Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Tue, 17 May 2016, Michal Hocko wrote:
> On Mon 16-05-16 15:36:56, Andrew Morton wrote:
> > On Mon, 16 May 2016 16:23:33 +0200 Michal Hocko wrote:
> >
> > > Andrew, I think that the following is more straightforward fix and
> > > should be folded in to the patch which has introduced vmstat_refresh.
> > > ---
> > > >From b8dd18fb7df040e1bfe61aadde1d903589de15e4 Mon Sep 17 00:00:00 2001
> > > From: Michal Hocko
> > > Date: Mon, 16 May 2016 16:19:53 +0200
> > > Subject: [PATCH] mmotm:
> > > mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
> > >
> > > Arnd has reported:
> > > In randconfig builds with sysfs, procfs and numa all disabled,
> > > but SMP enabled, we now get a link error in the newly introduced
> > > vmstat_refresh function:
> > >
> > > mm/built-in.o: In function `vmstat_refresh':
> > > :(.text+0x15c78): undefined reference to `vmstat_text'
> > >
> > > vmstat_refresh is proc_fs specific so there is no reason to define it
> > > when !CONFIG_PROC_FS.
> >
> > I already had this:
> >
> > From: Christoph Lameter
> > Subject: Do not build vmstat_refresh if there is no procfs support
> >
> > It makes no sense to build functionality into the kernel that
> > cannot be used and causes build issues.
> >
> > Link:
> > http://lkml.kernel.org/r/alpine.deb.2.20.1605111011260.9...@east.gentwo.org
> > Signed-off-by: Christoph Lameter
> > Reported-by: Arnd Bergmann
> > Signed-off-by: Andrew Morton
>
> But this is broken:
> http://lkml.kernel.org/r/20160516073144.ga23...@dhcp22.suse.cz and
> kbuild robot agrees
> http://lkml.kernel.org/r/201605171333.anqjcwpy%fengguang...@intel.com
Sorry for my noise, sorry for my silence, thanks to Arnd and everyone
for chipping in. But now I try it, I find that even Michal's is not
quite right: if you build without CONFIG_PROC_FS, then it gives you
mm/vmstat.c:1381:13: warning: `refresh_vm_stats' defined but not used
[-Wunused-function]
(well, that was on a tree with different line numbering).
So here's my attempt...
Signed-off-by: Hugh Dickins
---
Fix to merge into mm-proc-sys-vm-stat_refresh-to-force-vmstat-update.patch
mm/vmstat.c |2 ++
1 file changed, 2 insertions(+)
--- 4.6-rc7-mm1/mm/vmstat.c 2016-05-14 08:29:10.609386264 -0700
+++ linux/mm/vmstat.c 2016-05-17 17:43:02.861862648 -0700
@@ -1365,6 +1365,7 @@ static struct workqueue_struct *vmstat_w
static DEFINE_PER_CPU(struct delayed_work, vmstat_work);
int sysctl_stat_interval __read_mostly = HZ;
+#ifdef CONFIG_PROC_FS
static void refresh_vm_stats(struct work_struct *work)
{
refresh_cpu_vm_stats(true);
@@ -1422,6 +1423,7 @@ int vmstat_refresh(struct ctl_table *tab
*lenp = 0;
return 0;
}
+#endif /* CONFIG_PROC_FS */
static void vmstat_update(struct work_struct *w)
{
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Mon 16-05-16 15:36:56, Andrew Morton wrote:
> On Mon, 16 May 2016 16:23:33 +0200 Michal Hocko wrote:
>
> > Andrew, I think that the following is more straightforward fix and
> > should be folded in to the patch which has introduced vmstat_refresh.
> > ---
> > >From b8dd18fb7df040e1bfe61aadde1d903589de15e4 Mon Sep 17 00:00:00 2001
> > From: Michal Hocko
> > Date: Mon, 16 May 2016 16:19:53 +0200
> > Subject: [PATCH] mmotm:
> > mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
> >
> > Arnd has reported:
> > In randconfig builds with sysfs, procfs and numa all disabled,
> > but SMP enabled, we now get a link error in the newly introduced
> > vmstat_refresh function:
> >
> > mm/built-in.o: In function `vmstat_refresh':
> > :(.text+0x15c78): undefined reference to `vmstat_text'
> >
> > vmstat_refresh is proc_fs specific so there is no reason to define it
> > when !CONFIG_PROC_FS.
>
> I already had this:
>
> From: Christoph Lameter
> Subject: Do not build vmstat_refresh if there is no procfs support
>
> It makes no sense to build functionality into the kernel that
> cannot be used and causes build issues.
>
> Link:
> http://lkml.kernel.org/r/alpine.deb.2.20.1605111011260.9...@east.gentwo.org
> Signed-off-by: Christoph Lameter
> Reported-by: Arnd Bergmann
> Signed-off-by: Andrew Morton
But this is broken:
http://lkml.kernel.org/r/20160516073144.ga23...@dhcp22.suse.cz and
kbuild robot agrees
http://lkml.kernel.org/r/201605171333.anqjcwpy%fengguang...@intel.com
> ---
>
> mm/vmstat.c |4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff -puN mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
> mm/vmstat.c
> --- a/mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
> +++ a/mm/vmstat.c
> @@ -1371,7 +1371,6 @@ static const struct file_operations proc
> .llseek = seq_lseek,
> .release= seq_release,
> };
> -#endif /* CONFIG_PROC_FS */
>
> #ifdef CONFIG_SMP
> static struct workqueue_struct *vmstat_wq;
> @@ -1436,7 +1435,10 @@ int vmstat_refresh(struct ctl_table *tab
> *lenp = 0;
> return 0;
> }
> +#endif /* CONFIG_SMP */
> +#endif /* CONFIG_PROC_FS */
>
> +#ifdef CONFIG_SMP
> static void vmstat_update(struct work_struct *w)
> {
> if (refresh_cpu_vm_stats(true)) {
> _
--
Michal Hocko
SUSE Labs
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Mon, 16 May 2016 16:23:33 +0200 Michal Hocko wrote:
> Andrew, I think that the following is more straightforward fix and
> should be folded in to the patch which has introduced vmstat_refresh.
> ---
> >From b8dd18fb7df040e1bfe61aadde1d903589de15e4 Mon Sep 17 00:00:00 2001
> From: Michal Hocko
> Date: Mon, 16 May 2016 16:19:53 +0200
> Subject: [PATCH] mmotm: mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
>
> Arnd has reported:
> In randconfig builds with sysfs, procfs and numa all disabled,
> but SMP enabled, we now get a link error in the newly introduced
> vmstat_refresh function:
>
> mm/built-in.o: In function `vmstat_refresh':
> :(.text+0x15c78): undefined reference to `vmstat_text'
>
> vmstat_refresh is proc_fs specific so there is no reason to define it
> when !CONFIG_PROC_FS.
I already had this:
From: Christoph Lameter
Subject: Do not build vmstat_refresh if there is no procfs support
It makes no sense to build functionality into the kernel that
cannot be used and causes build issues.
Link:
http://lkml.kernel.org/r/alpine.deb.2.20.1605111011260.9...@east.gentwo.org
Signed-off-by: Christoph Lameter
Reported-by: Arnd Bergmann
Signed-off-by: Andrew Morton
---
mm/vmstat.c |4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
mm/vmstat.c
--- a/mm/vmstat.c~mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
+++ a/mm/vmstat.c
@@ -1371,7 +1371,6 @@ static const struct file_operations proc
.llseek = seq_lseek,
.release= seq_release,
};
-#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SMP
static struct workqueue_struct *vmstat_wq;
@@ -1436,7 +1435,10 @@ int vmstat_refresh(struct ctl_table *tab
*lenp = 0;
return 0;
}
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_PROC_FS */
+#ifdef CONFIG_SMP
static void vmstat_update(struct work_struct *w)
{
if (refresh_cpu_vm_stats(true)) {
_
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
Andrew, I think that the following is more straightforward fix and
should be folded in to the patch which has introduced vmstat_refresh.
---
>From b8dd18fb7df040e1bfe61aadde1d903589de15e4 Mon Sep 17 00:00:00 2001
From: Michal Hocko
Date: Mon, 16 May 2016 16:19:53 +0200
Subject: [PATCH] mmotm: mm-proc-sys-vm-stat_refresh-to-force-vmstat-update-fix
Arnd has reported:
In randconfig builds with sysfs, procfs and numa all disabled,
but SMP enabled, we now get a link error in the newly introduced
vmstat_refresh function:
mm/built-in.o: In function `vmstat_refresh':
:(.text+0x15c78): undefined reference to `vmstat_text'
vmstat_refresh is proc_fs specific so there is no reason to define it
when !CONFIG_PROC_FS.
Reported-by: Arnd Bergmann
Acked-by: Christoph Lameter
Signed-off-by: Michal Hocko
---
mm/vmstat.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 57a24e919907..c759b526287b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1370,6 +1370,7 @@ static void refresh_vm_stats(struct work_struct *work)
refresh_cpu_vm_stats(true);
}
+#ifdef CONFIG_PROC_FS
int vmstat_refresh(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -1422,6 +1423,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
*lenp = 0;
return 0;
}
+#endif
static void vmstat_update(struct work_struct *w)
{
--
2.8.1
--
Michal Hocko
SUSE Labs
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Mon, 16 May 2016, Michal Hocko wrote:
> I agree with Christoph that vmstat_refresh is PROC_FS only so we should
> fix it there. It is not like this would be generally reusable helper...
> Why don't we just do:
Looks good.
Acked-by: Christoph Lameter
> ---
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index 57a24e919907..c759b526287b 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1370,6 +1370,7 @@ static void refresh_vm_stats(struct work_struct *work)
> refresh_cpu_vm_stats(true);
> }
>
> +#ifdef CONFIG_PROC_FS
> int vmstat_refresh(struct ctl_table *table, int write,
> void __user *buffer, size_t *lenp, loff_t *ppos)
> {
> @@ -1422,6 +1423,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
> *lenp = 0;
> return 0;
> }
> +#endif
>
> static void vmstat_update(struct work_struct *w)
> {
>
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Wed 11-05-16 16:54:55, Arnd Bergmann wrote:
> In randconfig builds with sysfs, procfs and numa all disabled,
> but SMP enabled, we now get a link error in the newly introduced
> vmstat_refresh function:
>
> mm/built-in.o: In function `vmstat_refresh':
> :(.text+0x15c78): undefined reference to `vmstat_text'
>
> This modifes the already elaborate #ifdef to also cover that
> configuration.
>
> Signed-off-by: Arnd Bergmann
> Fixes: mmotm ("mm: /proc/sys/vm/stat_refresh to force vmstat update")
I agree with Christoph that vmstat_refresh is PROC_FS only so we should
fix it there. It is not like this would be generally reusable helper...
Why don't we just do:
---
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 57a24e919907..c759b526287b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1370,6 +1370,7 @@ static void refresh_vm_stats(struct work_struct *work)
refresh_cpu_vm_stats(true);
}
+#ifdef CONFIG_PROC_FS
int vmstat_refresh(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
@@ -1422,6 +1423,7 @@ int vmstat_refresh(struct ctl_table *table, int write,
*lenp = 0;
return 0;
}
+#endif
static void vmstat_update(struct work_struct *w)
{
--
Michal Hocko
SUSE Labs
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Wed 11-05-16 10:32:11, Christoph Lameter wrote: > Subject: Do not build vmstat_refresh if there is no procfs support > > It makes no sense to build functionality into the kernel that > cannot be used and causes build issues. > > Signed-off-by: Christoph Lameter > > Index: linux/mm/vmstat.c > === > --- linux.orig/mm/vmstat.c > +++ linux/mm/vmstat.c > @@ -1358,7 +1358,6 @@ static const struct file_operations proc > .llseek = seq_lseek, > .release= seq_release, > }; > -#endif /* CONFIG_PROC_FS */ > > #ifdef CONFIG_SMP > static struct workqueue_struct *vmstat_wq; This doesn't work because it makes the whole vmstat_wq depend on CONFIG_PROC_FS. Which is obviously bad because we both rely on doing the periodic sync even when counters are not exported to the userspace and it wound't compile anyway... -- Michal Hocko SUSE Labs
Re: [PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
On Wed, 11 May 2016, Arnd Bergmann wrote:
> In randconfig builds with sysfs, procfs and numa all disabled,
> but SMP enabled, we now get a link error in the newly introduced
> vmstat_refresh function:
>
> mm/built-in.o: In function `vmstat_refresh':
Hmmm... vmstat_refresh should not be build if CONFIG_PROC_FS is not set
since there will be no way to trigger it. Lets not complicate this
further.
Subject: Do not build vmstat_refresh if there is no procfs support
It makes no sense to build functionality into the kernel that
cannot be used and causes build issues.
Signed-off-by: Christoph Lameter
Index: linux/mm/vmstat.c
===
--- linux.orig/mm/vmstat.c
+++ linux/mm/vmstat.c
@@ -1358,7 +1358,6 @@ static const struct file_operations proc
.llseek = seq_lseek,
.release= seq_release,
};
-#endif /* CONFIG_PROC_FS */
#ifdef CONFIG_SMP
static struct workqueue_struct *vmstat_wq;
@@ -1422,7 +1421,10 @@ int vmstat_refresh(struct ctl_table *tab
*lenp = 0;
return 0;
}
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_PROC_FS */
+#ifdef CONFIG_SMP
static void vmstat_update(struct work_struct *w)
{
if (refresh_cpu_vm_stats(true)) {
[PATCH] mm: unhide vmstat_text definition for CONFIG_SMP
In randconfig builds with sysfs, procfs and numa all disabled,
but SMP enabled, we now get a link error in the newly introduced
vmstat_refresh function:
mm/built-in.o: In function `vmstat_refresh':
:(.text+0x15c78): undefined reference to `vmstat_text'
This modifes the already elaborate #ifdef to also cover that
configuration.
Signed-off-by: Arnd Bergmann
Fixes: mmotm ("mm: /proc/sys/vm/stat_refresh to force vmstat update")
---
mm/vmstat.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 57a24e919907..5367eb9b858b 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -678,7 +678,8 @@ int fragmentation_index(struct zone *zone, unsigned int
order)
}
#endif
-#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || defined(CONFIG_NUMA)
+#if defined(CONFIG_PROC_FS) || defined(CONFIG_SYSFS) || \
+defined(CONFIG_NUMA) || defined(CONFIG_SMP)
#ifdef CONFIG_ZONE_DMA
#define TEXT_FOR_DMA(xx) xx "_dma",
#else
@@ -857,7 +858,7 @@ const char * const vmstat_text[] = {
#endif
#endif /* CONFIG_VM_EVENTS_COUNTERS */
};
-#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA */
+#endif /* CONFIG_PROC_FS || CONFIG_SYSFS || CONFIG_NUMA || CONFIG_SMP */
#if (defined(CONFIG_DEBUG_FS) && defined(CONFIG_COMPACTION)) || \
--
2.7.0
