Re: [RFC 0/4] pci/sriov: support VFs dynamic addition

Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
2022-11-13T13:49:46Z

在 2022/11/12 7:07, Bjorn Helgaas 写道:
> On Fri, Nov 11, 2022 at 10:27:18PM +0800, Longpeng(Mike) wrote:
>> From: Longpeng <longpeng2@huawei.com>
>>
>> We can enable SRIOV and add VFs by /sys/bus/pci/devices/..../sriov_numvfs, but
>> this operation needs to spend lots of time if there has a large amount of VFs.
>>
>> For example, if the machine has 10 PFs and 250 VFs per-PF, enable all the VFs
>> concurrently would cost about 200-250ms. However most of them are not need to be
>> used at the moment, so we can enable SRIOV first but add VFs on demand.
>>
>> This series introduces two interfaces:
>> 1. sriov_numvfs_no_scan: enable SRIOV without add the VFs.
>> 2. sriov_scan_vf_id: add a specific VF.
>>
>> Longpeng (4):
>> pci/sriov: extract sriov_numvfs common helper
>> pci/sriov: add vf_bitmap to mark the vf id allocation
>> pci/sriov: add sriov_numfs_no_scan interface
>> pci/sriov: add sriov_scan_vf_id interface
>
> When you respond to Leon's questions, please also spend a little time
> to look at the iov.c history and coding style and follow it, so we
> don't have to waste time commenting on or fixing trivial things.
>
Okay, thanks for your valuable suggestions.

> For example, there are no previous subject lines for that file that
> start with "pci/sriov". Don't make up a new prefix; use what's been
> done in the past. And follow the style of capitalizing the first word
> after the prefix.
>
> There are a few comments that look like they are more than 80 columns.
> Again unlike everything else in the file.
>
> The PCIe spec spells it "SR-IOV", not "sriov". Do the same in your
> commit logs and comments.
>
> Capitalize "VF" consistently. I see "VF" and "vf" used randomly.
>
> Sysfs changes require documention updates, e.g., in
> Documentation/ABI/testing/sysfs-bus-pci.
> .