+ mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch added to -mm tree

* + mm-introduce-pageflags_mask-to-replace-1ul-nr_pageflags-1.patch added to -mm tree
@ 2021-08-17 20:36 akpm
  0 siblings, 0 replies; 2+ messages in thread
From: akpm @ 2021-08-17 20:36 UTC (permalink / raw)
  To: mm-commits, songmuchun


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

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Muchun Song <songmuchun@bytedance.com>
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/20210817033032.76089-1-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@bytedance.com 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


^ permalink raw reply	[flat|nested] 2+ messages in thread