On 2020/07/31 8:09, Dmitry Fomichev wrote:
>
>
>> -----Original Message-----
>> From: Damien Le Moal <Damien.LeMoal@xxxxxxx>
>> Sent: Thursday, July 30, 2020 12:54 AM
>> To: Dmitry Fomichev <Dmitry.Fomichev@xxxxxxx>; Jens Axboe
>> <axboe@xxxxxxxxx>
>> Cc: fio@xxxxxxxxxxxxxxx; Shinichiro Kawasaki
>> <shinichiro.kawasaki@xxxxxxx>
>> Subject: Re: [PATCH v2 1/4] configure: improve libzbc version check
>>
>> On 2020/07/30 6:04, Dmitry Fomichev wrote:
>>> Avoid parsing pkg-config output and just use --atleast-version to
>>> check if libzbc is present and has an up to date version.
>>>
>>> Currently, support for libzbc ioengine is always included if libzbc is
>>> found at the build system. Add the option to disable libzbc ioengine
>>> support even if libzbc is found. This can be useful for
>>> cross-compilation.
>>>
>>> Signed-off-by: Dmitry Fomichev <dmitry.fomichev@xxxxxxx>
>>> ---
>>> configure | 28 +++++++++++++++-------------
>>> 1 file changed, 15 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/configure b/configure
>>> index 5925e94f..9a5f35f2 100755
>>> --- a/configure
>>> +++ b/configure
>>> @@ -213,6 +213,8 @@ for opt do
>>> ;;
>>> --enable-libnbd) libnbd="yes"
>>> ;;
>>> + --disable-libzbc) libzbc="no"
>>> + ;;
>>> --disable-tcmalloc) disable_tcmalloc="yes"
>>> ;;
>>> --enable-libaio-uring) libaio_uring="yes"
>>> @@ -256,6 +258,7 @@ if test "$show_help" = "yes" ; then
>>> echo "--with-ime= Install path for DDN's Infinite Memory Engine"
>>> echo "--enable-libiscsi Enable iscsi support"
>>> echo "--enable-libnbd Enable libnbd (NBD engine) support"
>>> + echo "--disable-libzbc Disable libzbc even if found"
>>
>> The message could simply be "Disable libzbc support".
>>
>>> echo "--disable-tcmalloc Disable tcmalloc support"
>>> echo "--enable-libaio-uring Enable libaio emulated over io_uring"
>>> echo "--dynamic-libengines Lib-based ioengines as dynamic libraries"
>>> @@ -2454,9 +2457,6 @@ fi
>>>
>>> ##########################################
>>> # libzbc probe
>>> -if test "$libzbc" != "yes" ; then
>>> - libzbc="no"
>>> -fi
>>> cat > $TMPC << EOF
>>> #include <libzbc/zbc.h>
>>> int main(int argc, char **argv)
>>> @@ -2466,19 +2466,21 @@ int main(int argc, char **argv)
>>> return zbc_open("foo=bar", O_RDONLY, &dev);
>>> }
>>> EOF
>>> -if compile_prog "" "-lzbc" "libzbc"; then
>>> - libzbcvermaj=$(pkg-config --modversion libzbc | sed 's/\.[0-9]*\.[0-
>> 9]*//')
>>> - if test "$libzbcvermaj" -ge "5" ; then
>>> - libzbc="yes"
>>> +if test "$libzbc" != "no" ; then
>>
>> If you make this:
>>
>> if test "$libzbc" = "yes" ; then
>>
>>> + if compile_prog "" "-lzbc" "libzbc"; then
>>> + minimum_libzbc=5
>>> + if $(pkg-config --atleast-version=$minimum_libzbc libzbc); then
>>> + libzbc="yes"
>>> + else
>>> + print_config "libzbc engine" "libzbc version $minimum_libzbc or above
>> required"
>>> + libzbc="no"
>>> + fi
>>
>> then you can simplify the above by reversing the if condition,
>>
>>> else
>>> - print_config "libzbc engine" "Unsupported libzbc version (version 5 or
>> above required)"
>>> + if test "$libzbc" = "yes" ; then
>>
>> and you do not need this if. Note that I think you need to initialize the libzbc
>> variable to "yes" by default for this to work.
>>
>
> Right now, there is no default for libzbc ioengine support. If libzbc is found by
> configure, then libzbc ioengine will always be added. The new flag, --disable-libzbc,
> prevents adding support for libzbc ioengine in this case. If libzbc is not present,
> fio configure is not failed with "feature not found".
>
> Currently, no other feature in fio configure has the default option of "yes" and all
> features that can be explicitly set to yes are set so by script command line options.
> If a feature is set to yes and is not available, configure fails with "feature not found"
> error. Do we really want configure to fail on any system that doesn't have libzbc
> unless --disable-libzbc is added to the command line?
>
> There is one feature option, "disable_lex", with the default value, "". I guess we
> could define libzbc option the same way to improve code clarity.
Yes. That matches what Sitsofe commented too. That would mean, enable is found
if --disable-libzbc is not set, but do not fail configure if not found.
>
>>> + feature_not_found "libzbc" "libzbc or libzbc/zbc.h"
>>> + fi
>>> libzbc="no"
>>> fi
>>> -else
>>> - if test "$libzbc" = "yes" ; then
>>> - feature_not_found "libzbc" "libzbc or libzbc/zbc.h"
>>> - fi
>>> - libzbc="no"
>>> fi
>>> print_config "libzbc engine" "$libzbc"
>>>
>>>
>>
>>
>> --
>> Damien Le Moal
>> Western Digital Research
>
--
Damien Le Moal
Western Digital Research
