On 04.09.24 04:02, Zi Yan wrote:
On 2 Sep 2024, at 12:42, David Hildenbrand wrote:
On 02.09.24 17:34, Zi Yan wrote:
On 2 Sep 2024, at 5:06, David Hildenbrand wrote:
On 28.08.24 22:22, Zi Yan wrote:
migratetype is no longer overwritten during pageblock isolation,
start_isolate_page_range(), has_unmovable_pages(), and
set_migratetype_isolate() no longer need which migratetype to restore
during isolation failure. For has_unmoable_pages(), it needs to know if
the isolation is for CMA allocation, so adding CMA_ALLOCATION to isolation
flags to provide the information.
Signed-off-by: Zi Yan <ziy@xxxxxxxxxx>
---
include/linux/page-isolation.h | 3 ++-
mm/memory_hotplug.c | 1 -
mm/page_alloc.c | 4 +++-
mm/page_isolation.c | 27 +++++++++++----------------
4 files changed, 16 insertions(+), 19 deletions(-)
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index c2a1bd621561..e94117101b6c 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -32,13 +32,14 @@ static inline bool is_migrate_isolate(int migratetype)
#define MEMORY_OFFLINE 0x1
#define REPORT_FAILURE 0x2
+#define CMA_ALLOCATION 0x4
void set_pageblock_migratetype(struct page *page, int migratetype);
bool move_freepages_block_isolate(struct zone *zone, struct page *page);
int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn,
- int migratetype, int flags, gfp_t gfp_flags);
+ int flags, gfp_t gfp_flags);
void undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 4265272faf4c..fe0b71e0f307 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1993,7 +1993,6 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages,
/* set above range as isolated */
ret = start_isolate_page_range(start_pfn, end_pfn,
- MIGRATE_MOVABLE,
MEMORY_OFFLINE | REPORT_FAILURE,
GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL);
if (ret) {
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4d06932ba69a..c60bb95d7e65 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -6607,7 +6607,9 @@ int alloc_contig_range_noprof(unsigned long start, unsigned long end,
* put back to page allocator so that buddy can use them.
*/
- ret = start_isolate_page_range(start, end, migratetype, 0, gfp_mask);
+ ret = start_isolate_page_range(start, end,
+ migratetype == MIGRATE_CMA ? CMA_ALLOCATION : 0,
Can we have flags for alloc_contig_range() instead of passing in a (weird) migratetype?
Then, we should make sure that we warn if we try a CMA allocation on any pageblock that is not of type CMA.
Sure. I will expose the existing isolation flags (MEMORY_OFFLINE, REPORT_FAILURE,
and CMA_ALLOCATION) as alloc_contig_range() parameter to replace migratetype one.
Maybe we want some proper, distinct alloc_contig_range() falgs "acr_flags_t". Might be cleanest, to express anything that doesn't fall into the gfp_t flag category.
Exposing MEMORY_OFFLINE feels wrong, for example.
OK, it seems that I mixed up of start_isolate_page_range() flags with
alloc_contig_range() flags. Let me clarify them below.
For start_isolate_page_range(), memory offline calls it separately and
needs MEMORY_OFFLINE and REPORT_FAILURE; CMA allocation uses it via
alloc_contig_range() and needs a flag (like CMA_ALLOCATION) for its
own checks.
BTW, it seems to me that MEMORY_OFFLINE and REPORT_FAILURE can be merged,
since they are always used together. Let me know if you disagree.
I think there was a discussion about possibly using REPORT_FAILURE in
other cases, but I agree that we might just merge them at this point.
For alloc_contig_range(), migratetype parameter is what you are talking about
above. There are two callers: cma_alloc() and alloc_contig_pages().
The acr_flags_t is basically a caller id. Something like?
enum acr_flags_t {
ACR_CMA_ALLOC,
ACR_CONTIG_PAGES,
};
I'd do something like:
typedef unsigned int __bitwise acr_flags_t;
#define ACR_CMA ((__force acr_flags_t)BIT(0))
No need for "ACR_CONTIG_PAGES", it's implicit if the CMA flag is not set.
And ACR_CMA_ALLOC needs to be translated to CMA_ALLOCATION when
start_isolate_page_range() is called.
Yes.
BTW, after removing migratetype parameter from alloc_contig_range(),
the tracepoint in __alloc_contig_migrate_range() needs to be changed to
use acr_flags_t, since I do not think we want to convert acr_flags_t
back to migratetype.
Sure, feel free to modify these tracepoints as it suits you.
--
Cheers,
David / dhildenb
