diff mbox

[dpdk-dev] ring: fix compilation error with a broken else clause

Message ID 0d242c92a3734252f6baa5592c56afeba254941b.1517301739.git.gowrishankar.m@linux.vnet.ibm.com (mailing list archive)
State Rejected, archived
Headers

Checks

Context Check Description
ci/checkpatch warning coding style issues
ci/Intel-compilation success Compilation OK

Commit Message

Gowrishankar Jan. 30, 2018, 8:48 a.m. UTC 
  From: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>

Calling rte_smp_wmb macro expands into a compound block, which
would break compiling a else clause following it, if that calling
place has been terminated already with ";", as in below code.
This patch adds { } around this macro to allow compiling else too.

Fixes: git show c9fb3c6289 ("ring: move code in a new header file")

Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
---

Error in compiling source:

In file included from /tmp/dpdk/lib/librte_ring/rte_ring.h:372:0,
                 from /tmp/dpdk/lib/librte_ring/rte_ring.c:90:
/tmp/dpdk/lib/librte_ring/rte_ring_generic.h: In function ‘update_tail’:
/tmp/dpdk/lib/librte_ring/rte_ring_generic.h:75:2: error: ‘else’ without a previous ‘if’
  else
  ^~~~
/tmp/dpdk/mk/internal/rte.compile-pre.mk:114: recipe for target 'rte_ring.o' failed

 lib/librte_ring/rte_ring_generic.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Jerin Jacob Jan. 30, 2018, 8:56 a.m. UTC | #1 
-----Original Message-----
> Date: Tue, 30 Jan 2018 14:18:46 +0530
> From: Gowrishankar <gowrishankar.m@linux.vnet.ibm.com>
> To: dev@dpdk.org
> CC: Olivier Matz <olivier.matz@6wind.com>, thomas@monjalon.net,
>  Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> Subject: [dpdk-dev] [PATCH] ring: fix compilation error with a broken else
>  clause
> X-Mailer: git-send-email 1.9.1
> 
> From: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> 
> Calling rte_smp_wmb macro expands into a compound block, which
> would break compiling a else clause following it, if that calling
> place has been terminated already with ";", as in below code.
> This patch adds { } around this macro to allow compiling else too.
> 
> Fixes: git show c9fb3c6289 ("ring: move code in a new header file")
> 
> Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> ---
> 
> Error in compiling source:
> 
> In file included from /tmp/dpdk/lib/librte_ring/rte_ring.h:372:0,
>                  from /tmp/dpdk/lib/librte_ring/rte_ring.c:90:
> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h: In function ‘update_tail’:
> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h:75:2: error: ‘else’ without a previous ‘if’
>   else
>   ^~~~
> /tmp/dpdk/mk/internal/rte.compile-pre.mk:114: recipe for target 'rte_ring.o' failed
> 
>  lib/librte_ring/rte_ring_generic.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/librte_ring/rte_ring_generic.h b/lib/librte_ring/rte_ring_generic.h
> index 8c3e65b..a668489 100644
> --- a/lib/librte_ring/rte_ring_generic.h
> +++ b/lib/librte_ring/rte_ring_generic.h
> @@ -70,8 +70,9 @@
>  update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
>  		uint32_t single, uint32_t enqueue)
>  {
> -	if (enqueue)
> +	if (enqueue) {

Just wondering, Is it because of rte_smp_wmb() implementation of ppc64 is
not just correct?

We had a similar fix for arm64.
http://dpdk.org/browse/dpdk/commit/?id=59a3cae5305816b3739b4197d277f9455af53b9f


>  		rte_smp_wmb();
> +	}
>  	else
>  		rte_smp_rmb();
>  	/*
> -- 
> 1.9.1
>
Gowrishankar Jan. 30, 2018, 9:09 a.m. UTC | #2 
On Tuesday 30 January 2018 02:26 PM, Jerin Jacob wrote:
> -----Original Message-----
>> Date: Tue, 30 Jan 2018 14:18:46 +0530
>> From: Gowrishankar <gowrishankar.m@linux.vnet.ibm.com>
>> To: dev@dpdk.org
>> CC: Olivier Matz <olivier.matz@6wind.com>, thomas@monjalon.net,
>>   Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
>> Subject: [dpdk-dev] [PATCH] ring: fix compilation error with a broken else
>>   clause
>> X-Mailer: git-send-email 1.9.1
>>
>> From: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
>>
>> Calling rte_smp_wmb macro expands into a compound block, which
>> would break compiling a else clause following it, if that calling
>> place has been terminated already with ";", as in below code.
>> This patch adds { } around this macro to allow compiling else too.
>>
>> Fixes: git show c9fb3c6289 ("ring: move code in a new header file")
>>
>> Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
>> ---
>>
>> Error in compiling source:
>>
>> In file included from /tmp/dpdk/lib/librte_ring/rte_ring.h:372:0,
>>                   from /tmp/dpdk/lib/librte_ring/rte_ring.c:90:
>> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h: In function ‘update_tail’:
>> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h:75:2: error: ‘else’ without a previous ‘if’
>>    else
>>    ^~~~
>> /tmp/dpdk/mk/internal/rte.compile-pre.mk:114: recipe for target 'rte_ring.o' failed
>>
>>   lib/librte_ring/rte_ring_generic.h | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/librte_ring/rte_ring_generic.h b/lib/librte_ring/rte_ring_generic.h
>> index 8c3e65b..a668489 100644
>> --- a/lib/librte_ring/rte_ring_generic.h
>> +++ b/lib/librte_ring/rte_ring_generic.h
>> @@ -70,8 +70,9 @@
>>   update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
>>   		uint32_t single, uint32_t enqueue)
>>   {
>> -	if (enqueue)
>> +	if (enqueue) {
> Just wondering, Is it because of rte_smp_wmb() implementation of ppc64 is
> not just correct?
>
> We had a similar fix for arm64.
> http://dpdk.org/browse/dpdk/commit/?id=59a3cae5305816b3739b4197d277f9455af53b9f
Thanks Jerin. Yes. Similar fix also works. I did not want to touch 
include/ at this time, as it is called at various places in source.
As same problem is seen in arm64, I think it is ok to go with your 
change. If so, I can send version 2 patch with similar change as you showed.

Thanks,
Gowrishankar

>
>>   		rte_smp_wmb();
>> +	}
>>   	else
>>   		rte_smp_rmb();
>>   	/*
>> -- 
>> 1.9.1
>>
Thomas Monjalon Jan. 30, 2018, 9:13 a.m. UTC | #3 
30/01/2018 10:09, gowrishankar muthukrishnan:
> On Tuesday 30 January 2018 02:26 PM, Jerin Jacob wrote:
> > -----Original Message-----
> >> Date: Tue, 30 Jan 2018 14:18:46 +0530
> >> From: Gowrishankar <gowrishankar.m@linux.vnet.ibm.com>
> >> To: dev@dpdk.org
> >> CC: Olivier Matz <olivier.matz@6wind.com>, thomas@monjalon.net,
> >>   Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> >> Subject: [dpdk-dev] [PATCH] ring: fix compilation error with a broken else
> >>   clause
> >> X-Mailer: git-send-email 1.9.1
> >>
> >> From: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> >>
> >> Calling rte_smp_wmb macro expands into a compound block, which
> >> would break compiling a else clause following it, if that calling
> >> place has been terminated already with ";", as in below code.
> >> This patch adds { } around this macro to allow compiling else too.
> >>
> >> Fixes: git show c9fb3c6289 ("ring: move code in a new header file")
> >>
> >> Signed-off-by: Gowrishankar Muthukrishnan <gowrishankar.m@linux.vnet.ibm.com>
> >> ---
> >>
> >> Error in compiling source:
> >>
> >> In file included from /tmp/dpdk/lib/librte_ring/rte_ring.h:372:0,
> >>                   from /tmp/dpdk/lib/librte_ring/rte_ring.c:90:
> >> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h: In function ‘update_tail’:
> >> /tmp/dpdk/lib/librte_ring/rte_ring_generic.h:75:2: error: ‘else’ without a previous ‘if’
> >>    else
> >>    ^~~~
> >> /tmp/dpdk/mk/internal/rte.compile-pre.mk:114: recipe for target 'rte_ring.o' failed
> >>
> >>   lib/librte_ring/rte_ring_generic.h | 3 ++-
> >>   1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/lib/librte_ring/rte_ring_generic.h b/lib/librte_ring/rte_ring_generic.h
> >> index 8c3e65b..a668489 100644
> >> --- a/lib/librte_ring/rte_ring_generic.h
> >> +++ b/lib/librte_ring/rte_ring_generic.h
> >> @@ -70,8 +70,9 @@
> >>   update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
> >>   		uint32_t single, uint32_t enqueue)
> >>   {
> >> -	if (enqueue)
> >> +	if (enqueue) {
> > Just wondering, Is it because of rte_smp_wmb() implementation of ppc64 is
> > not just correct?
> >
> > We had a similar fix for arm64.
> > http://dpdk.org/browse/dpdk/commit/?id=59a3cae5305816b3739b4197d277f9455af53b9f
> Thanks Jerin. Yes. Similar fix also works. I did not want to touch 
> include/ at this time, as it is called at various places in source.
> As same problem is seen in arm64, I think it is ok to go with your 
> change. If so, I can send version 2 patch with similar change as you showed.

Please send a patch for the fix in atomics.
diff mbox

Patch

diff --git a/lib/librte_ring/rte_ring_generic.h b/lib/librte_ring/rte_ring_generic.h
index 8c3e65b..a668489 100644
--- a/lib/librte_ring/rte_ring_generic.h
+++ b/lib/librte_ring/rte_ring_generic.h
@@ -70,8 +70,9 @@ 
 update_tail(struct rte_ring_headtail *ht, uint32_t old_val, uint32_t new_val,
 		uint32_t single, uint32_t enqueue)
 {
-	if (enqueue)
+	if (enqueue) {
 		rte_smp_wmb();
+	}
 	else
 		rte_smp_rmb();
 	/*