Re: [PATCH v2 09/10] libxl: Fix libxl_set_memory_target return value

From: George Dunlap <George.Dunlap@eu.citrix.com>
To: Paulina Szubarczyk <paulinaszubarczyk@gmail.com>
Cc: "Wei Liu" <wei.liu2@citrix.com>,
	"Ian Campbell" <ian.campbell@citrix.com>,
	"Dario Faggioli" <dario.faggioli@citrix.com>,
	"Ian Jackson" <ian.jackson@eu.citrix.com>,
	xen-devel <xen-devel@lists.xenproject.org>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v2 09/10] libxl: Fix libxl_set_memory_target return value
Date: Wed, 6 Apr 2016 14:53:17 +0100	[thread overview]
Message-ID: <CAFLBxZYspRRXMGHSf5HZrBFmZ6UU=06=AJxFZLSvqTNFJd66DQ@mail.gmail.com> (raw)
In-Reply-To: <1459948881.21096.9.camel@localhost>

On Wed, Apr 6, 2016 at 2:21 PM, Paulina Szubarczyk
<paulinaszubarczyk@gmail.com> wrote:
> On Wed, 2016-04-06 at 13:54 +0100, George Dunlap wrote:
>> On Wed, Apr 6, 2016 at 12:46 PM, Paulina Szubarczyk
>> <paulinaszubarczyk@gmail.com> wrote:
>> > From: George Dunlap <George.Dunlap@eu.citrix.com>
>> >
>> > libxl_set_memory_target seems to have the following return values:
>> >
>> > * 1 on failure, if the failure happens because of a xenstore error *or*
>> > * invalid target
>> >
>> > * -1 if the setmaxmem hypercall
>> >
>> > * -errno if the set_pod_target hypercall target fails
>> >
>> > * 0 on success
>> >
>> > Make it consistently return ERROR_FAIL on failure, unless the
>> > parameters were invalid, in which case return ERROR_INVAL.
>> >
>> > In accordance with CODING_SYTLE:
>> >
>> > 1. Leave rc uninitialized, and set when an error is detected
>> >
>> > 2. Use 'r' for return values to functions whose return values are a
>> > different error space (like xc_domain_setmaxmem and
>> > xc_domain_set_pod_target)
>> >
>> > ---
>> > Changed since v1:
>> >
>> > 3. Use 'lrc' for return values to local functions libxl__*
>> > where a failure means retry, rather than fail the whole function
>> > (libxl__fill_dom0_memory_info), to reduce the risk of that.
>> >
>> > Signed-off-by: George Dunlap <George.Dunlap@eu.citrix.com>
>> > Signed-off-by: Paulina Szubarczyk <paulinaszubarczyk@gmail.com>
>>
>> FYI everything after the "---" will be discarded on commit; so you
>> need all the tags (signed-off-by, acked-by, &c) to be before that.
>>
>>  -George
>>
> I did not know that. Thank you. I was suggested by the wiki page,
> where the example resend comments starts after the "---" but
> the tags you mentioned are earlier.
>
> But that confused me a bit, so after that "---" there should be comments
> for reviewers rather then information about changes.

Yes; anything after the --- will automatically be erased by git when
it's checked in.  So you use that to include information that is
useful for reviewers but you don't want to be checked in -- for
example, the difference between versions.

>
> Should I re-send it now or may I do it with the changes after review?

Many committers don't mind making that sort of change when they check
things in; and if there are comments on the series, you may have to
re-send it anyway.  So it's a good idea to just wait until you either
1) know you have to re-send it for other reasons, or 2) are asked by a
committer to re-send it (or not).

 -George

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