Re: [Qemu-devel] [PATCH] tests: Set read-zeroes on for null-co driver

From: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
To: Thomas Huth <thuth@redhat.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"qemu-block@nongnu.org" <qemu-block@nongnu.org>
Cc: "kwolf@redhat.com" <kwolf@redhat.com>,
	"lvivier@redhat.com" <lvivier@redhat.com>,
	"hare@suse.com" <hare@suse.com>,
	Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
	Denis Lunev <den@virtuozzo.com>,
	"armbru@redhat.com" <armbru@redhat.com>,
	"keith.busch@intel.com" <keith.busch@intel.com>,
	"kraxel@redhat.com" <kraxel@redhat.com>,
	"stefanha@redhat.com" <stefanha@redhat.com>,
	"pbonzini@redhat.com" <pbonzini@redhat.com>,
	"fam@euphon.net" <fam@euphon.net>
Subject: Re: [Qemu-devel] [PATCH] tests: Set read-zeroes on for null-co driver
Date: Tue, 13 Aug 2019 10:12:56 +0000	[thread overview]
Message-ID: <2a94e0ad-b66f-5f4e-94a7-639ff601cb92@virtuozzo.com> (raw)
In-Reply-To: <a2be1222-07f4-919b-7191-e6ec78c41bad@redhat.com>

On 13/08/2019 11:46, Thomas Huth wrote:
> On 7/30/19 3:23 PM, Andrey Shinkevich wrote:
>>
>>
>> On 30/07/2019 15:59, Thomas Huth wrote:
>>> On 30/07/2019 14.52, Thomas Huth wrote:
>>>> On 29/07/2019 14.46, Andrey Shinkevich wrote:
>>>>> This patch is to reduce the number of Valgrind report messages about
>>>>> using uninitialized memory with the null-co driver. It helps to filter
>>>>> real memory issues and is the same work done for the iotests with the
>>>>> commit ID a6862418fec4072.
>>>>>
>>>>> Suggested-by: Kevin Wolf <kwolf@redhat.com>
>>>>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>>>>> ---
>>>> [...]
>>>>> diff --git a/tests/test-blockjob-txn.c b/tests/test-blockjob-txn.c
>>>>> index 86606f9..7da9216 100644
>>>>> --- a/tests/test-blockjob-txn.c
>>>>> +++ b/tests/test-blockjob-txn.c
>>>>> @@ -15,6 +15,7 @@
>>>>>    #include "qemu/main-loop.h"
>>>>>    #include "block/blockjob_int.h"
>>>>>    #include "sysemu/block-backend.h"
>>>>> +#include "qapi/qmp/qdict.h"
>>>>>    
>>>>>    typedef struct {
>>>>>        BlockJob common;
>>>>> @@ -96,7 +97,9 @@ static BlockJob *test_block_job_start(unsigned int iterations,
>>>>>    
>>>>>        data = g_new0(TestBlockJobCBData, 1);
>>>>>    
>>>>> -    bs = bdrv_open("null-co://", NULL, NULL, 0, &error_abort);
>>>>> +    QDict *opt = qdict_new();
>>>>> +    qdict_put_str(opt, "file.read-zeroes", "on");
>>>>> +    bs = bdrv_open("null-co://", NULL, opt, 0, &error_abort);
>>>>>        g_assert_nonnull(bs);
>>>>
>>>> Not sure, but don't you need to also qdict_destroy_obj(opt) at the end
>>>> to avoid leaking memory? (Also in the other spots where you use
>>>> qdict_new() ...)
>>>
>>> Never mind, seems like bdrv_open() is doing an qobject_unref() on the
>>> options at the end, so I guess this should be fine...
>>>
>>> So in that case:
>>>
>>> Acked-by: Thomas Huth <thuth@redhat.com>
>>>
>>> (I assume this will be taken through the block tree? Let me know if you
>>> prefer the qtest tree instead)
>>
>> Thanks, Thomas!
>> I have run the patched program under the Valgrind to double check for
>> memory issues - no leak reported.
>> As for the branch, I would be happy with either.
> 
> Ok, FYI, I've queued this patch now in the qtest branch:
> 
>   https://gitlab.com/huth/qemu/commits/qtest-next
> 
>   Thomas
> 

Thank you Thomas,
I appreciate.

Andrey
-- 
With the best regards,
Andrey Shinkevich