The patch titled
Subject: mm: introduce PAGEFLAGS_MASK to replace ((1UL << NR_PAGEFLAGS) - 1)
has been added to the -mm tree. Its filename is
mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch
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------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: introduce PAGEFLAGS_MASK to replace ((1UL << NR_PAGEFLAGS) - 1)
Instead of hard-coding ((1UL << NR_PAGEFLAGS) - 1) everywhere, introducing
PAGEFLAGS_MASK to make the code clear to get the page flags.
Link: https://lkml.kernel.org/r/20210819150712.59948-1-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Reviewed-by: Roman Gushchin <guro@xxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/page-flags.h | 4 +++-
include/trace/events/page_ref.h | 4 ++--
lib/test_printf.c | 2 +-
lib/vsprintf.c | 2 +-
4 files changed, 7 insertions(+), 5 deletions(-)
--- a/include/linux/page-flags.h~mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1
+++ a/include/linux/page-flags.h
@@ -178,6 +178,8 @@ enum pageflags {
PG_reported = PG_uptodate,
};
+#define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1)
+
#ifndef __GENERATING_BOUNDS_H
static inline unsigned long _compound_head(const struct page *page)
@@ -868,7 +870,7 @@ static inline void ClearPageSlabPfmemall
* alloc-free cycle to prevent from reusing the page.
*/
#define PAGE_FLAGS_CHECK_AT_PREP \
- (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON)
+ (PAGEFLAGS_MASK & ~__PG_HWPOISON)
#define PAGE_FLAGS_PRIVATE \
(1UL << PG_private | 1UL << PG_private_2)
--- a/include/trace/events/page_ref.h~mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1
+++ a/include/trace/events/page_ref.h
@@ -38,7 +38,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_templat
TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d",
__entry->pfn,
- show_page_flags(__entry->flags & ((1UL << NR_PAGEFLAGS) - 1)),
+ show_page_flags(__entry->flags & PAGEFLAGS_MASK),
__entry->count,
__entry->mapcount, __entry->mapping, __entry->mt,
__entry->val)
@@ -88,7 +88,7 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_tes
TP_printk("pfn=0x%lx flags=%s count=%d mapcount=%d mapping=%p mt=%d val=%d ret=%d",
__entry->pfn,
- show_page_flags(__entry->flags & ((1UL << NR_PAGEFLAGS) - 1)),
+ show_page_flags(__entry->flags & PAGEFLAGS_MASK),
__entry->count,
__entry->mapcount, __entry->mapping, __entry->mt,
__entry->val, __entry->ret)
--- a/lib/test_printf.c~mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1
+++ a/lib/test_printf.c
@@ -614,7 +614,7 @@ page_flags_test(int section, int node, i
bool append = false;
int i;
- flags &= BIT(NR_PAGEFLAGS) - 1;
+ flags &= PAGEFLAGS_MASK;
if (flags) {
page_flags |= flags;
snprintf(cmp_buf + size, BUF_SIZE - size, "%s", name);
--- a/lib/vsprintf.c~mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1
+++ a/lib/vsprintf.c
@@ -2019,7 +2019,7 @@ static const struct page_flags_fields pf
static
char *format_page_flags(char *buf, char *end, unsigned long flags)
{
- unsigned long main_flags = flags & (BIT(NR_PAGEFLAGS) - 1);
+ unsigned long main_flags = flags & PAGEFLAGS_MASK;
bool append = false;
int i;
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-bootmem_info-mark-__init-on-register_page_bootmem_info_section.patch
mm-remove-redundant-compound_head-calling.patch
mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch
