2020-02-09 10:49:12

by Baoquan He

Subject: [PATCH 2/7] mm/sparse.c: Introduce a new function clear_subsection_map()

Wrap the codes clearing subsection map of one memory region in
section_deactivate() into clear_subsection_map().

Signed-off-by: Baoquan He <[email protected]>
---
mm/sparse.c | 44 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 9ad741ccbeb6..696f6b9f706e 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -726,14 +726,25 @@ static void free_map_bootmem(struct page *memmap)
}
#endif /* CONFIG_SPARSEMEM_VMEMMAP */

-static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
- struct vmem_altmap *altmap)
+/**
+ * clear_subsection_map - Clear subsection map of one memory region
+ *
+ * @pfn - start pfn of the memory range
+ * @nr_pages - number of pfns to add in the region
+ *
+ * This is only intended for hotplug, and clear the related subsection
+ * map inside one section.
+ *
+ * Return:
+ * * -EINVAL - Section already deactived.
+ * * 0 - Subsection map is emptied.
+ * * 1 - Subsection map is not empty.
+ */
+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
{
DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
struct mem_section *ms = __pfn_to_section(pfn);
- bool section_is_early = early_section(ms);
- struct page *memmap = NULL;
unsigned long *subsection_map = ms->usage
? &ms->usage->subsection_map[0] : NULL;

@@ -744,8 +755,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
"section already deactivated (%#lx + %ld)\n",
pfn, nr_pages))
- return;
+ return -EINVAL;
+
+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);

+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
+ return 0;
+
+ return 1;
+}
+
+static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
+ struct vmem_altmap *altmap)
+{
+ struct mem_section *ms = __pfn_to_section(pfn);
+ bool section_is_early = early_section(ms);
+ struct page *memmap = NULL;
+ int rc;
+
+
+ rc = clear_subsection_map(pfn, nr_pages);
+ if(IS_ERR_VALUE((unsigned long)rc))
+ return;
/*
* There are 3 cases to handle across two configurations
* (SPARSEMEM_VMEMMAP={y,n}):
@@ -763,8 +794,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
*
* For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
*/
- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) {
+ if (!rc) {
unsigned long section_nr = pfn_to_section_nr(pfn);

/*
--
2.17.2

2020-02-09 23:07:25

by Wei Yang

Subject: Re: [PATCH 2/7] mm/sparse.c: Introduce a new function clear_subsection_map()

On Sun, Feb 09, 2020 at 06:48:21PM +0800, Baoquan He wrote:
>Wrap the codes clearing subsection map of one memory region in
>section_deactivate() into clear_subsection_map().
>

Patch 1 and 2 server the same purpose -- to #ifdef the VMEMMAP.

I suggest to merge these two.

>Signed-off-by: Baoquan He <[email protected]>
>---
> mm/sparse.c | 44 +++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 37 insertions(+), 7 deletions(-)
>
>diff --git a/mm/sparse.c b/mm/sparse.c
>index 9ad741ccbeb6..696f6b9f706e 100644
>--- a/mm/sparse.c
>+++ b/mm/sparse.c
>@@ -726,14 +726,25 @@ static void free_map_bootmem(struct page *memmap)
> }
> #endif /* CONFIG_SPARSEMEM_VMEMMAP */
>
>-static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>- struct vmem_altmap *altmap)
>+/**
>+ * clear_subsection_map - Clear subsection map of one memory region
>+ *
>+ * @pfn - start pfn of the memory range
>+ * @nr_pages - number of pfns to add in the region
>+ *
>+ * This is only intended for hotplug, and clear the related subsection
>+ * map inside one section.
>+ *
>+ * Return:
>+ * * -EINVAL - Section already deactived.
>+ * * 0 - Subsection map is emptied.
>+ * * 1 - Subsection map is not empty.
>+ */
>+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
> {
> DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
> DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
> struct mem_section *ms = __pfn_to_section(pfn);
>- bool section_is_early = early_section(ms);
>- struct page *memmap = NULL;
> unsigned long *subsection_map = ms->usage
> ? &ms->usage->subsection_map[0] : NULL;
>
>@@ -744,8 +755,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
> "section already deactivated (%#lx + %ld)\n",
> pfn, nr_pages))
>- return;
>+ return -EINVAL;
>+
>+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
>
>+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
>+ return 0;
>+
>+ return 1;
>+}
>+
>+static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>+ struct vmem_altmap *altmap)
>+{
>+ struct mem_section *ms = __pfn_to_section(pfn);
>+ bool section_is_early = early_section(ms);
>+ struct page *memmap = NULL;
>+ int rc;
>+
>+
>+ rc = clear_subsection_map(pfn, nr_pages);
>+ if(IS_ERR_VALUE((unsigned long)rc))
>+ return;
> /*
> * There are 3 cases to handle across two configurations
> * (SPARSEMEM_VMEMMAP={y,n}):
>@@ -763,8 +794,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> *
> * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
> */
>- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
>- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) {
>+ if (!rc) {
> unsigned long section_nr = pfn_to_section_nr(pfn);
>
> /*
>--
>2.17.2

--
Wei Yang
Help you, Help me

2020-02-10 03:37:33

by Baoquan He

Subject: Re: [PATCH 2/7] mm/sparse.c: Introduce a new function clear_subsection_map()

On 02/10/20 at 07:07am, Wei Yang wrote:
> On Sun, Feb 09, 2020 at 06:48:21PM +0800, Baoquan He wrote:
> >Wrap the codes clearing subsection map of one memory region in
> >section_deactivate() into clear_subsection_map().
> >
>
> Patch 1 and 2 server the same purpose -- to #ifdef the VMEMMAP.

Hmm, I didn't say patch 1 and 2 are preparation works because they had
better be done even if we don't take off subsection map from
SPARSEMEM|!VMEMMAP case. Wrapping the subsection map filling and clearing
codes into separate new functions, can make section_activate() and
section_deactivate() much clearer on code logic.

If you don't mind, I will keep them for now, and see what other people
will say.

Thanks
Baoquan

>
> >---
> > mm/sparse.c | 44 +++++++++++++++++++++++++++++++++++++-------
> > 1 file changed, 37 insertions(+), 7 deletions(-)
> >
> >diff --git a/mm/sparse.c b/mm/sparse.c
> >index 9ad741ccbeb6..696f6b9f706e 100644
> >--- a/mm/sparse.c
> >+++ b/mm/sparse.c
> >@@ -726,14 +726,25 @@ static void free_map_bootmem(struct page *memmap)
> > }
> > #endif /* CONFIG_SPARSEMEM_VMEMMAP */
> >
> >-static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> >- struct vmem_altmap *altmap)
> >+/**
> >+ * clear_subsection_map - Clear subsection map of one memory region
> >+ *
> >+ * @pfn - start pfn of the memory range
> >+ * @nr_pages - number of pfns to add in the region
> >+ *
> >+ * This is only intended for hotplug, and clear the related subsection
> >+ * map inside one section.
> >+ *
> >+ * Return:
> >+ * * -EINVAL - Section already deactived.
> >+ * * 0 - Subsection map is emptied.
> >+ * * 1 - Subsection map is not empty.
> >+ */
> >+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
> > {
> > DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
> > DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
> > struct mem_section *ms = __pfn_to_section(pfn);
> >- bool section_is_early = early_section(ms);
> >- struct page *memmap = NULL;
> > unsigned long *subsection_map = ms->usage
> > ? &ms->usage->subsection_map[0] : NULL;
> >
> >@@ -744,8 +755,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> > if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
> > "section already deactivated (%#lx + %ld)\n",
> > pfn, nr_pages))
> >- return;
> >+ return -EINVAL;
> >+
> >+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
> >
> >+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
> >+ return 0;
> >+
> >+ return 1;
> >+}
> >+
> >+static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> >+ struct vmem_altmap *altmap)
> >+{
> >+ struct mem_section *ms = __pfn_to_section(pfn);
> >+ bool section_is_early = early_section(ms);
> >+ struct page *memmap = NULL;
> >+ int rc;
> >+
> >+
> >+ rc = clear_subsection_map(pfn, nr_pages);
> >+ if(IS_ERR_VALUE((unsigned long)rc))
> >+ return;
> > /*
> > * There are 3 cases to handle across two configurations
> > * (SPARSEMEM_VMEMMAP={y,n}):
> >@@ -763,8 +794,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
> > *
> > * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
> > */
> >- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
> >- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) {
> >+ if (!rc) {
> > unsigned long section_nr = pfn_to_section_nr(pfn);
> >
> > /*
> >--
> >2.17.2
>
> --
> Wei Yang
> Help you, Help me
>

2020-02-10 06:03:31

by Wei Yang

Subject: Re: [PATCH 2/7] mm/sparse.c: Introduce a new function clear_subsection_map()

On Mon, Feb 10, 2020 at 11:36:27AM +0800, Baoquan He wrote:
>On 02/10/20 at 07:07am, Wei Yang wrote:
>> On Sun, Feb 09, 2020 at 06:48:21PM +0800, Baoquan He wrote:
>> >Wrap the codes clearing subsection map of one memory region in
>> >section_deactivate() into clear_subsection_map().
>> >
>>
>> Patch 1 and 2 server the same purpose -- to #ifdef the VMEMMAP.
>
>Hmm, I didn't say patch 1 and 2 are preparation works because they had
>better be done even if we don't take off subsection map from
>SPARSEMEM|!VMEMMAP case. Wrapping the subsection map filling and clearing
>codes into separate new functions, can make section_activate() and
>section_deactivate() much clearer on code logic.
>
>If you don't mind, I will keep them for now, and see what other people
>will say.

No objection.

>
>Thanks
>Baoquan
>
>>
>> >---
>> > mm/sparse.c | 44 +++++++++++++++++++++++++++++++++++++-------
>> > 1 file changed, 37 insertions(+), 7 deletions(-)
>> >
>> >diff --git a/mm/sparse.c b/mm/sparse.c
>> >index 9ad741ccbeb6..696f6b9f706e 100644
>> >--- a/mm/sparse.c
>> >+++ b/mm/sparse.c
>> >@@ -726,14 +726,25 @@ static void free_map_bootmem(struct page *memmap)
>> > }
>> > #endif /* CONFIG_SPARSEMEM_VMEMMAP */
>> >
>> >-static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>> >- struct vmem_altmap *altmap)
>> >+/**
>> >+ * clear_subsection_map - Clear subsection map of one memory region
>> >+ *
>> >+ * @pfn - start pfn of the memory range
>> >+ * @nr_pages - number of pfns to add in the region
>> >+ *
>> >+ * This is only intended for hotplug, and clear the related subsection
>> >+ * map inside one section.
>> >+ *
>> >+ * Return:
>> >+ * * -EINVAL - Section already deactived.
>> >+ * * 0 - Subsection map is emptied.
>> >+ * * 1 - Subsection map is not empty.
>> >+ */
>> >+static int clear_subsection_map(unsigned long pfn, unsigned long nr_pages)
>> > {
>> > DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 };
>> > DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 };
>> > struct mem_section *ms = __pfn_to_section(pfn);
>> >- bool section_is_early = early_section(ms);
>> >- struct page *memmap = NULL;
>> > unsigned long *subsection_map = ms->usage
>> > ? &ms->usage->subsection_map[0] : NULL;
>> >
>> >@@ -744,8 +755,28 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>> > if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION),
>> > "section already deactivated (%#lx + %ld)\n",
>> > pfn, nr_pages))
>> >- return;
>> >+ return -EINVAL;
>> >+
>> >+ bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
>> >
>> >+ if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION))
>> >+ return 0;
>> >+
>> >+ return 1;
>> >+}
>> >+
>> >+static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>> >+ struct vmem_altmap *altmap)
>> >+{
>> >+ struct mem_section *ms = __pfn_to_section(pfn);
>> >+ bool section_is_early = early_section(ms);
>> >+ struct page *memmap = NULL;
>> >+ int rc;
>> >+
>> >+
>> >+ rc = clear_subsection_map(pfn, nr_pages);
>> >+ if(IS_ERR_VALUE((unsigned long)rc))
>> >+ return;
>> > /*
>> > * There are 3 cases to handle across two configurations
>> > * (SPARSEMEM_VMEMMAP={y,n}):
>> >@@ -763,8 +794,7 @@ static void section_deactivate(unsigned long pfn, unsigned long nr_pages,
>> > *
>> > * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified
>> > */
>> >- bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION);
>> >- if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) {
>> >+ if (!rc) {
>> > unsigned long section_nr = pfn_to_section_nr(pfn);
>> >
>> > /*
>> >--
>> >2.17.2
>>
>> --
>> Wei Yang
>> Help you, Help me
>>

--
Wei Yang
Help you, Help me