diff mbox series

[v4,2/9] event/dlb2: skip configuration if no eventdev lib

Message ID 20230623150708.2203918-3-bruce.richardson@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series expand list of optional libraries |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Bruce Richardson June 23, 2023, 3:07 p.m. UTC 
  While the build system will skip building most libs and drivers when a
dependency is missing for a component, for DLB2 driver, the
"static_rte_eventdev" object is referenced inside the meson.build file
itself, which will cause crashes if it doesn't exist i.e. if eventdev is
disabled. Prevent this issue by skipping processing the file if no
eventdev. [The build system will still report missing dependency, as the
dependency is set by default for all eventdev drivers]

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
 drivers/event/dlb2/meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

David Marchand June 28, 2023, 10:19 a.m. UTC | #1 
On Fri, Jun 23, 2023 at 5:07 PM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> While the build system will skip building most libs and drivers when a
> dependency is missing for a component, for DLB2 driver, the
> "static_rte_eventdev" object is referenced inside the meson.build file
> itself, which will cause crashes if it doesn't exist i.e. if eventdev is
> disabled. Prevent this issue by skipping processing the file if no
> eventdev. [The build system will still report missing dependency, as the
> dependency is set by default for all eventdev drivers]
>
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

Could we evaluate the class "std_deps" before jumping to each driver
meson.build?
David Marchand June 29, 2023, 9:39 a.m. UTC | #2 
On Wed, Jun 28, 2023 at 12:19 PM David Marchand
<david.marchand@redhat.com> wrote:
>
> On Fri, Jun 23, 2023 at 5:07 PM Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > While the build system will skip building most libs and drivers when a
> > dependency is missing for a component, for DLB2 driver, the
> > "static_rte_eventdev" object is referenced inside the meson.build file
> > itself, which will cause crashes if it doesn't exist i.e. if eventdev is
> > disabled. Prevent this issue by skipping processing the file if no
> > eventdev. [The build system will still report missing dependency, as the
> > dependency is set by default for all eventdev drivers]
> >
> > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
>
> Could we evaluate the class "std_deps" before jumping to each driver
> meson.build?

Hum, with my suggestion, we lose the opportunity for drivers to
rewrite completely their "deps".
I doubt we have cases where it really matters, but if this revealed to
be necessary, such driver may be directly referenced in
drivers/meson.build like we do for common/cnxk & friends.

To illustrate the idea, I pushed your series along patches of mine
(target is v23.11) in my github repo.
https://github.com/david-marchand/dpdk/commit/enable_libs~8
Bruce Richardson July 18, 2023, 9:09 a.m. UTC | #3 
On Thu, Jun 29, 2023 at 11:39:53AM +0200, David Marchand wrote:
> On Wed, Jun 28, 2023 at 12:19 PM David Marchand
> <david.marchand@redhat.com> wrote:
> >
> > On Fri, Jun 23, 2023 at 5:07 PM Bruce Richardson
> > <bruce.richardson@intel.com> wrote:
> > >
> > > While the build system will skip building most libs and drivers when a
> > > dependency is missing for a component, for DLB2 driver, the
> > > "static_rte_eventdev" object is referenced inside the meson.build file
> > > itself, which will cause crashes if it doesn't exist i.e. if eventdev is
> > > disabled. Prevent this issue by skipping processing the file if no
> > > eventdev. [The build system will still report missing dependency, as the
> > > dependency is set by default for all eventdev drivers]
> > >
> > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> >
> > Could we evaluate the class "std_deps" before jumping to each driver
> > meson.build?
> 
> Hum, with my suggestion, we lose the opportunity for drivers to
> rewrite completely their "deps".
> I doubt we have cases where it really matters, but if this revealed to
> be necessary, such driver may be directly referenced in
> drivers/meson.build like we do for common/cnxk & friends.
> 
> To illustrate the idea, I pushed your series along patches of mine
> (target is v23.11) in my github repo.
> https://github.com/david-marchand/dpdk/commit/enable_libs~8
> 
I don't think we should need to worry too much about the case of a driver
needing to rewrite deps. The standard deps should really just be the
minimal deps for a class.

However, for the implementation of that check, I'm not sure I like the
approach of checking std_deps in a loop for each driver. Firstly, the logic
inside the per-driver block is already pretty complicated, but secondly, I
think we can skip that loop entirely if the standard deps for a class are
not met. I think instead it would be better to process std_deps value once
immediately after the "subdir(class)" line, and if not all deps are
present, just loop through all the driver directories for that class
immediately and mark them as unbuildable, before just moving on to the next
class.

WDYT?
/Bruce
David Marchand Aug. 1, 2023, 8:36 a.m. UTC | #4 
Hello Bruce,

On Tue, Jul 18, 2023 at 11:10 AM Bruce Richardson
<bruce.richardson@intel.com> wrote:
>
> On Thu, Jun 29, 2023 at 11:39:53AM +0200, David Marchand wrote:
> > On Wed, Jun 28, 2023 at 12:19 PM David Marchand
> > <david.marchand@redhat.com> wrote:
> > >
> > > On Fri, Jun 23, 2023 at 5:07 PM Bruce Richardson
> > > <bruce.richardson@intel.com> wrote:
> > > >
> > > > While the build system will skip building most libs and drivers when a
> > > > dependency is missing for a component, for DLB2 driver, the
> > > > "static_rte_eventdev" object is referenced inside the meson.build file
> > > > itself, which will cause crashes if it doesn't exist i.e. if eventdev is
> > > > disabled. Prevent this issue by skipping processing the file if no
> > > > eventdev. [The build system will still report missing dependency, as the
> > > > dependency is set by default for all eventdev drivers]
> > > >
> > > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > >
> > > Could we evaluate the class "std_deps" before jumping to each driver
> > > meson.build?
> >
> > Hum, with my suggestion, we lose the opportunity for drivers to
> > rewrite completely their "deps".
> > I doubt we have cases where it really matters, but if this revealed to
> > be necessary, such driver may be directly referenced in
> > drivers/meson.build like we do for common/cnxk & friends.
> >
> > To illustrate the idea, I pushed your series along patches of mine
> > (target is v23.11) in my github repo.
> > https://github.com/david-marchand/dpdk/commit/enable_libs~8
> >
> I don't think we should need to worry too much about the case of a driver
> needing to rewrite deps. The standard deps should really just be the
> minimal deps for a class.
>
> However, for the implementation of that check, I'm not sure I like the
> approach of checking std_deps in a loop for each driver. Firstly, the logic
> inside the per-driver block is already pretty complicated, but secondly, I
> think we can skip that loop entirely if the standard deps for a class are
> not met. I think instead it would be better to process std_deps value once
> immediately after the "subdir(class)" line, and if not all deps are
> present, just loop through all the driver directories for that class
> immediately and mark them as unbuildable, before just moving on to the next
> class.

Skipping this loop makes the change smaller and the logic in
drivers/meson.build easier to understand.
We lose the exhaustive summary for disabled content (before, every
disabled driver was logged with the associated reason), but we can
still log the reason why a class is disabled.

Your suggestion looks good to me, let me send a patch.
Bruce Richardson Aug. 1, 2023, 9:17 a.m. UTC | #5 
On Tue, Aug 01, 2023 at 10:36:30AM +0200, David Marchand wrote:
> Hello Bruce,
> 
> On Tue, Jul 18, 2023 at 11:10 AM Bruce Richardson
> <bruce.richardson@intel.com> wrote:
> >
> > On Thu, Jun 29, 2023 at 11:39:53AM +0200, David Marchand wrote:
> > > On Wed, Jun 28, 2023 at 12:19 PM David Marchand
> > > <david.marchand@redhat.com> wrote:
> > > >
> > > > On Fri, Jun 23, 2023 at 5:07 PM Bruce Richardson
> > > > <bruce.richardson@intel.com> wrote:
> > > > >
> > > > > While the build system will skip building most libs and drivers when a
> > > > > dependency is missing for a component, for DLB2 driver, the
> > > > > "static_rte_eventdev" object is referenced inside the meson.build file
> > > > > itself, which will cause crashes if it doesn't exist i.e. if eventdev is
> > > > > disabled. Prevent this issue by skipping processing the file if no
> > > > > eventdev. [The build system will still report missing dependency, as the
> > > > > dependency is set by default for all eventdev drivers]
> > > > >
> > > > > Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> > > >
> > > > Could we evaluate the class "std_deps" before jumping to each driver
> > > > meson.build?
> > >
> > > Hum, with my suggestion, we lose the opportunity for drivers to
> > > rewrite completely their "deps".
> > > I doubt we have cases where it really matters, but if this revealed to
> > > be necessary, such driver may be directly referenced in
> > > drivers/meson.build like we do for common/cnxk & friends.
> > >
> > > To illustrate the idea, I pushed your series along patches of mine
> > > (target is v23.11) in my github repo.
> > > https://github.com/david-marchand/dpdk/commit/enable_libs~8
> > >
> > I don't think we should need to worry too much about the case of a driver
> > needing to rewrite deps. The standard deps should really just be the
> > minimal deps for a class.
> >
> > However, for the implementation of that check, I'm not sure I like the
> > approach of checking std_deps in a loop for each driver. Firstly, the logic
> > inside the per-driver block is already pretty complicated, but secondly, I
> > think we can skip that loop entirely if the standard deps for a class are
> > not met. I think instead it would be better to process std_deps value once
> > immediately after the "subdir(class)" line, and if not all deps are
> > present, just loop through all the driver directories for that class
> > immediately and mark them as unbuildable, before just moving on to the next
> > class.
> 
> Skipping this loop makes the change smaller and the logic in
> drivers/meson.build easier to understand.
> We lose the exhaustive summary for disabled content (before, every
> disabled driver was logged with the associated reason), but we can
> still log the reason why a class is disabled.
> 

When we "subdir" into the driver class directory to get the standard
dependencies, we also get the list of drivers of that class. We can then
loop through those drivers to individually mark them as disabled for the
summary. It would be a fairly small loop, and would keep things consistent
with what we have now.

On the other hand, having a single line for a whole class of drivers may
make the summary more useful!

/Bruce
diff mbox series

Patch

diff --git a/drivers/event/dlb2/meson.build b/drivers/event/dlb2/meson.build
index 515d1795fe..8cede61593 100644
--- a/drivers/event/dlb2/meson.build
+++ b/drivers/event/dlb2/meson.build
@@ -7,7 +7,7 @@  if not is_linux or not dpdk_conf.has('RTE_ARCH_X86_64')
         subdir_done()
 endif
 
-if dpdk_conf.get('RTE_IOVA_IN_MBUF') == 0
+if dpdk_conf.get('RTE_IOVA_IN_MBUF') == 0 or not dpdk_conf.has('RTE_LIB_EVENTDEV')
     subdir_done()
 endif