Re: [Qemu-devel] [RFC PATCH 2/2] qemu-img: consider a zero number of I/O requests an invalid count

[Cleber Rosa]

On 11/12/18 9:38 AM, Philippe Mathieu-Daudé wrote:
> On 9/11/18 23:12, Cleber Rosa wrote:
>> It's debatable whether it makes sense to consider the bench command
>> successful when no I/O requests will be performed.  This changes the
>> behavior to consider a zero count of I/O requests an invalid value.
>> While at it, avoid using signed types for number of I/O requests.
>>
>> The image file used, is a simple raw image with 1K size.  There's a
>> obvious trade off between creating and reusing those images.  This is
>> an experiment in sharing those among tests.  It was created using:
>>
>>   mkdir -p tests/data/images/empty
>>   cd tests/data/images/empty
>>   qemu-img create raw 1K
>>
>> This relies on the Test's "get_data()", which by default looks for
>> data files on sources that map to various levels of specificity of a
>> test: file, test and additionally with variant and a symlink.
>>
>> One other possibility with regards to in-tree images, is to extend the
>> Test's "get_data()" API (which is extensible by design) and make the
>> common images directory a "source".  The resulting API usage would be
>> similar to:
>>
>>     self.get_data("empty/raw", source="common_images")
>>
>> or simply:
>>
>>     self.get_data("empty/raw")
>>
>> To look for "empty/raw" in any of the available sources.  That would
>> make the symlink unnecessary.
>>
>> Reference:
>> https://avocado-framework.readthedocs.io/en/65.0/api/core/avocado.core.html#avocado.core.test.TestData
>>
>> Signed-off-by: Cleber Rosa <address@hidden>
>> ---
>>   qemu-img.c                                  |   8 ++---
>>   tests/acceptance/qemu_img_bench.py          |  34 ++++++++++++++++++++
>>   tests/acceptance/qemu_img_bench.py.data/img |   1 +
>>   tests/data/images/empty/raw                 | Bin 0 -> 1024 bytes
>>   4 files changed, 39 insertions(+), 4 deletions(-)
>>   create mode 100644 tests/acceptance/qemu_img_bench.py
>>   create mode 120000 tests/acceptance/qemu_img_bench.py.data/img
>>   create mode 100644 tests/data/images/empty/raw
>>
>> diff --git a/qemu-img.c b/qemu-img.c
>> index 4c96db7ba4..7ffcdd1589 100644
>> --- a/qemu-img.c
>> +++ b/qemu-img.c
>> @@ -3960,7 +3960,7 @@ typedef struct BenchData {
>>       int bufsize;
>>       int step;
>>       int nrreq;
>> -    int n;
>> +    unsigned int n;
>>       int flush_interval;
>>       bool drain_on_flush;
>>       uint8_t *buf;
>> @@ -4051,7 +4051,7 @@ static int img_bench(int argc, char **argv)
>>       bool quiet = false;
>>       bool image_opts = false;
>>       bool is_write = false;
>> -    int count = 75000;
>> +    unsigned int count = 75000;
>>       int depth = 64;
>>       int64_t offset = 0;
>>       size_t bufsize = 4096;
>> @@ -4098,7 +4098,7 @@ static int img_bench(int argc, char **argv)
>>           {
>>               unsigned long res;
>>   -            if (qemu_strtoul(optarg, NULL, 0, &res) < 0 || res >
>> INT_MAX) {
>> +            if (qemu_strtoul(optarg, NULL, 0, &res) < 0 || res >
>> UINT_MAX || res <= 0) {
> 
> res is unsigned so can't be < 0.
> 

Right, that should have been obvious to me.

Thanks!
- Cleber.

>>                   error_report("Invalid request count specified");
>>                   return 1;
>>               }
>> @@ -4248,7 +4248,7 @@ static int img_bench(int argc, char **argv)
>>           .flush_interval = flush_interval,
>>           .drain_on_flush = drain_on_flush,
>>       };
>> -    printf("Sending %d %s requests, %d bytes each, %d in parallel "
>> +    printf("Sending %u %s requests, %d bytes each, %d in parallel "
>>              "(starting at offset %" PRId64 ", step size %d)\n",
>>              data.n, data.write ? "write" : "read", data.bufsize,
>> data.nrreq,
>>              data.offset, data.step);
>> diff --git a/tests/acceptance/qemu_img_bench.py
>> b/tests/acceptance/qemu_img_bench.py
>> new file mode 100644
>> index 0000000000..327524ad8f
>> --- /dev/null
>> +++ b/tests/acceptance/qemu_img_bench.py
>> @@ -0,0 +1,34 @@
>> +# Test for the basic qemu-img bench command
>> +#
>> +# Copyright (c) 2018 Red Hat, Inc.
>> +#
>> +# Author:
>> +#  Cleber Rosa <address@hidden>
>> +#
>> +# This work is licensed under the terms of the GNU GPL, version 2 or
>> +# later.  See the COPYING file in the top-level directory.
>> +
>> +import os
>> +
>> +from avocado_qemu import QemuImgTest
>> +from avocado.utils import process
>> +
>> +
>> +class Bench(QemuImgTest):
>> +    """
>> +    Runs the qemu-img tool with the bench command and different
>> +    options and verifies the expected outcome.
>> +
>> +    :avocado: enable
>> +    """
>> +    def check_invalid_count(self, count):
>> +        cmd = "%s bench -c %d %s" % (self.qemu_img_bin, count,
>> self.get_data("img"))
>> +        result = process.run(cmd, ignore_status=True)
>> +        self.assertEqual(1, result.exit_status)
>> +        self.assertIn(b"Invalid request count", result.stderr)
>> +
>> +    def test_zero_count(self):
>> +        self.check_invalid_count(0)
>> +
>> +    def test_negative_count(self):
>> +        self.check_invalid_count(-1)
>> diff --git a/tests/acceptance/qemu_img_bench.py.data/img
>> b/tests/acceptance/qemu_img_bench.py.data/img
>> new file mode 120000
>> index 0000000000..6d01ef2e85
>> --- /dev/null
>> +++ b/tests/acceptance/qemu_img_bench.py.data/img
>> @@ -0,0 +1 @@
>> +../../data/images/empty/raw
>> \ No newline at end of file
>> diff --git a/tests/data/images/empty/raw b/tests/data/images/empty/raw
>> new file mode 100644
>> index
>> 0000000000000000000000000000000000000000..06d7405020018ddf3cacee90fd4af10487da3d20
>>
>> GIT binary patch
>> literal 1024
>> ScmZQz7zLvtFd70QH3R?z00031
>>
>> literal 0
>> HcmV?d00001
>>