[PATCH v6 0/5] sparse_init rewrite

[PATCH v6 0/5] sparse_init rewrite

[Pavel Tatashin]

Changelog:
v6 - v5
	- Removed one more obsolete function, as Oscar noticed
	- Replaced BUG_ON with WARN_ON, ALIGN with PTR_ALIGN.
	- Added review-by, and test-by.

v5 - v4
	- Fixed the issue that was reported on ppc64 when
	  CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER is removed
	- Consolidated the new buffer allocation between vmemmap
	  and non-vmemmap variants of sparse layout.
	- Removed all review-by comments, because I had to do
	  significant amount of changes compared to previous version
	  and need another round of review.
	- I also would appreciate if those who reported problems with
	  PPC64 could test this change.
v4 - v3
	- Addressed comments from Dave Hansen
v3 - v1
	- Fixed two issues found by Baoquan He
v1 - v2
	- Addressed comments from Oscar Salvador

In sparse_init() we allocate two large buffers to temporary hold usemap and
memmap for the whole machine. However, we can avoid doing that if we
changed sparse_init() to operated on per-node bases instead of doing it on
the whole machine beforehand.

As shown by Baoquan
http://lkml.kernel.org/r/20180628062857.29658-1-bhe@redhat.com

The buffers are large enough to cause machine stop to boot on small memory
systems.

Another benefit of these changes is that they also obsolete
CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER.

Pavel Tatashin (5):
  mm/sparse: abstract sparse buffer allocations
  mm/sparse: use the new sparse buffer functions in non-vmemmap
  mm/sparse: move buffer init/fini to the common place
  mm/sparse: add new sparse_init_nid() and sparse_init()
  mm/sparse: delete old sparse_init and enable new one

 include/linux/mm.h  |   7 +-
 mm/Kconfig          |   4 -
 mm/sparse-vmemmap.c |  59 +--------
 mm/sparse.c         | 314 ++++++++++++++------------------------------
 4 files changed, 102 insertions(+), 282 deletions(-)

-- 
2.18.0

[PATCH v6 1/5] mm/sparse: abstract sparse buffer allocations

[Pavel Tatashin]

When struct pages are allocated for sparse-vmemmap VA layout, we first try
to allocate one large buffer, and than if that fails allocate struct pages
for each section as we go.

The code that allocates buffer is uses global variables and is spread
across several call sites.

Cleanup the code by introducing three functions to handle the global
buffer:

sparse_buffer_init()	initialize the buffer
sparse_buffer_fini()	free the remaining part of the buffer
sparse_buffer_alloc()	alloc from the buffer, and if buffer is empty
return NULL

Define these functions in sparse.c instead of sparse-vmemmap.c because
later we will use them for non-vmemmap sparse allocations as well.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
---
 include/linux/mm.h  |  4 ++++
 mm/sparse-vmemmap.c | 40 ++++++----------------------------------
 mm/sparse.c         | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 3 files changed, 54 insertions(+), 35 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 577e578eb640..a83d3e0e66d4 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2655,6 +2655,10 @@ void sparse_mem_maps_populate_node(struct page **map_map,
 				   unsigned long map_count,
 				   int nodeid);
 
+unsigned long __init section_map_size(void);
+void sparse_buffer_init(unsigned long size, int nid);
+void sparse_buffer_fini(void);
+void *sparse_buffer_alloc(unsigned long size);
 struct page *sparse_mem_map_populate(unsigned long pnum, int nid,
 		struct vmem_altmap *altmap);
 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index 95e2c7638a5c..b05c7663c640 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -43,12 +43,9 @@ static void * __ref __earlyonly_bootmem_alloc(int node,
 				unsigned long goal)
 {
 	return memblock_virt_alloc_try_nid_raw(size, align, goal,
-					    BOOTMEM_ALLOC_ACCESSIBLE, node);
+					       BOOTMEM_ALLOC_ACCESSIBLE, node);
 }
 
-static void *vmemmap_buf;
-static void *vmemmap_buf_end;
-
 void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 {
 	/* If the main allocator is up use that, fallback to bootmem. */
@@ -76,18 +73,10 @@ void * __meminit vmemmap_alloc_block(unsigned long size, int node)
 /* need to make sure size is all the same during early stage */
 void * __meminit vmemmap_alloc_block_buf(unsigned long size, int node)
 {
-	void *ptr;
-
-	if (!vmemmap_buf)
-		return vmemmap_alloc_block(size, node);
-
-	/* take the from buf */
-	ptr = (void *)ALIGN((unsigned long)vmemmap_buf, size);
-	if (ptr + size > vmemmap_buf_end)
-		return vmemmap_alloc_block(size, node);
-
-	vmemmap_buf = ptr + size;
+	void *ptr = sparse_buffer_alloc(size);
 
+	if (!ptr)
+		ptr = vmemmap_alloc_block(size, node);
 	return ptr;
 }
 
@@ -279,19 +268,9 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 					  unsigned long map_count, int nodeid)
 {
 	unsigned long pnum;
-	unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
-	void *vmemmap_buf_start;
 	int nr_consumed_maps = 0;
 
-	size = ALIGN(size, PMD_SIZE);
-	vmemmap_buf_start = __earlyonly_bootmem_alloc(nodeid, size * map_count,
-			 PMD_SIZE, __pa(MAX_DMA_ADDRESS));
-
-	if (vmemmap_buf_start) {
-		vmemmap_buf = vmemmap_buf_start;
-		vmemmap_buf_end = vmemmap_buf_start + size * map_count;
-	}
-
+	sparse_buffer_init(section_map_size() * map_count, nodeid);
 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 		if (!present_section_nr(pnum))
 			continue;
@@ -303,12 +282,5 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 		       __func__);
 	}
-
-	if (vmemmap_buf_start) {
-		/* need to free left buf */
-		memblock_free_early(__pa(vmemmap_buf),
-				    vmemmap_buf_end - vmemmap_buf);
-		vmemmap_buf = NULL;
-		vmemmap_buf_end = NULL;
-	}
+	sparse_buffer_fini();
 }
diff --git a/mm/sparse.c b/mm/sparse.c
index 2ea8b3dbd0df..9a0a5f598469 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -400,7 +400,14 @@ static void __init sparse_early_usemaps_alloc_node(void *data,
 	}
 }
 
-#ifndef CONFIG_SPARSEMEM_VMEMMAP
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+unsigned long __init section_map_size(void)
+
+{
+	return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
+}
+
+#else
 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
 		struct vmem_altmap *altmap)
 {
@@ -457,6 +464,42 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 }
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
+static void *sparsemap_buf __meminitdata;
+static void *sparsemap_buf_end __meminitdata;
+
+void __init sparse_buffer_init(unsigned long size, int nid)
+{
+	WARN_ON(sparsemap_buf);	/* forgot to call sparse_buffer_fini()? */
+	sparsemap_buf =
+		memblock_virt_alloc_try_nid_raw(size, PAGE_SIZE,
+						__pa(MAX_DMA_ADDRESS),
+						BOOTMEM_ALLOC_ACCESSIBLE, nid);
+	sparsemap_buf_end = sparsemap_buf + size;
+}
+
+void __init sparse_buffer_fini(void)
+{
+	unsigned long size = sparsemap_buf_end - sparsemap_buf;
+
+	if (sparsemap_buf && size > 0)
+		memblock_free_early(__pa(sparsemap_buf), size);
+	sparsemap_buf = NULL;
+}
+
+void * __meminit sparse_buffer_alloc(unsigned long size)
+{
+	void *ptr = NULL;
+
+	if (sparsemap_buf) {
+		ptr = PTR_ALIGN(sparsemap_buf, size);
+		if (ptr + size > sparsemap_buf_end)
+			ptr = NULL;
+		else
+			sparsemap_buf = ptr + size;
+	}
+	return ptr;
+}
+
 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 static void __init sparse_early_mem_maps_alloc_node(void *data,
 				 unsigned long pnum_begin,
-- 
2.18.0

Re: [PATCH v6 1/5] mm/sparse: abstract sparse buffer allocations

[Oscar Salvador]

On Mon, Jul 16, 2018 at 01:44:43PM -0400, Pavel Tatashin wrote:
> When struct pages are allocated for sparse-vmemmap VA layout, we first try
> to allocate one large buffer, and than if that fails allocate struct pages
> for each section as we go.
> 
> The code that allocates buffer is uses global variables and is spread
> across several call sites.
> 
> Cleanup the code by introducing three functions to handle the global
> buffer:
> 
> sparse_buffer_init()	initialize the buffer
> sparse_buffer_fini()	free the remaining part of the buffer
> sparse_buffer_alloc()	alloc from the buffer, and if buffer is empty
> return NULL
> 
> Define these functions in sparse.c instead of sparse-vmemmap.c because
> later we will use them for non-vmemmap sparse allocations as well.
> 
> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>

I did not see anything wrong, so:

Reviewed-by: Oscar Salvador <osalvador@suse.de>

Thanks
-- 
Oscar Salvador
SUSE L3

[PATCH v6 2/5] mm/sparse: use the new sparse buffer functions in non-vmemmap

[Pavel Tatashin]

non-vmemmap sparse also allocated large contiguous chunk of memory, and if
fails falls back to smaller allocations.  Use the same functions to
allocate buffer as the vmemmap-sparse

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
---
 mm/sparse.c | 41 ++++++++++++++---------------------------
 1 file changed, 14 insertions(+), 27 deletions(-)

diff --git a/mm/sparse.c b/mm/sparse.c
index 9a0a5f598469..db4867b62fff 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -408,13 +408,20 @@ unsigned long __init section_map_size(void)
 }
 
 #else
+unsigned long __init section_map_size(void)
+{
+	return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
+}
+
 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
 		struct vmem_altmap *altmap)
 {
-	struct page *map;
-	unsigned long size;
+	unsigned long size = section_map_size();
+	struct page *map = sparse_buffer_alloc(size);
+
+	if (map)
+		return map;
 
-	size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 	map = memblock_virt_alloc_try_nid(size,
 					  PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
 					  BOOTMEM_ALLOC_ACCESSIBLE, nid);
@@ -425,42 +432,22 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 					  unsigned long pnum_end,
 					  unsigned long map_count, int nodeid)
 {
-	void *map;
 	unsigned long pnum;
-	unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
-	int nr_consumed_maps;
-
-	size = PAGE_ALIGN(size);
-	map = memblock_virt_alloc_try_nid_raw(size * map_count,
-					      PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
-					      BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
-	if (map) {
-		nr_consumed_maps = 0;
-		for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
-			if (!present_section_nr(pnum))
-				continue;
-			map_map[nr_consumed_maps] = map;
-			map += size;
-			nr_consumed_maps++;
-		}
-		return;
-	}
+	unsigned long size = section_map_size();
+	int nr_consumed_maps = 0;
 
-	/* fallback */
-	nr_consumed_maps = 0;
+	sparse_buffer_init(size * map_count, nodeid);
 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
-		struct mem_section *ms;
-
 		if (!present_section_nr(pnum))
 			continue;
 		map_map[nr_consumed_maps] =
 				sparse_mem_map_populate(pnum, nodeid, NULL);
 		if (map_map[nr_consumed_maps++])
 			continue;
-		ms = __nr_to_section(pnum);
 		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 		       __func__);
 	}
+	sparse_buffer_fini();
 }
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
-- 
2.18.0

Re: [PATCH v6 2/5] mm/sparse: use the new sparse buffer functions in non-vmemmap

[Oscar Salvador]

On Mon, Jul 16, 2018 at 01:44:44PM -0400, Pavel Tatashin wrote:
> non-vmemmap sparse also allocated large contiguous chunk of memory, and if
> fails falls back to smaller allocations.  Use the same functions to
> allocate buffer as the vmemmap-sparse
> 
> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>

Reviewed-by: Oscar Salvador <osalvador@suse.de>

Thanks
-- 
Oscar Salvador
SUSE L3

[PATCH v6 3/5] mm/sparse: move buffer init/fini to the common place

[Pavel Tatashin]

Now, that both variants of sparse memory use the same buffers to populate
memory map, we can move sparse_buffer_init()/sparse_buffer_fini() to the
common place.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
---
 include/linux/mm.h  |  3 ---
 mm/sparse-vmemmap.c |  2 --
 mm/sparse.c         | 14 +++++++-------
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a83d3e0e66d4..99d8c50adef6 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2655,9 +2655,6 @@ void sparse_mem_maps_populate_node(struct page **map_map,
 				   unsigned long map_count,
 				   int nodeid);
 
-unsigned long __init section_map_size(void);
-void sparse_buffer_init(unsigned long size, int nid);
-void sparse_buffer_fini(void);
 void *sparse_buffer_alloc(unsigned long size);
 struct page *sparse_mem_map_populate(unsigned long pnum, int nid,
 		struct vmem_altmap *altmap);
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index b05c7663c640..cd15f3d252c3 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -270,7 +270,6 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 	unsigned long pnum;
 	int nr_consumed_maps = 0;
 
-	sparse_buffer_init(section_map_size() * map_count, nodeid);
 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 		if (!present_section_nr(pnum))
 			continue;
@@ -282,5 +281,4 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 		       __func__);
 	}
-	sparse_buffer_fini();
 }
diff --git a/mm/sparse.c b/mm/sparse.c
index db4867b62fff..20ca292d8f11 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -401,14 +401,14 @@ static void __init sparse_early_usemaps_alloc_node(void *data,
 }
 
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
-unsigned long __init section_map_size(void)
+static unsigned long __init section_map_size(void)
 
 {
 	return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
 }
 
 #else
-unsigned long __init section_map_size(void)
+static unsigned long __init section_map_size(void)
 {
 	return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 }
@@ -433,10 +433,8 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 					  unsigned long map_count, int nodeid)
 {
 	unsigned long pnum;
-	unsigned long size = section_map_size();
 	int nr_consumed_maps = 0;
 
-	sparse_buffer_init(size * map_count, nodeid);
 	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 		if (!present_section_nr(pnum))
 			continue;
@@ -447,14 +445,13 @@ void __init sparse_mem_maps_populate_node(struct page **map_map,
 		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 		       __func__);
 	}
-	sparse_buffer_fini();
 }
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
 static void *sparsemap_buf __meminitdata;
 static void *sparsemap_buf_end __meminitdata;
 
-void __init sparse_buffer_init(unsigned long size, int nid)
+static void __init sparse_buffer_init(unsigned long size, int nid)
 {
 	WARN_ON(sparsemap_buf);	/* forgot to call sparse_buffer_fini()? */
 	sparsemap_buf =
@@ -464,7 +461,7 @@ void __init sparse_buffer_init(unsigned long size, int nid)
 	sparsemap_buf_end = sparsemap_buf + size;
 }
 
-void __init sparse_buffer_fini(void)
+static void __init sparse_buffer_fini(void)
 {
 	unsigned long size = sparsemap_buf_end - sparsemap_buf;
 
@@ -494,8 +491,11 @@ static void __init sparse_early_mem_maps_alloc_node(void *data,
 				 unsigned long map_count, int nodeid)
 {
 	struct page **map_map = (struct page **)data;
+
+	sparse_buffer_init(section_map_size() * map_count, nodeid);
 	sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
 					 map_count, nodeid);
+	sparse_buffer_fini();
 }
 #else
 static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
-- 
2.18.0

[PATCH v6 4/5] mm/sparse: add new sparse_init_nid() and sparse_init()

[Pavel Tatashin]

sparse_init() requires to temporary allocate two large buffers: usemap_map
and map_map.  Baoquan He has identified that these buffers are so large
that Linux is not bootable on small memory machines, such as a kdump boot.
The buffers are especially large when CONFIG_X86_5LEVEL is set, as they
are scaled to the maximum physical memory size.

Baoquan provided a fix, which reduces these sizes of these buffers, but it
is much better to get rid of them entirely.

Add a new way to initialize sparse memory: sparse_init_nid(), which only
operates within one memory node, and thus allocates memory either in large
contiguous block or allocates section by section.  This eliminates the
need for use of temporary buffers.

For simplified bisecting and review temporarly call sparse_init()
new_sparse_init(), the new interface is going to be enabled as well as old
code removed in the next patch.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
 mm/sparse.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)

diff --git a/mm/sparse.c b/mm/sparse.c
index 20ca292d8f11..248d5d7bbf55 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -200,6 +200,11 @@ static inline int next_present_section_nr(int section_nr)
 	      (section_nr <= __highest_present_section_nr));	\
 	     section_nr = next_present_section_nr(section_nr))
 
+static inline unsigned long first_present_section_nr(void)
+{
+	return next_present_section_nr(-1);
+}
+
 /*
  * Record how many memory sections are marked as present
  * during system bootup.
@@ -668,6 +673,86 @@ void __init sparse_init(void)
 	memblock_free_early(__pa(usemap_map), size);
 }
 
+/*
+ * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
+ * And number of present sections in this node is map_count.
+ */
+static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
+				   unsigned long pnum_end,
+				   unsigned long map_count)
+{
+	unsigned long pnum, usemap_longs, *usemap;
+	struct page *map;
+
+	usemap_longs = BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS);
+	usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid),
+							  usemap_size() *
+							  map_count);
+	if (!usemap) {
+		pr_err("%s: node[%d] usemap allocation failed", __func__, nid);
+		goto failed;
+	}
+	sparse_buffer_init(map_count * section_map_size(), nid);
+	for_each_present_section_nr(pnum_begin, pnum) {
+		if (pnum >= pnum_end)
+			break;
+
+		map = sparse_mem_map_populate(pnum, nid, NULL);
+		if (!map) {
+			pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.",
+			       __func__, nid);
+			pnum_begin = pnum;
+			goto failed;
+		}
+		check_usemap_section_nr(nid, usemap);
+		sparse_init_one_section(__nr_to_section(pnum), pnum, map, usemap);
+		usemap += usemap_longs;
+	}
+	sparse_buffer_fini();
+	return;
+failed:
+	/* We failed to allocate, mark all the following pnums as not present */
+	for_each_present_section_nr(pnum_begin, pnum) {
+		struct mem_section *ms;
+
+		if (pnum >= pnum_end)
+			break;
+		ms = __nr_to_section(pnum);
+		ms->section_mem_map = 0;
+	}
+}
+
+/*
+ * Allocate the accumulated non-linear sections, allocate a mem_map
+ * for each and record the physical to section mapping.
+ */
+void __init new_sparse_init(void)
+{
+	unsigned long pnum_begin = first_present_section_nr();
+	int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
+	unsigned long pnum_end, map_count = 1;
+
+	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
+	set_pageblock_order();
+
+	for_each_present_section_nr(pnum_begin + 1, pnum_end) {
+		int nid = sparse_early_nid(__nr_to_section(pnum_end));
+
+		if (nid == nid_begin) {
+			map_count++;
+			continue;
+		}
+		/* Init node with sections in range [pnum_begin, pnum_end) */
+		sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
+		nid_begin = nid;
+		pnum_begin = pnum_end;
+		map_count = 1;
+	}
+	/* cover the last node */
+	sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count);
+	vmemmap_populate_print_last();
+}
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 
 /* Mark all memory sections within the pfn range as online */
-- 
2.18.0

[PATCH v6 5/5] mm/sparse: delete old sparse_init and enable new one

[Pavel Tatashin]

Rename new_sparse_init() to sparse_init() which enables it.  Delete old
sparse_init() and all the code that became obsolete with.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
---
 include/linux/mm.h  |   6 --
 mm/Kconfig          |   4 -
 mm/sparse-vmemmap.c |  21 ----
 mm/sparse.c         | 237 +-------------------------------------------
 4 files changed, 1 insertion(+), 267 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 99d8c50adef6..726e71475144 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2649,12 +2649,6 @@ extern int randomize_va_space;
 const char * arch_vma_name(struct vm_area_struct *vma);
 void print_vma_addr(char *prefix, unsigned long rip);
 
-void sparse_mem_maps_populate_node(struct page **map_map,
-				   unsigned long pnum_begin,
-				   unsigned long pnum_end,
-				   unsigned long map_count,
-				   int nodeid);
-
 void *sparse_buffer_alloc(unsigned long size);
 struct page *sparse_mem_map_populate(unsigned long pnum, int nid,
 		struct vmem_altmap *altmap);
diff --git a/mm/Kconfig b/mm/Kconfig
index 28fcf54946ea..b78e7cd4e9fe 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -115,10 +115,6 @@ config SPARSEMEM_EXTREME
 config SPARSEMEM_VMEMMAP_ENABLE
 	bool
 
-config SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-	def_bool y
-	depends on SPARSEMEM && X86_64
-
 config SPARSEMEM_VMEMMAP
 	bool "Sparse Memory virtual memmap"
 	depends on SPARSEMEM && SPARSEMEM_VMEMMAP_ENABLE
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index cd15f3d252c3..8301293331a2 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -261,24 +261,3 @@ struct page * __meminit sparse_mem_map_populate(unsigned long pnum, int nid,
 
 	return map;
 }
-
-void __init sparse_mem_maps_populate_node(struct page **map_map,
-					  unsigned long pnum_begin,
-					  unsigned long pnum_end,
-					  unsigned long map_count, int nodeid)
-{
-	unsigned long pnum;
-	int nr_consumed_maps = 0;
-
-	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
-		if (!present_section_nr(pnum))
-			continue;
-
-		map_map[nr_consumed_maps] =
-				sparse_mem_map_populate(pnum, nodeid, NULL);
-		if (map_map[nr_consumed_maps++])
-			continue;
-		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
-		       __func__);
-	}
-}
diff --git a/mm/sparse.c b/mm/sparse.c
index 248d5d7bbf55..10b07eea9a6e 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -205,12 +205,6 @@ static inline unsigned long first_present_section_nr(void)
 	return next_present_section_nr(-1);
 }
 
-/*
- * Record how many memory sections are marked as present
- * during system bootup.
- */
-static int __initdata nr_present_sections;
-
 /* Record a memory area against a node. */
 void __init memory_present(int nid, unsigned long start, unsigned long end)
 {
@@ -240,7 +234,6 @@ void __init memory_present(int nid, unsigned long start, unsigned long end)
 			ms->section_mem_map = sparse_encode_early_nid(nid) |
 							SECTION_IS_ONLINE;
 			section_mark_present(ms);
-			nr_present_sections++;
 		}
 	}
 }
@@ -377,37 +370,8 @@ static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
-static void __init sparse_early_usemaps_alloc_node(void *data,
-				 unsigned long pnum_begin,
-				 unsigned long pnum_end,
-				 unsigned long usemap_count, int nodeid)
-{
-	void *usemap;
-	unsigned long pnum;
-	unsigned long **usemap_map = (unsigned long **)data;
-	int size = usemap_size();
-	int nr_consumed_maps = 0;
-
-	usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
-							  size * usemap_count);
-	if (!usemap) {
-		pr_warn("%s: allocation failed\n", __func__);
-		return;
-	}
-
-	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
-		if (!present_section_nr(pnum))
-			continue;
-		usemap_map[nr_consumed_maps] = usemap;
-		usemap += size;
-		check_usemap_section_nr(nodeid, usemap_map[nr_consumed_maps]);
-		nr_consumed_maps++;
-	}
-}
-
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 static unsigned long __init section_map_size(void)
-
 {
 	return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE);
 }
@@ -432,25 +396,6 @@ struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
 					  BOOTMEM_ALLOC_ACCESSIBLE, nid);
 	return map;
 }
-void __init sparse_mem_maps_populate_node(struct page **map_map,
-					  unsigned long pnum_begin,
-					  unsigned long pnum_end,
-					  unsigned long map_count, int nodeid)
-{
-	unsigned long pnum;
-	int nr_consumed_maps = 0;
-
-	for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
-		if (!present_section_nr(pnum))
-			continue;
-		map_map[nr_consumed_maps] =
-				sparse_mem_map_populate(pnum, nodeid, NULL);
-		if (map_map[nr_consumed_maps++])
-			continue;
-		pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
-		       __func__);
-	}
-}
 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 
 static void *sparsemap_buf __meminitdata;
@@ -489,190 +434,10 @@ void * __meminit sparse_buffer_alloc(unsigned long size)
 	return ptr;
 }
 
-#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-static void __init sparse_early_mem_maps_alloc_node(void *data,
-				 unsigned long pnum_begin,
-				 unsigned long pnum_end,
-				 unsigned long map_count, int nodeid)
-{
-	struct page **map_map = (struct page **)data;
-
-	sparse_buffer_init(section_map_size() * map_count, nodeid);
-	sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
-					 map_count, nodeid);
-	sparse_buffer_fini();
-}
-#else
-static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
-{
-	struct page *map;
-	struct mem_section *ms = __nr_to_section(pnum);
-	int nid = sparse_early_nid(ms);
-
-	map = sparse_mem_map_populate(pnum, nid, NULL);
-	if (map)
-		return map;
-
-	pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
-	       __func__);
-	return NULL;
-}
-#endif
-
 void __weak __meminit vmemmap_populate_print_last(void)
 {
 }
 
-/**
- *  alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
- *  @map: usemap_map for pageblock flags or mmap_map for vmemmap
- *  @unit_size: size of map unit
- */
-static void __init alloc_usemap_and_memmap(void (*alloc_func)
-					(void *, unsigned long, unsigned long,
-					unsigned long, int), void *data,
-					int data_unit_size)
-{
-	unsigned long pnum;
-	unsigned long map_count;
-	int nodeid_begin = 0;
-	unsigned long pnum_begin = 0;
-
-	for_each_present_section_nr(0, pnum) {
-		struct mem_section *ms;
-
-		ms = __nr_to_section(pnum);
-		nodeid_begin = sparse_early_nid(ms);
-		pnum_begin = pnum;
-		break;
-	}
-	map_count = 1;
-	for_each_present_section_nr(pnum_begin + 1, pnum) {
-		struct mem_section *ms;
-		int nodeid;
-
-		ms = __nr_to_section(pnum);
-		nodeid = sparse_early_nid(ms);
-		if (nodeid == nodeid_begin) {
-			map_count++;
-			continue;
-		}
-		/* ok, we need to take cake of from pnum_begin to pnum - 1*/
-		alloc_func(data, pnum_begin, pnum,
-						map_count, nodeid_begin);
-		/* new start, update count etc*/
-		nodeid_begin = nodeid;
-		pnum_begin = pnum;
-		data += map_count * data_unit_size;
-		map_count = 1;
-	}
-	/* ok, last chunk */
-	alloc_func(data, pnum_begin, __highest_present_section_nr+1,
-						map_count, nodeid_begin);
-}
-
-/*
- * Allocate the accumulated non-linear sections, allocate a mem_map
- * for each and record the physical to section mapping.
- */
-void __init sparse_init(void)
-{
-	unsigned long pnum;
-	struct page *map;
-	unsigned long *usemap;
-	unsigned long **usemap_map;
-	int size;
-	int nr_consumed_maps = 0;
-#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-	int size2;
-	struct page **map_map;
-#endif
-
-	/* see include/linux/mmzone.h 'struct mem_section' definition */
-	BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
-
-	/* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
-	set_pageblock_order();
-
-	/*
-	 * map is using big page (aka 2M in x86 64 bit)
-	 * usemap is less one page (aka 24 bytes)
-	 * so alloc 2M (with 2M align) and 24 bytes in turn will
-	 * make next 2M slip to one more 2M later.
-	 * then in big system, the memory will have a lot of holes...
-	 * here try to allocate 2M pages continuously.
-	 *
-	 * powerpc need to call sparse_init_one_section right after each
-	 * sparse_early_mem_map_alloc, so allocate usemap_map at first.
-	 */
-	size = sizeof(unsigned long *) * nr_present_sections;
-	usemap_map = memblock_virt_alloc(size, 0);
-	if (!usemap_map)
-		panic("can not allocate usemap_map\n");
-	alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
-				(void *)usemap_map,
-				sizeof(usemap_map[0]));
-
-#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-	size2 = sizeof(struct page *) * nr_present_sections;
-	map_map = memblock_virt_alloc(size2, 0);
-	if (!map_map)
-		panic("can not allocate map_map\n");
-	alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
-				(void *)map_map,
-				sizeof(map_map[0]));
-#endif
-
-	/*
-	 * The number of present sections stored in nr_present_sections
-	 * are kept the same since mem sections are marked as present in
-	 * memory_present(). In this for loop, we need check which sections
-	 * failed to allocate memmap or usemap, then clear its
-	 * ->section_mem_map accordingly. During this process, we need
-	 * increase 'nr_consumed_maps' whether its allocation of memmap
-	 * or usemap failed or not, so that after we handle the i-th
-	 * memory section, can get memmap and usemap of (i+1)-th section
-	 * correctly.
-	 */
-	for_each_present_section_nr(0, pnum) {
-		struct mem_section *ms;
-
-		if (nr_consumed_maps >= nr_present_sections) {
-			pr_err("nr_consumed_maps goes beyond nr_present_sections\n");
-			break;
-		}
-		ms = __nr_to_section(pnum);
-		usemap = usemap_map[nr_consumed_maps];
-		if (!usemap) {
-			ms->section_mem_map = 0;
-			nr_consumed_maps++;
-			continue;
-		}
-
-#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-		map = map_map[nr_consumed_maps];
-#else
-		map = sparse_early_mem_map_alloc(pnum);
-#endif
-		if (!map) {
-			ms->section_mem_map = 0;
-			nr_consumed_maps++;
-			continue;
-		}
-
-		sparse_init_one_section(__nr_to_section(pnum), pnum, map,
-								usemap);
-		nr_consumed_maps++;
-	}
-
-	vmemmap_populate_print_last();
-
-#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
-	memblock_free_early(__pa(map_map), size2);
-#endif
-	memblock_free_early(__pa(usemap_map), size);
-}
-
 /*
  * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end)
  * And number of present sections in this node is map_count.
@@ -726,7 +491,7 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
  * Allocate the accumulated non-linear sections, allocate a mem_map
  * for each and record the physical to section mapping.
  */
-void __init new_sparse_init(void)
+void __init sparse_init(void)
 {
 	unsigned long pnum_begin = first_present_section_nr();
 	int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin));
-- 
2.18.0

Re: [PATCH v6 5/5] mm/sparse: delete old sparse_init and enable new one

[Oscar Salvador]

On Mon, Jul 16, 2018 at 01:44:47PM -0400, Pavel Tatashin wrote:
> Rename new_sparse_init() to sparse_init() which enables it.  Delete old
> sparse_init() and all the code that became obsolete with.
> 
> Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
> Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

I tested it also with a powerpc vm.
And as I said, the code becomes much more clean now.

Reviewed-by: Oscar Salvador <osalvador@suse.de>

Thanks
-- 
Oscar Salvador
SUSE L3