[dpdk-dev] [PATCH] service: clean references to removed symbol

[dpdk-dev] [PATCH] service: clean references to removed symbol

[David Marchand]

rte_service_get_id() was removed in v17.11 but the API description
still referenced it and a version node was still present in EAL map.

Fixes: 8edc9aaaf217 ("service: use id in get by name function")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/librte_eal/include/rte_service.h | 5 +----
 lib/librte_eal/version.map           | 1 -
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/lib/librte_eal/include/rte_service.h b/lib/librte_eal/include/rte_service.h
index ca9950d091..c7d037d862 100644
--- a/lib/librte_eal/include/rte_service.h
+++ b/lib/librte_eal/include/rte_service.h
@@ -47,10 +47,7 @@ extern "C" {
 #define RTE_SERVICE_CAP_MT_SAFE (1 << 0)
 
 /**
- *  Return the number of services registered.
- *
- * The number of services registered can be passed to *rte_service_get_by_id*,
- * enabling the application to retrieve the specification of each service.
+ * Return the number of services registered.
  *
  * @return The number of services registered.
  */
diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
index e23745ae6e..0f2a9228b3 100644
--- a/lib/librte_eal/version.map
+++ b/lib/librte_eal/version.map
@@ -159,7 +159,6 @@ DPDK_21 {
 	rte_service_component_unregister;
 	rte_service_dump;
 	rte_service_finalize;
-	rte_service_get_by_id;
 	rte_service_get_by_name;
 	rte_service_get_count;
 	rte_service_get_name;
-- 
2.23.0

Re: [dpdk-dev] [PATCH] service: clean references to removed symbol

[Van Haaren, Harry]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Wednesday, April 7, 2021 10:07 AM
> To: dev@dpdk.org
> Cc: stable@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>; Ray
> Kinsella <mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com>; Pavan
> Nikhilesh <pbhagavatula@caviumnetworks.com>
> Subject: [PATCH] service: clean references to removed symbol
> 
> rte_service_get_id() was removed in v17.11 but the API description
> still referenced it and a version node was still present in EAL map.
> 
> Fixes: 8edc9aaaf217 ("service: use id in get by name function")
> Cc: stable@dpdk.org
> 
> Signed-off-by: David Marchand <david.marchand@redhat.com>

For rte_service.h doc changes I'm all fine.

For ABI consistency, this removes a function from the DPDK_21 version map that didn't exist in
the shared object itself. I'm not sure if that's an ABI break or not... I see ABI experts on CC,
and will let them comment on that topic.

Reviewed-by: Harry van Haaren <harry.van.haaren@intel.com>

> ---
>  lib/librte_eal/include/rte_service.h | 5 +----
>  lib/librte_eal/version.map           | 1 -
>  2 files changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/lib/librte_eal/include/rte_service.h
> b/lib/librte_eal/include/rte_service.h
> index ca9950d091..c7d037d862 100644
> --- a/lib/librte_eal/include/rte_service.h
> +++ b/lib/librte_eal/include/rte_service.h
> @@ -47,10 +47,7 @@ extern "C" {
>  #define RTE_SERVICE_CAP_MT_SAFE (1 << 0)
> 
>  /**
> - *  Return the number of services registered.
> - *
> - * The number of services registered can be passed to *rte_service_get_by_id*,
> - * enabling the application to retrieve the specification of each service.
> + * Return the number of services registered.
>   *
>   * @return The number of services registered.
>   */
> diff --git a/lib/librte_eal/version.map b/lib/librte_eal/version.map
> index e23745ae6e..0f2a9228b3 100644
> --- a/lib/librte_eal/version.map
> +++ b/lib/librte_eal/version.map
> @@ -159,7 +159,6 @@ DPDK_21 {
>  	rte_service_component_unregister;
>  	rte_service_dump;
>  	rte_service_finalize;
> -	rte_service_get_by_id;
>  	rte_service_get_by_name;
>  	rte_service_get_count;
>  	rte_service_get_name;
> --
> 2.23.0

Re: [dpdk-dev] [PATCH] service: clean references to removed symbol

[David Marchand]

On Thu, Apr 8, 2021 at 2:54 PM Van Haaren, Harry
<harry.van.haaren@intel.com> wrote:
>
> > -----Original Message-----
> > From: David Marchand <david.marchand@redhat.com>
> > Sent: Wednesday, April 7, 2021 10:07 AM
> > To: dev@dpdk.org
> > Cc: stable@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>; Ray
> > Kinsella <mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com>; Pavan
> > Nikhilesh <pbhagavatula@caviumnetworks.com>
> > Subject: [PATCH] service: clean references to removed symbol
> >
> > rte_service_get_id() was removed in v17.11 but the API description
> > still referenced it and a version node was still present in EAL map.
> >
> > Fixes: 8edc9aaaf217 ("service: use id in get by name function")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: David Marchand <david.marchand@redhat.com>
>
> For rte_service.h doc changes I'm all fine.
>
> For ABI consistency, this removes a function from the DPDK_21 version map that didn't exist in
> the shared object itself. I'm not sure if that's an ABI break or not... I see ABI experts on CC,
> and will let them comment on that topic.

The symbol is not in the API anymore.
Applications can't have a reference to this symbol without a definition.


-- 
David Marchand

Re: [dpdk-dev] [PATCH] service: clean references to removed symbol

[Van Haaren, Harry]

> -----Original Message-----
> From: David Marchand <david.marchand@redhat.com>
> Sent: Thursday, April 8, 2021 1:58 PM
> To: Van Haaren, Harry <harry.van.haaren@intel.com>
> Cc: dev@dpdk.org; stable@dpdk.org; Ray Kinsella <mdr@ashroe.eu>; Neil Horman
> <nhorman@tuxdriver.com>; Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>
> Subject: Re: [PATCH] service: clean references to removed symbol
> 
> On Thu, Apr 8, 2021 at 2:54 PM Van Haaren, Harry
> <harry.van.haaren@intel.com> wrote:
> >
> > > -----Original Message-----
> > > From: David Marchand <david.marchand@redhat.com>
> > > Sent: Wednesday, April 7, 2021 10:07 AM
> > > To: dev@dpdk.org
> > > Cc: stable@dpdk.org; Van Haaren, Harry <harry.van.haaren@intel.com>; Ray
> > > Kinsella <mdr@ashroe.eu>; Neil Horman <nhorman@tuxdriver.com>; Pavan
> > > Nikhilesh <pbhagavatula@caviumnetworks.com>
> > > Subject: [PATCH] service: clean references to removed symbol
> > >
> > > rte_service_get_id() was removed in v17.11 but the API description
> > > still referenced it and a version node was still present in EAL map.
> > >
> > > Fixes: 8edc9aaaf217 ("service: use id in get by name function")
> > > Cc: stable@dpdk.org
> > >
> > > Signed-off-by: David Marchand <david.marchand@redhat.com>
> >
> > For rte_service.h doc changes I'm all fine.
> >
> > For ABI consistency, this removes a function from the DPDK_21 version map that
> didn't exist in
> > the shared object itself. I'm not sure if that's an ABI break or not... I see ABI
> experts on CC,
> > and will let them comment on that topic.
> 
> The symbol is not in the API anymore.
> Applications can't have a reference to this symbol without a definition.

Agreed, however I'm not familiar enough with linking/ABI stability to
know if removing a symbol (even when not available in the API) could
affect the resulting shared object's ABI.

If somebody says there's no risk in ABI break, go ahead and merge. -Harry

Re: [dpdk-dev] [PATCH] service: clean references to removed symbol

[David Marchand]

On Thu, Apr 8, 2021 at 3:08 PM Van Haaren, Harry
<harry.van.haaren@intel.com> wrote:
> > > For rte_service.h doc changes I'm all fine.
> > >
> > > For ABI consistency, this removes a function from the DPDK_21 version map that
> > didn't exist in
> > > the shared object itself. I'm not sure if that's an ABI break or not... I see ABI
> > experts on CC,
> > > and will let them comment on that topic.
> >
> > The symbol is not in the API anymore.
> > Applications can't have a reference to this symbol without a definition.
>
> Agreed, however I'm not familiar enough with linking/ABI stability to
> know if removing a symbol (even when not available in the API) could
> affect the resulting shared object's ABI.

After a discussion with Dodji and looking at binutils, I understand
that the versioning is applied for each symbol found in an elf object.
So at least with binutils, non-existent nodes in a version script are
harmless and have no impact on the generated elf.


-- 
David Marchand

Re: [dpdk-dev] [PATCH] service: clean references to removed symbol

[Thomas Monjalon]

08/04/2021 16:04, David Marchand:
> On Thu, Apr 8, 2021 at 3:08 PM Van Haaren, Harry
> <harry.van.haaren@intel.com> wrote:
> > > > For rte_service.h doc changes I'm all fine.
> > > >
> > > > For ABI consistency, this removes a function from the DPDK_21 version map that
> > > didn't exist in
> > > > the shared object itself. I'm not sure if that's an ABI break or not... I see ABI
> > > experts on CC,
> > > > and will let them comment on that topic.
> > >
> > > The symbol is not in the API anymore.
> > > Applications can't have a reference to this symbol without a definition.
> >
> > Agreed, however I'm not familiar enough with linking/ABI stability to
> > know if removing a symbol (even when not available in the API) could
> > affect the resulting shared object's ABI.
> 
> After a discussion with Dodji and looking at binutils, I understand
> that the versioning is applied for each symbol found in an elf object.
> So at least with binutils, non-existent nodes in a version script are
> harmless and have no impact on the generated elf.

Yes I don't see how it could break ABI.

Acked-by: Thomas Monjalon <thomas@monjalon.net>

Re: [dpdk-dev] [dpdk-stable] [PATCH] service: clean references to removed symbol

[David Marchand]

On Wed, Apr 7, 2021 at 11:08 AM David Marchand
<david.marchand@redhat.com> wrote:
>
> rte_service_get_id() was removed in v17.11 but the API description
> still referenced it and a version node was still present in EAL map.
>
> Fixes: 8edc9aaaf217 ("service: use id in get by name function")
> Cc: stable@dpdk.org
>
> Signed-off-by: David Marchand <david.marchand@redhat.com>

Reviewed-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>

Applied, thanks.

-- 
David Marchand