> this might lead to problems when mapping memory in the
>>secondary
>> > >> process.
>> > >>
>> > >> Signed-off-by: Jonas Pfefferle <j...@zurich.ibm.com>
>> > >
>> > > Anatoly, please review this patch.
>> > > It does not seem to fix something, so it is candidate for
18.02.
>> > >
>> >
>> > For some reason my Thunderbird ate the original email, so i'll
>>reply
>> > to this one.
>> >
>> > One nitpick would be that we're calling get_virtual_area many
>>times
>> > and it would probably be a good idea to make pagesize static
and
>>call
>> > sysconf only once. Otherwise,
>>
>> We should address this in a separate patch and introduce a
pagesize
>>function for everyone to use. sysconf is used like this all over
the
>>place.
>>
>> >
>> > Acked-by: Anatoly Burakov <anatoly.bura...@intel.com>
>> >
>> > --
>> > Thanks,
>> > Anatoly
>> >
