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Date: Wed, 26 Jan 2022 18:34:27 +0000
From: Pasha Tatashin <pasha.tatashin@...een.com>
To: pasha.tatashin@...een.com, linux-kernel@...r.kernel.org,
linux-mm@...ck.org, linux-m68k@...ts.linux-m68k.org,
anshuman.khandual@....com, willy@...radead.org,
akpm@...ux-foundation.org, william.kucharski@...cle.com,
mike.kravetz@...cle.com, vbabka@...e.cz, geert@...ux-m68k.org,
schmitzmic@...il.com, rostedt@...dmis.org, mingo@...hat.com,
hannes@...xchg.org, guro@...com, songmuchun@...edance.com,
weixugc@...gle.com, gthelen@...gle.com, rientjes@...gle.com,
pjt@...gle.com, hughd@...gle.com
Subject: [PATCH v3 7/9] mm: simplify page_ref_* functions
Now, that we are using atomic_fetch* variants to add/sub/inc/dec page
_refcount, it makes sense to combined page_ref_* return and non return
functions.
Also remove some extra trace points for non-return variants. This
improves the tracability by always recording the new _refcount value
after the modifications has occurred.
Signed-off-by: Pasha Tatashin <pasha.tatashin@...een.com>
---
include/linux/page_ref.h | 102 +++++++++-----------------------
include/trace/events/page_ref.h | 18 +-----
mm/debug_page_ref.c | 14 -----
3 files changed, 31 insertions(+), 103 deletions(-)
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h
index d7316881626c..243fc60ae6c8 100644
--- a/include/linux/page_ref.h
+++ b/include/linux/page_ref.h
@@ -8,8 +8,6 @@
#include <linux/tracepoint-defs.h>
DECLARE_TRACEPOINT(page_ref_init);
-DECLARE_TRACEPOINT(page_ref_mod);
-DECLARE_TRACEPOINT(page_ref_mod_and_test);
DECLARE_TRACEPOINT(page_ref_mod_and_return);
DECLARE_TRACEPOINT(page_ref_mod_unless);
DECLARE_TRACEPOINT(page_ref_freeze);
@@ -27,8 +25,6 @@ DECLARE_TRACEPOINT(page_ref_unfreeze);
#define page_ref_tracepoint_active(t) tracepoint_enabled(t)
extern void __page_ref_init(struct page *page);
-extern void __page_ref_mod(struct page *page, int v);
-extern void __page_ref_mod_and_test(struct page *page, int v, int ret);
extern void __page_ref_mod_and_return(struct page *page, int v, int ret);
extern void __page_ref_mod_unless(struct page *page, int v, int u);
extern void __page_ref_freeze(struct page *page, int v, int ret);
@@ -41,12 +37,6 @@ extern void __page_ref_unfreeze(struct page *page, int v);
static inline void __page_ref_init(struct page *page)
{
}
-static inline void __page_ref_mod(struct page *page, int v)
-{
-}
-static inline void __page_ref_mod_and_test(struct page *page, int v, int ret)
-{
-}
static inline void __page_ref_mod_and_return(struct page *page, int v, int ret)
{
}
@@ -127,12 +117,7 @@ static inline int page_ref_add_return(struct page *page, int nr)
static inline void page_ref_add(struct page *page, int nr)
{
- int old_val = atomic_fetch_add(nr, &page->_refcount);
- int new_val = old_val + nr;
-
- VM_BUG_ON_PAGE((unsigned int)new_val < (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod))
- __page_ref_mod(page, nr);
+ page_ref_add_return(page, nr);
}
static inline void folio_ref_add(struct folio *folio, int nr)
@@ -140,30 +125,25 @@ static inline void folio_ref_add(struct folio *folio, int nr)
page_ref_add(&folio->page, nr);
}
-static inline void page_ref_sub(struct page *page, int nr)
+static inline int page_ref_sub_return(struct page *page, int nr)
{
int old_val = atomic_fetch_sub(nr, &page->_refcount);
int new_val = old_val - nr;
VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod))
- __page_ref_mod(page, -nr);
+ if (page_ref_tracepoint_active(page_ref_mod_and_return))
+ __page_ref_mod_and_return(page, -nr, new_val);
+ return new_val;
}
-static inline void folio_ref_sub(struct folio *folio, int nr)
+static inline void page_ref_sub(struct page *page, int nr)
{
- page_ref_sub(&folio->page, nr);
+ page_ref_sub_return(page, nr);
}
-static inline int page_ref_sub_return(struct page *page, int nr)
+static inline void folio_ref_sub(struct folio *folio, int nr)
{
- int old_val = atomic_fetch_sub(nr, &page->_refcount);
- int new_val = old_val - nr;
-
- VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod_and_return))
- __page_ref_mod_and_return(page, -nr, new_val);
- return new_val;
+ page_ref_sub(&folio->page, nr);
}
static inline int folio_ref_sub_return(struct folio *folio, int nr)
@@ -171,14 +151,20 @@ static inline int folio_ref_sub_return(struct folio *folio, int nr)
return page_ref_sub_return(&folio->page, nr);
}
-static inline void page_ref_inc(struct page *page)
+static inline int page_ref_inc_return(struct page *page)
{
int old_val = atomic_fetch_inc(&page->_refcount);
int new_val = old_val + 1;
VM_BUG_ON_PAGE((unsigned int)new_val < (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod))
- __page_ref_mod(page, 1);
+ if (page_ref_tracepoint_active(page_ref_mod_and_return))
+ __page_ref_mod_and_return(page, 1, new_val);
+ return new_val;
+}
+
+static inline void page_ref_inc(struct page *page)
+{
+ page_ref_inc_return(page);
}
static inline void folio_ref_inc(struct folio *folio)
@@ -186,14 +172,20 @@ static inline void folio_ref_inc(struct folio *folio)
page_ref_inc(&folio->page);
}
-static inline void page_ref_dec(struct page *page)
+static inline int page_ref_dec_return(struct page *page)
{
int old_val = atomic_fetch_dec(&page->_refcount);
int new_val = old_val - 1;
VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod))
- __page_ref_mod(page, -1);
+ if (page_ref_tracepoint_active(page_ref_mod_and_return))
+ __page_ref_mod_and_return(page, -1, new_val);
+ return new_val;
+}
+
+static inline void page_ref_dec(struct page *page)
+{
+ page_ref_dec_return(page);
}
static inline void folio_ref_dec(struct folio *folio)
@@ -203,14 +195,7 @@ static inline void folio_ref_dec(struct folio *folio)
static inline int page_ref_sub_and_test(struct page *page, int nr)
{
- int old_val = atomic_fetch_sub(nr, &page->_refcount);
- int new_val = old_val - nr;
- int ret = new_val == 0;
-
- VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod_and_test))
- __page_ref_mod_and_test(page, -nr, ret);
- return ret;
+ return page_ref_sub_return(page, nr) == 0;
}
static inline int folio_ref_sub_and_test(struct folio *folio, int nr)
@@ -218,17 +203,6 @@ static inline int folio_ref_sub_and_test(struct folio *folio, int nr)
return page_ref_sub_and_test(&folio->page, nr);
}
-static inline int page_ref_inc_return(struct page *page)
-{
- int old_val = atomic_fetch_inc(&page->_refcount);
- int new_val = old_val + 1;
-
- VM_BUG_ON_PAGE((unsigned int)new_val < (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod_and_return))
- __page_ref_mod_and_return(page, 1, new_val);
- return new_val;
-}
-
static inline int folio_ref_inc_return(struct folio *folio)
{
return page_ref_inc_return(&folio->page);
@@ -236,14 +210,7 @@ static inline int folio_ref_inc_return(struct folio *folio)
static inline int page_ref_dec_and_test(struct page *page)
{
- int old_val = atomic_fetch_dec(&page->_refcount);
- int new_val = old_val - 1;
- int ret = new_val == 0;
-
- VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod_and_test))
- __page_ref_mod_and_test(page, -1, ret);
- return ret;
+ return page_ref_dec_return(page) == 0;
}
static inline int folio_ref_dec_and_test(struct folio *folio)
@@ -251,17 +218,6 @@ static inline int folio_ref_dec_and_test(struct folio *folio)
return page_ref_dec_and_test(&folio->page);
}
-static inline int page_ref_dec_return(struct page *page)
-{
- int old_val = atomic_fetch_dec(&page->_refcount);
- int new_val = old_val - 1;
-
- VM_BUG_ON_PAGE((unsigned int)new_val > (unsigned int)old_val, page);
- if (page_ref_tracepoint_active(page_ref_mod_and_return))
- __page_ref_mod_and_return(page, -1, new_val);
- return new_val;
-}
-
static inline int folio_ref_dec_return(struct folio *folio)
{
return page_ref_dec_return(&folio->page);
diff --git a/include/trace/events/page_ref.h b/include/trace/events/page_ref.h
index 87551bb1df9e..35cd795aa7c6 100644
--- a/include/trace/events/page_ref.h
+++ b/include/trace/events/page_ref.h
@@ -49,7 +49,7 @@ DEFINE_EVENT(page_ref_init_template, page_ref_init,
TP_ARGS(page)
);
-DECLARE_EVENT_CLASS(page_ref_mod_template,
+DECLARE_EVENT_CLASS(page_ref_unfreeze_template,
TP_PROTO(struct page *page, int v),
@@ -83,13 +83,6 @@ DECLARE_EVENT_CLASS(page_ref_mod_template,
__entry->val)
);
-DEFINE_EVENT(page_ref_mod_template, page_ref_mod,
-
- TP_PROTO(struct page *page, int v),
-
- TP_ARGS(page, v)
-);
-
DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
TP_PROTO(struct page *page, int v, int ret),
@@ -126,13 +119,6 @@ DECLARE_EVENT_CLASS(page_ref_mod_and_test_template,
__entry->val, __entry->ret)
);
-DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_test,
-
- TP_PROTO(struct page *page, int v, int ret),
-
- TP_ARGS(page, v, ret)
-);
-
DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_mod_and_return,
TP_PROTO(struct page *page, int v, int ret),
@@ -154,7 +140,7 @@ DEFINE_EVENT(page_ref_mod_and_test_template, page_ref_freeze,
TP_ARGS(page, v, ret)
);
-DEFINE_EVENT(page_ref_mod_template, page_ref_unfreeze,
+DEFINE_EVENT(page_ref_unfreeze_template, page_ref_unfreeze,
TP_PROTO(struct page *page, int v),
diff --git a/mm/debug_page_ref.c b/mm/debug_page_ref.c
index e32149734122..1de9d93cca25 100644
--- a/mm/debug_page_ref.c
+++ b/mm/debug_page_ref.c
@@ -12,20 +12,6 @@ void __page_ref_init(struct page *page)
EXPORT_SYMBOL(__page_ref_init);
EXPORT_TRACEPOINT_SYMBOL(page_ref_init);
-void __page_ref_mod(struct page *page, int v)
-{
- trace_page_ref_mod(page, v);
-}
-EXPORT_SYMBOL(__page_ref_mod);
-EXPORT_TRACEPOINT_SYMBOL(page_ref_mod);
-
-void __page_ref_mod_and_test(struct page *page, int v, int ret)
-{
- trace_page_ref_mod_and_test(page, v, ret);
-}
-EXPORT_SYMBOL(__page_ref_mod_and_test);
-EXPORT_TRACEPOINT_SYMBOL(page_ref_mod_and_test);
-
void __page_ref_mod_and_return(struct page *page, int v, int ret)
{
trace_page_ref_mod_and_return(page, v, ret);
--
2.35.0.rc0.227.g00780c9af4-goog
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