Re: [PATCH v10 3/5] KVM: stats: Add documentation for binary statistics interface

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

 



On 17/06/21 07:56, Greg KH wrote:
On Thu, Jun 17, 2021 at 04:41:44AM +0000, Jing Zhang wrote:
+	struct kvm_stats_desc {
+		__u32 flags;
+		__s16 exponent;
+		__u16 size;
+		__u32 offset;
+		__u32 unused;
+		char name[0];
+	};

<snip>

+The ``unused`` fields are reserved for future support for other types of
+statistics data, like log/linear histogram.

you HAVE to set unused to 0 for now, otherwise userspace does not know
it is unused, right?

Jing, I think you planned to use it with other flags that are unused for now? But please do check that it's zero in the testcase.

It is not a pointer, it is the data itself.

+string starts at the end of ``struct kvm_stats_desc``.
+The maximum length (including trailing '\0') is indicated by ``name_size``
+in ``struct kvm_stats_header``.

I thought we were replacing [0] arrays with [], are you sure you should
be declaring this as [0]?  Same for all structures in this document (and
code).

In C code [0] is a bit more flexible than []. I think in this particular case [] won't work due to how the structures are declared. In the documentation [] is certainly clearer.

Paolo




[Index of Archives]     [LKML Archive]     [Linux ARM Kernel]     [Linux ARM]     [Git]     [Yosemite News]     [Linux SCSI]     [Linux Hams]

  Powered by Linux