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) <[email protected]>
AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00
Committer: Paul E. McKenney <[email protected]>
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) <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
---
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) {
* tip-bot2 for Joel Fernandes (Google) <[email protected]> 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) <[email protected]>
> AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00
> Committer: Paul E. McKenney <[email protected]>
> 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) <[email protected]>
> Signed-off-by: Paul E. McKenney <[email protected]>
> ---
> 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 <[email protected]>
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);
On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
>
> * tip-bot2 for Joel Fernandes (Google) <[email protected]> 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) <[email protected]>
> > AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00
> > Committer: Paul E. McKenney <[email protected]>
> > 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) <[email protected]>
> > Signed-off-by: Paul E. McKenney <[email protected]>
> > ---
> > 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 <[email protected]>
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 <[email protected]>
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 <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
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);
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 <[email protected]>
>
> 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);
Hi Paul,
On Tue, May 26, 2020 at 9:17 PM Paul E. McKenney <[email protected]> wrote:
> On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> > * tip-bot2 for Joel Fernandes (Google) <[email protected]> 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) <[email protected]>
> > > AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00
> > > Committer: Paul E. McKenney <[email protected]>
> > > 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) <[email protected]>
> > > Signed-off-by: Paul E. McKenney <[email protected]>
> > > ---
> > > 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/[email protected]
":"--
> 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 <[email protected]>
>
> 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 <[email protected]>
> 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 <[email protected]>
> Signed-off-by: Ingo Molnar <[email protected]>
> Signed-off-by: Paul E. McKenney <[email protected]>
>
> 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 -- [email protected]
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
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 <[email protected]> wrote:
> > On Tue, May 26, 2020 at 08:27:44PM +0200, Ingo Molnar wrote:
> > > * tip-bot2 for Joel Fernandes (Google) <[email protected]> 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) <[email protected]>
> > > > AuthorDate: Mon, 16 Mar 2020 12:32:26 -04:00
> > > > Committer: Paul E. McKenney <[email protected]>
> > > > 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) <[email protected]>
> > > > Signed-off-by: Paul E. McKenney <[email protected]>
> > > > ---
> > > > 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/[email protected]
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 <[email protected]>
> >
> > 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 <[email protected]>
> > 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 <[email protected]>
> > Signed-off-by: Ingo Molnar <[email protected]>
> > Signed-off-by: Paul E. McKenney <[email protected]>
> >
> > 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 -- [email protected]
>
> 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
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
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