Re: [PATCH BUGFIX] block, bfq: update wr_busy_queues if needed on a queue split

[Paolo Valente]

> Il giorno 19 giu 2017, alle ore 09:38, kbuild test robot  ha 
> scritto:
> 
> Hi Paolo,
> 
> [auto build test WARNING on v4.12-rc5]
> [also build test WARNING on next-20170616]
> [cannot apply to block/for-next]
> [if your patch is applied to the wrong git tree, please drop us a note to 
> help improve the system]
> 
> url:
> https://github.com/0day-ci/linux/commits/Paolo-Valente/block-bfq-update-wr_busy_queues-if-needed-on-a-queue-split/20170619-145003
> config: i386-randconfig-x000-201725 (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
># save the attached .config to linux build tree
>make ARCH=i386 
> 
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
> 
> All warnings (new ones prefixed by >>):
> 
>   block/bfq-iosched.c: In function 'bfq_get_rq_private':
>>> block/bfq-iosched.c:770:10: warning: 'old_wr_coeff' may be used 
>>> uninitialized in this function [-Wmaybe-uninitialized]
> else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
> ^
>   block/bfq-iosched.c:731:15: note: 'old_wr_coeff' was declared here
> unsigned int old_wr_coeff;
>  ^~~~
> 

I'm sending a V2, (probably imperceptibly) slower on average, but not
confusing the compiler.

Thanks,
Paolo

> vim +/old_wr_coeff +770 block/bfq-iosched.c
> 
>   754 time_is_before_jiffies(bfqq->last_wr_start_finish +
>   755bfqq->wr_cur_max_time))) {
>   756 bfq_log_bfqq(bfqq->bfqd, bfqq,
>   757 "resume state: switching off wr");
>   758 
>   759 bfqq->wr_coeff = 1;
>   760 }
>   761 
>   762 /* make sure weight will be updated, however we got here */
>   763 bfqq->entity.prio_changed = 1;
>   764 
>   765 if (likely(!busy))
>   766 return;
>   767 
>   768 if (old_wr_coeff == 1 && bfqq->wr_coeff > 1)
>   769 bfqd->wr_busy_queues++;
>> 770  else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
>   771 bfqd->wr_busy_queues--;
>   772 }
>   773 
>   774 static int bfqq_process_refs(struct bfq_queue *bfqq)
>   775 {
>   776 return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
>   777 }
>   778 
> 
> ---
> 0-DAY kernel test infrastructureOpen Source Technology Center
> https://lists.01.org/pipermail/kbuild-all   Intel Corporation
> <.config.gz>

Re: [PATCH BUGFIX] block, bfq: update wr_busy_queues if needed on a queue split

[Paolo Valente]

> Il giorno 19 giu 2017, alle ore 09:38, kbuild test robot  ha 
> scritto:
> 
> Hi Paolo,
> 
> [auto build test WARNING on v4.12-rc5]
> [also build test WARNING on next-20170616]
> [cannot apply to block/for-next]
> [if your patch is applied to the wrong git tree, please drop us a note to 
> help improve the system]
> 
> url:
> https://github.com/0day-ci/linux/commits/Paolo-Valente/block-bfq-update-wr_busy_queues-if-needed-on-a-queue-split/20170619-145003
> config: i386-randconfig-x000-201725 (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
># save the attached .config to linux build tree
>make ARCH=i386 
> 
> Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
> http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
> 
> All warnings (new ones prefixed by >>):
> 
>   block/bfq-iosched.c: In function 'bfq_get_rq_private':
>>> block/bfq-iosched.c:770:10: warning: 'old_wr_coeff' may be used 
>>> uninitialized in this function [-Wmaybe-uninitialized]
> else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
> ^
>   block/bfq-iosched.c:731:15: note: 'old_wr_coeff' was declared here
> unsigned int old_wr_coeff;
>  ^~~~
> 

I'm sending a V2, (probably imperceptibly) slower on average, but not
confusing the compiler.

Thanks,
Paolo

> vim +/old_wr_coeff +770 block/bfq-iosched.c
> 
>   754 time_is_before_jiffies(bfqq->last_wr_start_finish +
>   755bfqq->wr_cur_max_time))) {
>   756 bfq_log_bfqq(bfqq->bfqd, bfqq,
>   757 "resume state: switching off wr");
>   758 
>   759 bfqq->wr_coeff = 1;
>   760 }
>   761 
>   762 /* make sure weight will be updated, however we got here */
>   763 bfqq->entity.prio_changed = 1;
>   764 
>   765 if (likely(!busy))
>   766 return;
>   767 
>   768 if (old_wr_coeff == 1 && bfqq->wr_coeff > 1)
>   769 bfqd->wr_busy_queues++;
>> 770  else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
>   771 bfqd->wr_busy_queues--;
>   772 }
>   773 
>   774 static int bfqq_process_refs(struct bfq_queue *bfqq)
>   775 {
>   776 return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
>   777 }
>   778 
> 
> ---
> 0-DAY kernel test infrastructureOpen Source Technology Center
> https://lists.01.org/pipermail/kbuild-all   Intel Corporation
> <.config.gz>

Re: [PATCH BUGFIX] block, bfq: update wr_busy_queues if needed on a queue split

[kbuild test robot]

Hi Paolo,

[auto build test WARNING on v4.12-rc5]
[also build test WARNING on next-20170616]
[cannot apply to block/for-next]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Paolo-Valente/block-bfq-update-wr_busy_queues-if-needed-on-a-queue-split/20170619-145003
config: i386-randconfig-x000-201725 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=i386 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   block/bfq-iosched.c: In function 'bfq_get_rq_private':
>> block/bfq-iosched.c:770:10: warning: 'old_wr_coeff' may be used 
>> uninitialized in this function [-Wmaybe-uninitialized]
 else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
 ^
   block/bfq-iosched.c:731:15: note: 'old_wr_coeff' was declared here
 unsigned int old_wr_coeff;
  ^~~~

vim +/old_wr_coeff +770 block/bfq-iosched.c

   754  time_is_before_jiffies(bfqq->last_wr_start_finish +
   755 bfqq->wr_cur_max_time))) {
   756  bfq_log_bfqq(bfqq->bfqd, bfqq,
   757  "resume state: switching off wr");
   758  
   759  bfqq->wr_coeff = 1;
   760  }
   761  
   762  /* make sure weight will be updated, however we got here */
   763  bfqq->entity.prio_changed = 1;
   764  
   765  if (likely(!busy))
   766  return;
   767  
   768  if (old_wr_coeff == 1 && bfqq->wr_coeff > 1)
   769  bfqd->wr_busy_queues++;
 > 770  else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
   771  bfqd->wr_busy_queues--;
   772  }
   773  
   774  static int bfqq_process_refs(struct bfq_queue *bfqq)
   775  {
   776  return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
   777  }
   778  

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip

Re: [PATCH BUGFIX] block, bfq: update wr_busy_queues if needed on a queue split

[kbuild test robot]

Hi Paolo,

[auto build test WARNING on v4.12-rc5]
[also build test WARNING on next-20170616]
[cannot apply to block/for-next]
[if your patch is applied to the wrong git tree, please drop us a note to help 
improve the system]

url:
https://github.com/0day-ci/linux/commits/Paolo-Valente/block-bfq-update-wr_busy_queues-if-needed-on-a-queue-split/20170619-145003
config: i386-randconfig-x000-201725 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=i386 

Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings

All warnings (new ones prefixed by >>):

   block/bfq-iosched.c: In function 'bfq_get_rq_private':
>> block/bfq-iosched.c:770:10: warning: 'old_wr_coeff' may be used 
>> uninitialized in this function [-Wmaybe-uninitialized]
 else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
 ^
   block/bfq-iosched.c:731:15: note: 'old_wr_coeff' was declared here
 unsigned int old_wr_coeff;
  ^~~~

vim +/old_wr_coeff +770 block/bfq-iosched.c

   754  time_is_before_jiffies(bfqq->last_wr_start_finish +
   755 bfqq->wr_cur_max_time))) {
   756  bfq_log_bfqq(bfqq->bfqd, bfqq,
   757  "resume state: switching off wr");
   758  
   759  bfqq->wr_coeff = 1;
   760  }
   761  
   762  /* make sure weight will be updated, however we got here */
   763  bfqq->entity.prio_changed = 1;
   764  
   765  if (likely(!busy))
   766  return;
   767  
   768  if (old_wr_coeff == 1 && bfqq->wr_coeff > 1)
   769  bfqd->wr_busy_queues++;
 > 770  else if (old_wr_coeff > 1 && bfqq->wr_coeff == 1)
   771  bfqd->wr_busy_queues--;
   772  }
   773  
   774  static int bfqq_process_refs(struct bfq_queue *bfqq)
   775  {
   776  return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
   777  }
   778  

---
0-DAY kernel test infrastructureOpen Source Technology Center
https://lists.01.org/pipermail/kbuild-all   Intel Corporation


.config.gz
Description: application/gzip