[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [RFC] exec: eliminate ram naming issue as migration

From: Tan, Jianfeng
Subject: Re: [Qemu-devel] [RFC] exec: eliminate ram naming issue as migration
Date: Thu, 8 Feb 2018 09:20:45 +0800
User-agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0

On 2/7/2018 8:06 PM, Igor Mammedov wrote:
On Wed, 7 Feb 2018 07:49:58 +0000
"Tan, Jianfeng" <address@hidden> wrote:

-----Original Message-----
From: Paolo Bonzini [mailto:address@hidden
Sent: Tuesday, February 6, 2018 1:32 AM
To: Igor Mammedov
Cc: Tan, Jianfeng; address@hidden; Jason Wang; Maxime Coquelin;
Michael S . Tsirkin
Subject: Re: [Qemu-devel] [RFC] exec: eliminate ram naming issue as

On 05/02/2018 18:15, Igor Mammedov wrote:
Then we would have both ram block named pc.ram:
               Block Name    PSize
                       pc.ram     4 KiB
       /objects/pc.ram    2 MiB

But I assume it's a corner case which not really happen.
Yeah, you're right. :/  I hadn't thought of hotplug.  It can happen indeed.
perhaps we should fail object_add memory-backend-foo if it resulted
in creating ramblock with duplicate id
Note that it would only be duplicated with Jianfeng's patch.  So I'm
worried that his patch is worse than what we have now, because it may
create conflicts with system RAMBlock names are not necessarily
predictable.  Right now, -object creates RAMBlock names that are nicely
constrained within /object/.
So we are trading off between the benefit it takes and the bad effect it brings.

I'm wondering if the above example is the only failed case this patch leads to, i.e, only there is 
a ram named "pc.ram" and "/object/pc.ram" in the src VM?

Please also consider the second option, that adding an alias name for RAMBlock; 
I'm not a big fan for that one, as it just pushes the problem to 
looking at provided CLI examples it's configuration issue on src and dst,
one shall not mix numa and non numa variants.

Aha, that's another thing we also want to change. We now add numa at dst node, only because without -numa, we cannot set up the file-baked memory with share=on.

For example, "-m xG -mem-path xxx" can set up a file-baked memory, but the file is not share-able.

Or any other suggestions?
Fix configuration, namely dst side of it (i.e. use the same -m only variant
without -numa as it's on src).

BTW, what are you trying to achieve adding -numa on dst?

See above reply.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]