[tip: core/rcu] rcuperf: Add ability to increase object allocation size

[tip: core/rcu] rcuperf: Add ability to increase object allocation size

[tip-bot2 for Joel Fernandes (Google)]

The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     f87dc808009ac86c790031627698ef1a34c31e25
Gitweb:        https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25
Author:        Joel Fernandes (Google) <joel@joelfernandes.org>
AuthorDate:    Mon, 16 Mar 2020 12:32:26 -04:00
Committer:     Paul E. McKenney <paulmck@kernel.org>
CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00

rcuperf: Add ability to increase object allocation size

This allows us to increase memory pressure dynamically using a new
rcuperf boot command line parameter called 'rcumult'.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
 kernel/rcu/rcuperf.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index a4a8d09..16dd1e6 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -88,6 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
 torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
+torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
 
 static char *perf_type = "rcu";
 module_param(perf_type, charp, 0444);
@@ -635,7 +636,7 @@ kfree_perf_thread(void *arg)
 		}
 
 		for (i = 0; i < kfree_alloc_num; i++) {
-			alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
+			alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
 			if (!alloc_ptr)
 				return -ENOMEM;
 
@@ -722,6 +723,8 @@ kfree_perf_init(void)
 		schedule_timeout_uninterruptible(1);
 	}
 
+	pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
+
 	kfree_reader_tasks = kcalloc(kfree_nrealthreads, sizeof(kfree_reader_tasks[0]),
 			       GFP_KERNEL);
 	if (kfree_reader_tasks == NULL) {

[PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Ingo Molnar]

* tip-bot2 for Joel Fernandes (Google) <tip-bot2@linutronix.de> wrote:

> The following commit has been merged into the core/rcu branch of tip:
> 
> Commit-ID:     f87dc808009ac86c790031627698ef1a34c31e25
> Gitweb:        https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25
> Author:        Joel Fernandes (Google) <joel@joelfernandes.org>
> AuthorDate:    Mon, 16 Mar 2020 12:32:26 -04:00
> Committer:     Paul E. McKenney <paulmck@kernel.org>
> CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00
> 
> rcuperf: Add ability to increase object allocation size
> 
> This allows us to increase memory pressure dynamically using a new
> rcuperf boot command line parameter called 'rcumult'.
> 
> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> ---
>  kernel/rcu/rcuperf.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> index a4a8d09..16dd1e6 100644
> --- a/kernel/rcu/rcuperf.c
> +++ b/kernel/rcu/rcuperf.c
> @@ -88,6 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
>  torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
>  torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
>  torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
> +torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
>  
>  static char *perf_type = "rcu";
>  module_param(perf_type, charp, 0444);
> @@ -635,7 +636,7 @@ kfree_perf_thread(void *arg)
>  		}
>  
>  		for (i = 0; i < kfree_alloc_num; i++) {
> -			alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
> +			alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
>  			if (!alloc_ptr)
>  				return -ENOMEM;
>  
> @@ -722,6 +723,8 @@ kfree_perf_init(void)
>  		schedule_timeout_uninterruptible(1);
>  	}
>  
> +	pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));

There's a new build warning on certain 32-bit kernel builds due to 
this commit:

In file included from ./include/linux/printk.h:7,
                 from ./include/linux/kernel.h:15,
                 from kernel/rcu/rcuperf.c:13:
kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]
    5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
      |                  ^~~~~~
./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
    9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
      |                    ^~~~~~~~
./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
  295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
      |         ^~~~~~~~~~
kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
  726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
      |  ^~~~~~~~
kernel/rcu/rcuperf.c:726:32: note: format string is defined here
  726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
      |                              ~~^
      |                                |
      |                                long unsigned int
      |                              %u


The reason for the warning is that both kfree_mult and sizeof() are 
'int' types on 32-bit kernels, while the format string expects a long.

Instead of casting the type to long or tweaking the format string, the 
most straightforward solution is to upgrade kfree_mult to a long. 
Since this depends on CONFIG_RCU_PERF_TEST

BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
mistakenly believe that it's somehow related to perf, while it isn't. =B-)

Thanks,

	Ingo

Signed-off-by: Ingo Molnar <mingo@kernel.org>

 kernel/rcu/rcuperf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index 16dd1e6b7c09..221a0a3810e4 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -88,7 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
 torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
-torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
+torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
 
 static char *perf_type = "rcu";
 module_param(perf_type, charp, 0444);

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Paul E. McKenney]

On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> 
> * tip-bot2 for Joel Fernandes (Google) <tip-bot2@linutronix.de> wrote:
> 
> > The following commit has been merged into the core/rcu branch of tip:
> > 
> > Commit-ID:     f87dc808009ac86c790031627698ef1a34c31e25
> > Gitweb:        https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25
> > Author:        Joel Fernandes (Google) <joel@joelfernandes.org>
> > AuthorDate:    Mon, 16 Mar 2020 12:32:26 -04:00
> > Committer:     Paul E. McKenney <paulmck@kernel.org>
> > CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00
> > 
> > rcuperf: Add ability to increase object allocation size
> > 
> > This allows us to increase memory pressure dynamically using a new
> > rcuperf boot command line parameter called 'rcumult'.
> > 
> > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> > ---
> >  kernel/rcu/rcuperf.c | 5 ++++-
> >  1 file changed, 4 insertions(+), 1 deletion(-)
> > 
> > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> > index a4a8d09..16dd1e6 100644
> > --- a/kernel/rcu/rcuperf.c
> > +++ b/kernel/rcu/rcuperf.c
> > @@ -88,6 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
> >  torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
> >  torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
> >  torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
> > +torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
> >  
> >  static char *perf_type = "rcu";
> >  module_param(perf_type, charp, 0444);
> > @@ -635,7 +636,7 @@ kfree_perf_thread(void *arg)
> >  		}
> >  
> >  		for (i = 0; i < kfree_alloc_num; i++) {
> > -			alloc_ptr = kmalloc(sizeof(struct kfree_obj), GFP_KERNEL);
> > +			alloc_ptr = kmalloc(kfree_mult * sizeof(struct kfree_obj), GFP_KERNEL);
> >  			if (!alloc_ptr)
> >  				return -ENOMEM;
> >  
> > @@ -722,6 +723,8 @@ kfree_perf_init(void)
> >  		schedule_timeout_uninterruptible(1);
> >  	}
> >  
> > +	pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> 
> There's a new build warning on certain 32-bit kernel builds due to 
> this commit:
> 
> In file included from ./include/linux/printk.h:7,
>                  from ./include/linux/kernel.h:15,
>                  from kernel/rcu/rcuperf.c:13:
> kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
> ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]
>     5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
>       |                  ^~~~~~
> ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
>     9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
>       |                    ^~~~~~~~
> ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
>   295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
>       |         ^~~~~~~~~~
> kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
>   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
>       |  ^~~~~~~~
> kernel/rcu/rcuperf.c:726:32: note: format string is defined here
>   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
>       |                              ~~^
>       |                                |
>       |                                long unsigned int
>       |                              %u
> 
> 
> The reason for the warning is that both kfree_mult and sizeof() are 
> 'int' types on 32-bit kernels, while the format string expects a long.
> 
> Instead of casting the type to long or tweaking the format string, the 
> most straightforward solution is to upgrade kfree_mult to a long. 
> Since this depends on CONFIG_RCU_PERF_TEST

Makes sense, and I have queued the patch below, which I am assuming
that you want in the upcoming merge window.  If you don't tell me
otherwise, I will send you an urgent pull request later today.
Or, if you just put it directly into -tip yourself:

Reviewed-by: Paul E. McKenney <paulmck@kernel.org>

Either way, please let me know.

> BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> mistakenly believe that it's somehow related to perf, while it isn't. =B-)

Fair enough, especially given that perf was there first and is also way
more heavily used.  ;-)

But I am guessing that this one is OK for the v5.9 merge window.
Either way, I will update as you say.

							Thanx, Paul

------------------------------------------------------------------------

commit 2fbc7d67a2ed108e3ac63296670fecb3a42fddd0
Author: Ingo Molnar <mingo@kernel.org>
Date:   Tue May 26 12:10:01 2020 -0700

    rcuperf: Fix kfree_mult to match printk() format
    
    This commit changes the type of kfree_mult from int to long in order
    to match the printk() format on 32-bit systems.
    
    Reported-by: kbuild test robot <lkp@intel.com>
    Signed-off-by: Ingo Molnar <mingo@kernel.org>
    Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
index d906ca9..fb3a1f0 100644
--- a/kernel/rcu/rcuperf.c
+++ b/kernel/rcu/rcuperf.c
@@ -93,7 +93,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
 torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
 torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
 torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
-torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
+torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
 
 static char *perf_type = "rcu";
 module_param(perf_type, charp, 0444);

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Joel Fernandes]

On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
[...]
> ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument
> of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’
> [-Wformat=] 5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */ |
> ^~~~~~
> ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
>     9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
>       |                    ^~~~~~~~
> ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
>   295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
>       |         ^~~~~~~~~~
> kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
>   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
>       |  ^~~~~~~~
> kernel/rcu/rcuperf.c:726:32: note: format string is defined here
>   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
>       |                              ~~^
>       |                                |
>       |                                long unsigned int
>       |                              %u
> 
> 
> The reason for the warning is that both kfree_mult and sizeof() are 
> 'int' types on 32-bit kernels, while the format string expects a long.
> 
> Instead of casting the type to long or tweaking the format string, the 
> most straightforward solution is to upgrade kfree_mult to a long. 
> Since this depends on CONFIG_RCU_PERF_TEST

Thanks for fixing it.

> BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> mistakenly believe that it's somehow related to perf, while it isn't. =B-)

Would it be better to call it 'RCUPERF_TEST' instead of the
'RCU_PERFORMANCE_TEST' you are proposing? I feel the word 'PERFORMANCE' is
too long.  Also, 'rcuperf test' instead of the 'rcu performance test' you are
proposing.  I am Ok with doing it however you and Paul want it though, let me
know.

Paul, should I send you a renaming patch for the new performance tests as
well (which I believe should be in the -dev branch).

thanks,

 - Joel


> 
> Thanks,
> 
> 	Ingo
> 
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> 
>  kernel/rcu/rcuperf.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> index 16dd1e6b7c09..221a0a3810e4 100644
> --- a/kernel/rcu/rcuperf.c
> +++ b/kernel/rcu/rcuperf.c
> @@ -88,7 +88,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
>  torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
>  torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
>  torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
> -torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
> +torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
>  
>  static char *perf_type = "rcu";
>  module_param(perf_type, charp, 0444);

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Geert Uytterhoeven]

Hi Paul,

On Tue, May 26, 2020 at 9:17 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> > * tip-bot2 for Joel Fernandes (Google) <tip-bot2@linutronix.de> wrote:
> >
> > > The following commit has been merged into the core/rcu branch of tip:
> > >
> > > Commit-ID:     f87dc808009ac86c790031627698ef1a34c31e25
> > > Gitweb:        https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25
> > > Author:        Joel Fernandes (Google) <joel@joelfernandes.org>
> > > AuthorDate:    Mon, 16 Mar 2020 12:32:26 -04:00
> > > Committer:     Paul E. McKenney <paulmck@kernel.org>
> > > CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00
> > >
> > > rcuperf: Add ability to increase object allocation size
> > >
> > > This allows us to increase memory pressure dynamically using a new
> > > rcuperf boot command line parameter called 'rcumult'.
> > >
> > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> > > ---
> > >  kernel/rcu/rcuperf.c | 5 ++++-
> > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> > > index a4a8d09..16dd1e6 100644
> > > --- a/kernel/rcu/rcuperf.c
> > > +++ b/kernel/rcu/rcuperf.c

> > > @@ -722,6 +723,8 @@ kfree_perf_init(void)
> > >             schedule_timeout_uninterruptible(1);
> > >     }
> > >
> > > +   pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> >
> > There's a new build warning on certain 32-bit kernel builds due to
> > this commit:
> >
> > In file included from ./include/linux/printk.h:7,
> >                  from ./include/linux/kernel.h:15,
> >                  from kernel/rcu/rcuperf.c:13:
> > kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
> > ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]
> >     5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
> >       |                  ^~~~~~
> > ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
> >     9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
> >       |                    ^~~~~~~~
> > ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
> >   295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> >       |         ^~~~~~~~~~
> > kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
> >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> >       |  ^~~~~~~~
> > kernel/rcu/rcuperf.c:726:32: note: format string is defined here
> >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> >       |                              ~~^
> >       |                                |
> >       |                                long unsigned int
> >       |                              %u

This issue is now upstream.

> > The reason for the warning is that both kfree_mult and sizeof() are
> > 'int' types on 32-bit kernels, while the format string expects a long.

sizeof() is of type size_t, which is either unsigned int (32-bit) or
unsigned long (64-bit).
Hence the result of the multiplication is also of type size_t.

> >
> > Instead of casting the type to long or tweaking the format string, the
> > most straightforward solution is to upgrade kfree_mult to a long.
> > Since this depends on CONFIG_RCU_PERF_TEST

So the proper fix is Kefeng's patch from April:
"[PATCH -next] rcuperf: Fix printk format warning"
https://lore.kernel.org/r/20200417040245.66382-1-wangkefeng.wang@huawei.com

":"--
> Makes sense, and I have queued the patch below, which I am assuming
> that you want in the upcoming merge window.  If you don't tell me
> otherwise, I will send you an urgent pull request later today.
> Or, if you just put it directly into -tip yourself:
>
> Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
>
> Either way, please let me know.
>
> > BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> > to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> > mistakenly believe that it's somehow related to perf, while it isn't. =B-)
>
> Fair enough, especially given that perf was there first and is also way
> more heavily used.  ;-)
>
> But I am guessing that this one is OK for the v5.9 merge window.
> Either way, I will update as you say.
>
>                                                         Thanx, Paul
>
> ------------------------------------------------------------------------
>
> commit 2fbc7d67a2ed108e3ac63296670fecb3a42fddd0
> Author: Ingo Molnar <mingo@kernel.org>
> Date:   Tue May 26 12:10:01 2020 -0700
>
>     rcuperf: Fix kfree_mult to match printk() format
>
>     This commit changes the type of kfree_mult from int to long in order
>     to match the printk() format on 32-bit systems.
>
>     Reported-by: kbuild test robot <lkp@intel.com>
>     Signed-off-by: Ingo Molnar <mingo@kernel.org>
>     Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
>
> diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> index d906ca9..fb3a1f0 100644
> --- a/kernel/rcu/rcuperf.c
> +++ b/kernel/rcu/rcuperf.c
> @@ -93,7 +93,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
>  torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
>  torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
>  torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
> -torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
> +torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
>
>  static char *perf_type = "rcu";
>  module_param(perf_type, charp, 0444);

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Paul E. McKenney]

On Tue, Jun 02, 2020 at 11:57:51AM +0200, Geert Uytterhoeven wrote:
> Hi Paul,
> 
> On Tue, May 26, 2020 at 9:17 PM Paul E. McKenney <paulmck@kernel.org> wrote:
> > On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> > > * tip-bot2 for Joel Fernandes (Google) <tip-bot2@linutronix.de> wrote:
> > >
> > > > The following commit has been merged into the core/rcu branch of tip:
> > > >
> > > > Commit-ID:     f87dc808009ac86c790031627698ef1a34c31e25
> > > > Gitweb:        https://git.kernel.org/tip/f87dc808009ac86c790031627698ef1a34c31e25
> > > > Author:        Joel Fernandes (Google) <joel@joelfernandes.org>
> > > > AuthorDate:    Mon, 16 Mar 2020 12:32:26 -04:00
> > > > Committer:     Paul E. McKenney <paulmck@kernel.org>
> > > > CommitterDate: Mon, 27 Apr 2020 11:02:50 -07:00
> > > >
> > > > rcuperf: Add ability to increase object allocation size
> > > >
> > > > This allows us to increase memory pressure dynamically using a new
> > > > rcuperf boot command line parameter called 'rcumult'.
> > > >
> > > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> > > > Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> > > > ---
> > > >  kernel/rcu/rcuperf.c | 5 ++++-
> > > >  1 file changed, 4 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> > > > index a4a8d09..16dd1e6 100644
> > > > --- a/kernel/rcu/rcuperf.c
> > > > +++ b/kernel/rcu/rcuperf.c
> 
> > > > @@ -722,6 +723,8 @@ kfree_perf_init(void)
> > > >             schedule_timeout_uninterruptible(1);
> > > >     }
> > > >
> > > > +   pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> > >
> > > There's a new build warning on certain 32-bit kernel builds due to
> > > this commit:
> > >
> > > In file included from ./include/linux/printk.h:7,
> > >                  from ./include/linux/kernel.h:15,
> > >                  from kernel/rcu/rcuperf.c:13:
> > > kernel/rcu/rcuperf.c: In function ‘kfree_perf_init’:
> > > ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’ [-Wformat=]
> > >     5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */
> > >       |                  ^~~~~~
> > > ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
> > >     9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
> > >       |                    ^~~~~~~~
> > > ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
> > >   295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> > >       |         ^~~~~~~~~~
> > > kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
> > >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> > >       |  ^~~~~~~~
> > > kernel/rcu/rcuperf.c:726:32: note: format string is defined here
> > >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> > >       |                              ~~^
> > >       |                                |
> > >       |                                long unsigned int
> > >       |                              %u
> 
> This issue is now upstream.
> 
> > > The reason for the warning is that both kfree_mult and sizeof() are
> > > 'int' types on 32-bit kernels, while the format string expects a long.
> 
> sizeof() is of type size_t, which is either unsigned int (32-bit) or
> unsigned long (64-bit).
> Hence the result of the multiplication is also of type size_t.
> 
> > >
> > > Instead of casting the type to long or tweaking the format string, the
> > > most straightforward solution is to upgrade kfree_mult to a long.
> > > Since this depends on CONFIG_RCU_PERF_TEST
> 
> So the proper fix is Kefeng's patch from April:
> "[PATCH -next] rcuperf: Fix printk format warning"
> https://lore.kernel.org/r/20200417040245.66382-1-wangkefeng.wang@huawei.com

Apologies for not having followed up on this one.

I applied this commit and sent the pull request, CCing you.

							Thanx, Paul

> ":"--
> > Makes sense, and I have queued the patch below, which I am assuming
> > that you want in the upcoming merge window.  If you don't tell me
> > otherwise, I will send you an urgent pull request later today.
> > Or, if you just put it directly into -tip yourself:
> >
> > Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
> >
> > Either way, please let me know.
> >
> > > BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> > > to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> > > mistakenly believe that it's somehow related to perf, while it isn't. =B-)
> >
> > Fair enough, especially given that perf was there first and is also way
> > more heavily used.  ;-)
> >
> > But I am guessing that this one is OK for the v5.9 merge window.
> > Either way, I will update as you say.
> >
> >                                                         Thanx, Paul
> >
> > ------------------------------------------------------------------------
> >
> > commit 2fbc7d67a2ed108e3ac63296670fecb3a42fddd0
> > Author: Ingo Molnar <mingo@kernel.org>
> > Date:   Tue May 26 12:10:01 2020 -0700
> >
> >     rcuperf: Fix kfree_mult to match printk() format
> >
> >     This commit changes the type of kfree_mult from int to long in order
> >     to match the printk() format on 32-bit systems.
> >
> >     Reported-by: kbuild test robot <lkp@intel.com>
> >     Signed-off-by: Ingo Molnar <mingo@kernel.org>
> >     Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
> >
> > diff --git a/kernel/rcu/rcuperf.c b/kernel/rcu/rcuperf.c
> > index d906ca9..fb3a1f0 100644
> > --- a/kernel/rcu/rcuperf.c
> > +++ b/kernel/rcu/rcuperf.c
> > @@ -93,7 +93,7 @@ torture_param(bool, shutdown, RCUPERF_SHUTDOWN,
> >  torture_param(int, verbose, 1, "Enable verbose debugging printk()s");
> >  torture_param(int, writer_holdoff, 0, "Holdoff (us) between GPs, zero to disable");
> >  torture_param(int, kfree_rcu_test, 0, "Do we run a kfree_rcu() perf test?");
> > -torture_param(int, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
> > +torture_param(long, kfree_mult, 1, "Multiple of kfree_obj size to allocate.");
> >
> >  static char *perf_type = "rcu";
> >  module_param(perf_type, charp, 0444);
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> -- 
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
> 
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Paul E. McKenney]

On Tue, May 26, 2020 at 09:14:13PM -0400, Joel Fernandes wrote:
> On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> [...]
> > ./include/linux/kern_levels.h:5:18: warning: format ‘%lu’ expects argument
> > of type ‘long unsigned int’, but argument 2 has type ‘unsigned int’
> > [-Wformat=] 5 | #define KERN_SOH "\001"  /* ASCII Start Of Header */ |
> > ^~~~~~
> > ./include/linux/kern_levels.h:9:20: note: in expansion of macro ‘KERN_SOH’
> >     9 | #define KERN_ALERT KERN_SOH "1" /* action must be taken immediately */
> >       |                    ^~~~~~~~
> > ./include/linux/printk.h:295:9: note: in expansion of macro ‘KERN_ALERT’
> >   295 |  printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
> >       |         ^~~~~~~~~~
> > kernel/rcu/rcuperf.c:726:2: note: in expansion of macro ‘pr_alert’
> >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> >       |  ^~~~~~~~
> > kernel/rcu/rcuperf.c:726:32: note: format string is defined here
> >   726 |  pr_alert("kfree object size=%lu\n", kfree_mult * sizeof(struct kfree_obj));
> >       |                              ~~^
> >       |                                |
> >       |                                long unsigned int
> >       |                              %u
> > 
> > 
> > The reason for the warning is that both kfree_mult and sizeof() are 
> > 'int' types on 32-bit kernels, while the format string expects a long.
> > 
> > Instead of casting the type to long or tweaking the format string, the 
> > most straightforward solution is to upgrade kfree_mult to a long. 
> > Since this depends on CONFIG_RCU_PERF_TEST
> 
> Thanks for fixing it.
> 
> > BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> > to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> > mistakenly believe that it's somehow related to perf, while it isn't. =B-)
> 
> Would it be better to call it 'RCUPERF_TEST' instead of the
> 'RCU_PERFORMANCE_TEST' you are proposing? I feel the word 'PERFORMANCE' is
> too long.  Also, 'rcuperf test' instead of the 'rcu performance test' you are
> proposing.  I am Ok with doing it however you and Paul want it though, let me
> know.

As long as we are bikeshedding the name...  How about refscale.c and
RCU_REF_SCALE_TEST on the one hand and rcuscale.c and RCU_SCALE_TEST on
the other?  That keeps the names reasonably short and does not allude
to perf at all.

> Paul, should I send you a renaming patch for the new performance tests as
> well (which I believe should be in the -dev branch).

I am still modifying refperf/refscale/refwhatever, so I will update
that one.

						Thanx, Paul

Re: [PATCH] rcu/performance: Fix kfree_perf_init() build warning on 32-bit kernels

[Paul E. McKenney]

On Wed, Jun 03, 2020 at 11:11:09AM -0700, Paul E. McKenney wrote:
> On Tue, May 26, 2020 at 09:14:13PM -0400, Joel Fernandes wrote:
> > On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:

[ . . . ]

> > > BTW., could we please also rename this code from 'PERF_TEST'/'perf test'
> > > to 'PERFORMANCE_TEST'/'performance test'? At first glance I always
> > > mistakenly believe that it's somehow related to perf, while it isn't. =B-)
> > 
> > Would it be better to call it 'RCUPERF_TEST' instead of the
> > 'RCU_PERFORMANCE_TEST' you are proposing? I feel the word 'PERFORMANCE' is
> > too long.  Also, 'rcuperf test' instead of the 'rcu performance test' you are
> > proposing.  I am Ok with doing it however you and Paul want it though, let me
> > know.
> 
> As long as we are bikeshedding the name...  How about refscale.c and
> RCU_REF_SCALE_TEST on the one hand and rcuscale.c and RCU_SCALE_TEST on
> the other?  That keeps the names reasonably short and does not allude
> to perf at all.

Hearing no objections, I will go with the scale/SCALE names.

						Thanx, Paul