Coiby Xu <coxu(a)redhat.com> 于2022年4月25日周一 11:10写道:
On Sat, Apr 23, 2022 at 10:32:28PM +0800, Kairui Song wrote:
>Coiby Xu <coxu(a)redhat.com> 于2022年4月2日周六 11:24写道:
[...]
>> This patch set reuses NetworkManager connection profiles to set up kdump
>> network. It also reduces the memory consumption of network drivers and
>> fix other issues at the same time. Here are the bug list that addressed by
>> this patch set on bugzilla,
>> - Bug 1962421 - [RHEL-9]"eth0: Failed to rename network interface 3 from
'eth0' to 'kdump-eth0': File exists"
>> - Bug 2064708 - kdump: mkdumprd: failed to make kdump initrd for bridge
network on z15 z/vm
>> - bugs related to OOM caused by network driver
>
>Hi Coiby,
Hi Kairui,
Glad to see you again:)
>
>This looks great, but one thing I don't understand, how is this going
>to help reduce the memory consumption? Shoudn't network drivers be the
>same, no matter how they are loaded?
I forgot to temporarily remove Bug 1958587 from the list which may
confuse you. Currently this version only saves memory for the case
where a network driver manages multiple NICs in [RFC 04/13] don't let
NetworkManager manage unneeded network interfaces. Because when
NetworkManager manges a NIC, it will trigger the driver to allocate
memory resources (for rx or tx ring buffers for example) regardless of
the NIC is active or not. By asking NM to stopping managing these
unneeded devices, it could save kdump memory. I planned to use dracut's
"--hostonly-nics" introduced by you to get rid of unnecessary NIC
drivers in this version as well but currently it's in the dracut kdump
module we find out the NICs needed by kdump and as a dracut module it
can't add the "--hostonly-nics" option to dracut. So I created a dracut
PR [1] to allow specifying empty --hostonly-nics. In next version I'll
only install the network drivers needed as [1] has been merged.
Ah, I get it now. I was thinking about how should kexec-tools
determine which interface to kept when implementing that
--hostonly-nic, this patch is a clean and great answer, thanks!