This is preparation step to report test failed pfn in new tracepoint
to analyze cma allocation failure problem. There is no functional change
in this patch.
Signed-off-by: Joonsoo Kim <[email protected]>
---
mm/page_isolation.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 4568fd5..6f5ae96 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -212,7 +212,7 @@ int undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
*
* Returns 1 if all pages in the range are isolated.
*/
-static int
+static unsigned long
__test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
bool skip_hwpoisoned_pages)
{
@@ -237,9 +237,8 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn,
else
break;
}
- if (pfn < end_pfn)
- return 0;
- return 1;
+
+ return pfn;
}
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
@@ -248,7 +247,6 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
unsigned long pfn, flags;
struct page *page;
struct zone *zone;
- int ret;
/*
* Note: pageblock_nr_pages != MAX_ORDER. Then, chunks of free pages
@@ -266,10 +264,11 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
/* Check all pages are free or marked as ISOLATED */
zone = page_zone(page);
spin_lock_irqsave(&zone->lock, flags);
- ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
+ pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
skip_hwpoisoned_pages);
spin_unlock_irqrestore(&zone->lock, flags);
- return ret ? 0 : -EBUSY;
+
+ return (pfn < end_pfn) ? -EBUSY : 0;
}
struct page *alloc_migrate_target(struct page *page, unsigned long private,
--
1.9.1
cma allocation should be guranteeded to succeed, but, sometimes,
it could be failed in current implementation. To track down
the problem, we need to know which page is problematic and
this new tracepoint will report it.
Signed-off-by: Joonsoo Kim <[email protected]>
---
include/trace/events/cma.h | 26 ++++++++++++++++++++++++++
mm/page_isolation.c | 5 +++++
2 files changed, 31 insertions(+)
diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
index d7cd961..82281b0 100644
--- a/include/trace/events/cma.h
+++ b/include/trace/events/cma.h
@@ -60,6 +60,32 @@ TRACE_EVENT(cma_release,
__entry->count)
);
+TRACE_EVENT(test_pages_isolated,
+
+ TP_PROTO(
+ unsigned long start_pfn,
+ unsigned long end_pfn,
+ unsigned long fin_pfn),
+
+ TP_ARGS(start_pfn, end_pfn, fin_pfn),
+
+ TP_STRUCT__entry(
+ __field(unsigned long, start_pfn)
+ __field(unsigned long, end_pfn)
+ __field(unsigned long, fin_pfn)
+ ),
+
+ TP_fast_assign(
+ __entry->start_pfn = start_pfn;
+ __entry->end_pfn = end_pfn;
+ __entry->fin_pfn = fin_pfn;
+ ),
+
+ TP_printk("start_pfn=0x%lx end_pfn=0x%lx fin_pfn=0x%lx ret=%s",
+ __entry->start_pfn, __entry->end_pfn, __entry->fin_pfn,
+ __entry->end_pfn == __entry->fin_pfn ? "success" : "fail")
+);
+
#endif /* _TRACE_CMA_H */
/* This part must be outside protection */
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index 6f5ae96..bda0fea 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -7,6 +7,8 @@
#include <linux/pageblock-flags.h>
#include <linux/memory.h>
#include <linux/hugetlb.h>
+#include <trace/events/cma.h>
+
#include "internal.h"
static int set_migratetype_isolate(struct page *page,
@@ -268,6 +270,9 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
skip_hwpoisoned_pages);
spin_unlock_irqrestore(&zone->lock, flags);
+#ifdef CONFIG_CMA
+ trace_test_pages_isolated(start_pfn, end_pfn, pfn);
+#endif
return (pfn < end_pfn) ? -EBUSY : 0;
}
--
1.9.1
Now, we have tracepoint in test_pages_isolated() to notify
pfn which cannot be isolated. But, in alloc_contig_range(),
some error path doesn't call test_pages_isolated() so it's still
hard to know exact pfn that causes allocation failure.
This patch change this situation by calling test_pages_isolated()
in almost error path. In allocation failure case, some overhead
is added by this change, but, allocation failure is really rare
event so it would not matter.
In fatal signal pending case, we don't call test_pages_isolated()
because this failure is intentional one.
Signed-off-by: Joonsoo Kim <[email protected]>
---
mm/page_alloc.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d89960d..e78d78f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6756,8 +6756,12 @@ int alloc_contig_range(unsigned long start, unsigned long end,
if (ret)
return ret;
+ /*
+ * In case of -EBUSY, we'd like to know which page causes problem.
+ * So, just fall through. We will check it in test_pages_isolated().
+ */
ret = __alloc_contig_migrate_range(&cc, start, end);
- if (ret)
+ if (ret && ret != -EBUSY)
goto done;
/*
@@ -6784,8 +6788,8 @@ int alloc_contig_range(unsigned long start, unsigned long end,
outer_start = start;
while (!PageBuddy(pfn_to_page(outer_start))) {
if (++order >= MAX_ORDER) {
- ret = -EBUSY;
- goto done;
+ outer_start = start;
+ break;
}
outer_start &= ~0UL << order;
}
--
1.9.1
On Mon, 9 Nov 2015, Joonsoo Kim wrote:
> This is preparation step to report test failed pfn in new tracepoint
> to analyze cma allocation failure problem. There is no functional change
> in this patch.
>
> Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: David Rientjes <[email protected]>
On Mon, 9 Nov 2015, Joonsoo Kim wrote:
> diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
> index d7cd961..82281b0 100644
> --- a/include/trace/events/cma.h
> +++ b/include/trace/events/cma.h
> @@ -60,6 +60,32 @@ TRACE_EVENT(cma_release,
> __entry->count)
> );
>
> +TRACE_EVENT(test_pages_isolated,
> +
> + TP_PROTO(
> + unsigned long start_pfn,
> + unsigned long end_pfn,
> + unsigned long fin_pfn),
> +
> + TP_ARGS(start_pfn, end_pfn, fin_pfn),
> +
> + TP_STRUCT__entry(
> + __field(unsigned long, start_pfn)
> + __field(unsigned long, end_pfn)
> + __field(unsigned long, fin_pfn)
> + ),
> +
> + TP_fast_assign(
> + __entry->start_pfn = start_pfn;
> + __entry->end_pfn = end_pfn;
> + __entry->fin_pfn = fin_pfn;
> + ),
> +
> + TP_printk("start_pfn=0x%lx end_pfn=0x%lx fin_pfn=0x%lx ret=%s",
> + __entry->start_pfn, __entry->end_pfn, __entry->fin_pfn,
> + __entry->end_pfn == __entry->fin_pfn ? "success" : "fail")
> +);
> +
> #endif /* _TRACE_CMA_H */
>
> /* This part must be outside protection */
> diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> index 6f5ae96..bda0fea 100644
> --- a/mm/page_isolation.c
> +++ b/mm/page_isolation.c
> @@ -7,6 +7,8 @@
> #include <linux/pageblock-flags.h>
> #include <linux/memory.h>
> #include <linux/hugetlb.h>
> +#include <trace/events/cma.h>
> +
> #include "internal.h"
>
> static int set_migratetype_isolate(struct page *page,
> @@ -268,6 +270,9 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
> skip_hwpoisoned_pages);
> spin_unlock_irqrestore(&zone->lock, flags);
>
> +#ifdef CONFIG_CMA
> + trace_test_pages_isolated(start_pfn, end_pfn, pfn);
> +#endif
> return (pfn < end_pfn) ? -EBUSY : 0;
> }
>
This is also used for memory offlining, so could we generalize the
tracepoint to CONFIG_CMA || CONFIG_MEMORY_HOTREMOVE?
On Mon, Nov 09, 2015 at 02:59:39PM -0800, David Rientjes wrote:
> On Mon, 9 Nov 2015, Joonsoo Kim wrote:
>
> > diff --git a/include/trace/events/cma.h b/include/trace/events/cma.h
> > index d7cd961..82281b0 100644
> > --- a/include/trace/events/cma.h
> > +++ b/include/trace/events/cma.h
> > @@ -60,6 +60,32 @@ TRACE_EVENT(cma_release,
> > __entry->count)
> > );
> >
> > +TRACE_EVENT(test_pages_isolated,
> > +
> > + TP_PROTO(
> > + unsigned long start_pfn,
> > + unsigned long end_pfn,
> > + unsigned long fin_pfn),
> > +
> > + TP_ARGS(start_pfn, end_pfn, fin_pfn),
> > +
> > + TP_STRUCT__entry(
> > + __field(unsigned long, start_pfn)
> > + __field(unsigned long, end_pfn)
> > + __field(unsigned long, fin_pfn)
> > + ),
> > +
> > + TP_fast_assign(
> > + __entry->start_pfn = start_pfn;
> > + __entry->end_pfn = end_pfn;
> > + __entry->fin_pfn = fin_pfn;
> > + ),
> > +
> > + TP_printk("start_pfn=0x%lx end_pfn=0x%lx fin_pfn=0x%lx ret=%s",
> > + __entry->start_pfn, __entry->end_pfn, __entry->fin_pfn,
> > + __entry->end_pfn == __entry->fin_pfn ? "success" : "fail")
> > +);
> > +
> > #endif /* _TRACE_CMA_H */
> >
> > /* This part must be outside protection */
> > diff --git a/mm/page_isolation.c b/mm/page_isolation.c
> > index 6f5ae96..bda0fea 100644
> > --- a/mm/page_isolation.c
> > +++ b/mm/page_isolation.c
> > @@ -7,6 +7,8 @@
> > #include <linux/pageblock-flags.h>
> > #include <linux/memory.h>
> > #include <linux/hugetlb.h>
> > +#include <trace/events/cma.h>
> > +
> > #include "internal.h"
> >
> > static int set_migratetype_isolate(struct page *page,
> > @@ -268,6 +270,9 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
> > skip_hwpoisoned_pages);
> > spin_unlock_irqrestore(&zone->lock, flags);
> >
> > +#ifdef CONFIG_CMA
> > + trace_test_pages_isolated(start_pfn, end_pfn, pfn);
> > +#endif
> > return (pfn < end_pfn) ? -EBUSY : 0;
> > }
> >
>
> This is also used for memory offlining, so could we generalize the
> tracepoint to CONFIG_CMA || CONFIG_MEMORY_HOTREMOVE?
Okay. I will make it enabled on CONFIG_MEMORY_ISOLATION so that
CONFIG_CMA || CONFIG_MEMORY_HOTREMOVE || CONFIG_MEMORY_FAILURE can
get benefit from it.
Thanks.
On Mon, Nov 09 2015, Joonsoo Kim wrote:
> This is preparation step to report test failed pfn in new tracepoint
> to analyze cma allocation failure problem. There is no functional change
> in this patch.
>
> Signed-off-by: Joonsoo Kim <[email protected]>
Acked-by: Michal Nazarewicz <[email protected]>
> ---
> mm/page_isolation.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> @@ -266,10 +264,11 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn,
> /* Check all pages are free or marked as ISOLATED */
> zone = page_zone(page);
> spin_lock_irqsave(&zone->lock, flags);
> - ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
> + pfn = __test_page_isolated_in_pageblock(start_pfn, end_pfn,
> skip_hwpoisoned_pages);
> spin_unlock_irqrestore(&zone->lock, flags);
> - return ret ? 0 : -EBUSY;
> +
> + return (pfn < end_pfn) ? -EBUSY : 0;
Parens aren’t necessary. No strong feelings.
> }
>
> struct page *alloc_migrate_target(struct page *page, unsigned long private,
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, ミハウ “mina86” ナザレヴイツ (o o)
ooo +--<[email protected]>--<xmpp:[email protected]>-----ooO--(_)--Ooo--
On Mon, Nov 09 2015, Joonsoo Kim wrote:
> cma allocation should be guranteeded to succeed, but, sometimes,
> it could be failed in current implementation. To track down
> the problem, we need to know which page is problematic and
> this new tracepoint will report it.
>
> Signed-off-by: Joonsoo Kim <[email protected]>
I’m not really familiar with tracing framework but other then that:
Acked-by: Michal Nazarewicz <[email protected]>
> ---
> include/trace/events/cma.h | 26 ++++++++++++++++++++++++++
> mm/page_isolation.c | 5 +++++
> 2 files changed, 31 insertions(+)
--
Best regards, _ _
.o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o
..o | Computer Science, ミハウ “mina86” ナザレヴイツ (o o)
ooo +--<[email protected]>--<xmpp:[email protected]>-----ooO--(_)--Ooo--