The patch titled
Subject: mm/hugetlb: add folio_hstate()
has been added to the -mm mm-unstable branch. Its filename is
mm-hugetlb-add-folio_hstate.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-hugetlb-add-folio_hstate.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Subject: mm/hugetlb: add folio_hstate()
Date: Thu, 22 Sep 2022 10:42:07 -0500
Patch series "begin converting hugetlb code to folios", v4.
This patch series starts the conversion of the hugetlb code to operate on
struct folios rather than struct pages. This removes the ambiguitiy of
whether functions are operating on head pages, tail pages of compound
pages, or base pages.
This series passes the linux test project hugetlb test cases.
Patch 1 adds hugeltb specific page macros that can operate on folios.
Patch 2 adds the private field of the first tail page to struct page. For
32-bit, _private_1 alinging with page[1].private was confirmed by using
pahole.
Patch 3 introduces hugetlb subpool helper functions which operate on
struct folios. These patches were tested using the hugepage-mmap.c
selftest along with the migratepages command.
Patch 4 converts hugetlb_delete_from_page_cache() to use folios.
Patch 5 adds a folio_hstate() function to get hstate information from a
folio and adds a user of folio_hstate().
Bpftrace was used to track time spent in the free_huge_pages function
during the ltp test cases as it is a caller of the hugetlb subpool
functions. From the histogram, the performance is similar before and
after the patch series.
Time spent in 'free_huge_page'
6.0.0-rc2.master.20220823
@nsecs:
[256, 512) 14770 |@@@@@@@@@@@@@@@@@@@@@@@@@@@
|@@@@@@@@@@@@@@@@@@@@@@@@@ |
[512, 1K) 155 | |
[1K, 2K) 169 | |
[2K, 4K) 50 | |
[4K, 8K) 14 | |
[8K, 16K) 3 | |
[16K, 32K) 3 | |
6.0.0-rc2.master.20220823 + patch series
@nsecs:
[256, 512) 13678 |@@@@@@@@@@@@@@@@@@@@@@@@@@@ |
|@@@@@@@@@@@@@@@@@@@@@@@@@ |
[512, 1K) 142 | |
[1K, 2K) 199 | |
[2K, 4K) 44 | |
[4K, 8K) 13 | |
[8K, 16K) 4 | |
[16K, 32K) 1 | |
This patch (of 5):
Helper function to retrieve hstate information from a hugetlb folio.
Link: https://lkml.kernel.org/r/20220922154207.1575343-6-sidhartha.kumar@xxxxxxxxxx
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Colin Cross <ccross@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: "Eric W . Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: William Kucharski <william.kucharski@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/hugetlb.h | 14 ++++++++++++--
mm/migrate.c | 2 +-
2 files changed, 13 insertions(+), 3 deletions(-)
--- a/include/linux/hugetlb.h~mm-hugetlb-add-folio_hstate
+++ a/include/linux/hugetlb.h
@@ -824,10 +824,15 @@ static inline pte_t arch_make_huge_pte(p
}
#endif
+static inline struct hstate *folio_hstate(struct folio *folio)
+{
+ VM_BUG_ON_FOLIO(!folio_test_hugetlb(folio), folio);
+ return size_to_hstate(folio_size(folio));
+}
+
static inline struct hstate *page_hstate(struct page *page)
{
- VM_BUG_ON_PAGE(!PageHuge(page), page);
- return size_to_hstate(page_size(page));
+ return folio_hstate(page_folio(page));
}
static inline unsigned hstate_index_to_shift(unsigned index)
@@ -1035,6 +1040,11 @@ static inline struct hstate *hstate_vma(
{
return NULL;
}
+
+static inline struct hstate *folio_hstate(struct folio *folio)
+{
+ return NULL;
+}
static inline struct hstate *page_hstate(struct page *page)
{
--- a/mm/migrate.c~mm-hugetlb-add-folio_hstate
+++ a/mm/migrate.c
@@ -1613,7 +1613,7 @@ struct page *alloc_migration_target(stru
nid = folio_nid(folio);
if (folio_test_hugetlb(folio)) {
- struct hstate *h = page_hstate(&folio->page);
+ struct hstate *h = folio_hstate(folio);
gfp_mask = htlb_modify_alloc_mask(h, gfp_mask);
return alloc_huge_page_nodemask(h, nid, mtc->nmask, gfp_mask);
_
Patches currently in -mm which might be from sidhartha.kumar@xxxxxxxxxx are
mm-hugetlb-add-folio-support-to-hugetlb-specific-flag-macros.patch
mm-add-private-field-of-first-tail-to-struct-page-and-struct-folio.patch
mm-hugetlb-add-hugetlb_folio_subpool-helpers.patch
hugetlbfs-convert-hugetlb_delete_from_page_cache-to-use-folios.patch
mm-hugetlb-add-folio_hstate.patch
mm-hugetlb_cgroup-convert-__set_hugetlb_cgroup-to-folios.patch
mm-hugetlb_cgroup-convert-hugetlb_cgroup_from_page-to-folios.patch
mm-hugetlb_cgroup-convert-set_hugetlb_cgroup-to-folios.patch
mm-hugetlb_cgroup-convert-hugetlb_cgroup_migrate-to-folios.patch
mm-hugetlb-convert-isolate_or_dissolve_huge_page-to-folios.patch
mm-hugetlb-convert-free_huge_page-to-folios.patch
mm-hugetlb_cgroup-convert-hugetlb_cgroup_uncharge_page-to-folios.patch
mm-hugeltb_cgroup-convert-hugetlb_cgroup_commit_charge-to-folios.patch
mm-hugetlb-convert-move_hugetlb_state-to-folios.patch
