Re: linux-next: manual merge of the akpm-current tree with the hmm tree

From: Andrew Morton
Date: Sun Jul 07 2019 - 01:04:31 EST


On Fri, 5 Jul 2019 12:08:15 +0000 Jason Gunthorpe <jgg@xxxxxxxxxxxx> wrote:

> On Thu, Jul 04, 2019 at 04:29:55PM -0700, Dan Williams wrote:
> > Guys, Andrew has kicked the subsection patches out of -mm because of
> > the merge conflicts. Can we hold off on the hmm cleanups for this
> > cycle?
>
> I agree with you we should prioritize your subsection patches over
> CH's cleanup if we cannot have both.
>
> As I said, I'll drop CH's at Andrews request, but I do not want to
> make any changes without being aligned with him.

OK, I had a shot at repairing the damage on top of current linux-next.
The great majority of the issues were in
mm-devm_memremap_pages-enable-sub-section-remap.patch.

Below are the rejects which I saw and below that is my attempt to
resolve it all. Dan, please go through this with a toothcomb. I've
just done an mmotm release with all this in it so please do whatever's
needed to verify that it's all working correctly.


--- kernel/memremap.c~mm-devm_memremap_pages-enable-sub-section-remap
+++ kernel/memremap.c
@@ -58,7 +58,7 @@ static unsigned long pfn_first(struct de
struct vmem_altmap *altmap = &pgmap->altmap;
unsigned long pfn;

- pfn = res->start >> PAGE_SHIFT;
+ pfn = PHYS_PFN(res->start);
if (pgmap->altmap_valid)
pfn += vmem_altmap_offset(altmap);
return pfn;
@@ -95,25 +94,21 @@ static void devm_memremap_pages_release(
pgmap->cleanup(pgmap->ref);

/* pages are dead and unused, undo the arch mapping */
- align_start = res->start & ~(PA_SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), PA_SECTION_SIZE)
- - align_start;
-
- nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
+ nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start)));

mem_hotplug_begin();
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
- pfn = align_start >> PAGE_SHIFT;
+ pfn = PHYS_PFN(res->start);
__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
- align_size >> PAGE_SHIFT, NULL);
+ PHYS_PFN(resource_size(res)), NULL);
} else {
- arch_remove_memory(nid, align_start, align_size,
+ arch_remove_memory(nid, res->start, resource_size(res),
pgmap->altmap_valid ? &pgmap->altmap : NULL);
- kasan_remove_zero_shadow(__va(align_start), align_size);
+ kasan_remove_zero_shadow(__va(res->start), resource_size(res));
}
mem_hotplug_done();

- untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
+ untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
pgmap_array_delete(res);
dev_WARN_ONCE(dev, pgmap->altmap.alloc,
"%s: failed to free all reserved pages\n", __func__);
@@ -140,16 +135,13 @@ static void devm_memremap_pages_release(
*/
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
- resource_size_t align_start, align_size, align_end;
- struct vmem_altmap *altmap = pgmap->altmap_valid ?
- &pgmap->altmap : NULL;
struct resource *res = &pgmap->res;
struct dev_pagemap *conflict_pgmap;
struct mhp_restrictions restrictions = {
/*
* We do not want any optional features only our own memmap
*/
- .altmap = altmap,
+ .altmap = pgmap->altmap_valid ? &pgmap->altmap : NULL,
};
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
@@ -159,12 +151,7 @@ void *devm_memremap_pages(struct device
return ERR_PTR(-EINVAL);
}

- align_start = res->start & ~(PA_SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), PA_SECTION_SIZE)
- - align_start;
- align_end = align_start + align_size - 1;
-
- conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL);
+ conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);
if (conflict_pgmap) {
dev_WARN(dev, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
@@ -220,25 +207,25 @@ void *devm_memremap_pages(struct device
* arch_add_memory().
*/
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
- error = add_pages(nid, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, &restrictions);
+ error = add_pages(nid, PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), &restrictions);
} else {
- error = kasan_add_zero_shadow(__va(align_start), align_size);
+ error = kasan_add_zero_shadow(__va(res->start), resource_size(res));
if (error) {
mem_hotplug_done();
goto err_kasan;
}

- error = arch_add_memory(nid, align_start, align_size,
- &restrictions);
+ error = arch_add_memory(nid, res->start, resource_size(res),
+ &restrictions);
}

if (!error) {
struct zone *zone;

zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
- move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, altmap);
+ move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), restrictions.altmap);
}

mem_hotplug_done();






From: Dan Williams <dan.j.williams@xxxxxxxxx>
Subject: mm/devm_memremap_pages: enable sub-section remap

Teach devm_memremap_pages() about the new sub-section capabilities of
arch_{add,remove}_memory(). Effectively, just replace all usage of
align_start, align_end, and align_size with res->start, res->end, and
resource_size(res). The existing sanity check will still make sure that
the two separate remap attempts do not collide within a sub-section (2MB
on x86).

Link: http://lkml.kernel.org/r/156092355542.979959.10060071713397030576.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> [ppc64]
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Toshi Kani <toshi.kani@xxxxxxx>
Cc: Jérôme Glisse <jglisse@xxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jane Chu <jane.chu@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

kernel/memremap.c | 57 +++++++++++++++++---------------------------
1 file changed, 23 insertions(+), 34 deletions(-)

--- a/kernel/memremap.c~mm-devm_memremap_pages-enable-sub-section-remap
+++ a/kernel/memremap.c
@@ -54,7 +54,7 @@ static void pgmap_array_delete(struct re

static unsigned long pfn_first(struct dev_pagemap *pgmap)
{
- return (pgmap->res.start >> PAGE_SHIFT) +
+ return PHYS_PFN(pgmap->res.start) +
vmem_altmap_offset(pgmap_altmap(pgmap));
}

@@ -98,7 +98,6 @@ static void devm_memremap_pages_release(
struct dev_pagemap *pgmap = data;
struct device *dev = pgmap->dev;
struct resource *res = &pgmap->res;
- resource_size_t align_start, align_size;
unsigned long pfn;
int nid;

@@ -108,25 +107,21 @@ static void devm_memremap_pages_release(
dev_pagemap_cleanup(pgmap);

/* pages are dead and unused, undo the arch mapping */
- align_start = res->start & ~(SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
- - align_start;
-
- nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
+ nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start)));

mem_hotplug_begin();
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
- pfn = align_start >> PAGE_SHIFT;
+ pfn = PHYS_PFN(res->start);
__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
- align_size >> PAGE_SHIFT, NULL);
+ PHYS_PFN(resource_size(res)), NULL);
} else {
- arch_remove_memory(nid, align_start, align_size,
+ arch_remove_memory(nid, res->start, resource_size(res),
pgmap_altmap(pgmap));
- kasan_remove_zero_shadow(__va(align_start), align_size);
+ kasan_remove_zero_shadow(__va(res->start), resource_size(res));
}
mem_hotplug_done();

- untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
+ untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
pgmap_array_delete(res);
dev_WARN_ONCE(dev, pgmap->altmap.alloc,
"%s: failed to free all reserved pages\n", __func__);
@@ -162,13 +157,12 @@ static void dev_pagemap_percpu_release(s
*/
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
- resource_size_t align_start, align_size, align_end;
struct resource *res = &pgmap->res;
struct dev_pagemap *conflict_pgmap;
struct mhp_restrictions restrictions = {
/*
* We do not want any optional features only our own memmap
- */
+ */
.altmap = pgmap_altmap(pgmap),
};
pgprot_t pgprot = PAGE_KERNEL;
@@ -225,12 +219,7 @@ void *devm_memremap_pages(struct device
return ERR_PTR(error);
}

- align_start = res->start & ~(SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
- - align_start;
- align_end = align_start + align_size - 1;
-
- conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL);
+ conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);
if (conflict_pgmap) {
dev_WARN(dev, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
@@ -238,7 +227,7 @@ void *devm_memremap_pages(struct device
goto err_array;
}

- conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL);
+ conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL);
if (conflict_pgmap) {
dev_WARN(dev, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
@@ -246,7 +235,7 @@ void *devm_memremap_pages(struct device
goto err_array;
}

- is_ram = region_intersects(align_start, align_size,
+ is_ram = region_intersects(res->start, resource_size(res),
IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);

if (is_ram != REGION_DISJOINT) {
@@ -267,8 +256,8 @@ void *devm_memremap_pages(struct device
if (nid < 0)
nid = numa_mem_id();

- error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0,
- align_size);
+ error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(res->start), 0,
+ resource_size(res));
if (error)
goto err_pfn_remap;

@@ -286,16 +275,16 @@ void *devm_memremap_pages(struct device
* arch_add_memory().
*/
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
- error = add_pages(nid, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, &restrictions);
+ error = add_pages(nid, PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), &restrictions);
} else {
- error = kasan_add_zero_shadow(__va(align_start), align_size);
+ error = kasan_add_zero_shadow(__va(res->start), resource_size(res));
if (error) {
mem_hotplug_done();
goto err_kasan;
}

- error = arch_add_memory(nid, align_start, align_size,
+ error = arch_add_memory(nid, res->start, resource_size(res),
&restrictions);
}

@@ -303,8 +292,8 @@ void *devm_memremap_pages(struct device
struct zone *zone;

zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
- move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, pgmap_altmap(pgmap));
+ move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), restrictions.altmap);
}

mem_hotplug_done();
@@ -316,8 +305,8 @@ void *devm_memremap_pages(struct device
* to allow us to do the work while not holding the hotplug lock.
*/
memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
- align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, pgmap);
+ PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), pgmap);
percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));

error = devm_add_action_or_reset(dev, devm_memremap_pages_release,
@@ -328,9 +317,9 @@ void *devm_memremap_pages(struct device
return __va(res->start);

err_add_memory:
- kasan_remove_zero_shadow(__va(align_start), align_size);
+ kasan_remove_zero_shadow(__va(res->start), resource_size(res));
err_kasan:
- untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
+ untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
err_pfn_remap:
pgmap_array_delete(res);
err_array:
_