[patch 233/262] mm/damon/vaddr: separate commonly usable functions

Andrew Morton
2021-11-05T20:46:56Z

From: SeongJae Park <sj@kernel.org>
Subject: mm/damon/vaddr: separate commonly usable functions

This commit moves functions in the default virtual address spaces
monitoring primitives that commonly usable from other address spaces like
physical address space into a header file. Those will be reused by the
physical address space monitoring primitives which will be implemented by
the following commit.

[sj@kernel.org: include 'highmem.h' to fix a build failure]
Link: https://lkml.kernel.org/r/20211014110848.5204-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20211012205711.29216-5-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

mm/damon/Makefile | 2
mm/damon/prmtv-common.c | 87 +++++++++++++++++++++++++++++++++++++
mm/damon/prmtv-common.h | 17 +++++++
mm/damon/vaddr.c | 88 +-------------------------------------
4 files changed, 108 insertions(+), 86 deletions(-)

--- a/mm/damon/Makefile~mm-damon-vaddr-separate-commonly-usable-functions
+++ a/mm/damon/Makefile
@@ -1,5 +1,5 @@
# SPDX-License-Identifier: GPL-2.0

obj-$(CONFIG_DAMON) := core.o
-obj-$(CONFIG_DAMON_VADDR) += vaddr.o
+obj-$(CONFIG_DAMON_VADDR) += prmtv-common.o vaddr.o
obj-$(CONFIG_DAMON_DBGFS) += dbgfs.o
--- /dev/null
+++ a/mm/damon/prmtv-common.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Common Primitives for Data Access Monitoring
+ *
+ * Author: SeongJae Park <sj@kernel.org>
+ */
+
+#include <linux/mmu_notifier.h>
+#include <linux/page_idle.h>
+#include <linux/pagemap.h>
+#include <linux/rmap.h>
+
+#include "prmtv-common.h"
+
+/*
+ * Get an online page for a pfn if it's in the LRU list. Otherwise, returns
+ * NULL.
+ *
+ * The body of this function is stolen from the 'page_idle_get_page()'. We
+ * steal rather than reuse it because the code is quite simple.
+ */
+struct page *damon_get_page(unsigned long pfn)
+{
+ struct page *page = pfn_to_online_page(pfn);
+
+ if (!page || !PageLRU(page) || !get_page_unless_zero(page))
+ return NULL;
+
+ if (unlikely(!PageLRU(page))) {
+ put_page(page);
+ page = NULL;
+ }
+ return page;
+}
+
+void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr)
+{
+ bool referenced = false;
+ struct page *page = damon_get_page(pte_pfn(*pte));
+
+ if (!page)
+ return;
+
+ if (pte_young(*pte)) {
+ referenced = true;
+ *pte = pte_mkold(*pte);
+ }
+
+#ifdef CONFIG_MMU_NOTIFIER
+ if (mmu_notifier_clear_young(mm, addr, addr + PAGE_SIZE))
+ referenced = true;
+#endif /* CONFIG_MMU_NOTIFIER */
+
+ if (referenced)
+ set_page_young(page);
+
+ set_page_idle(page);
+ put_page(page);
+}
+
+void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ bool referenced = false;
+ struct page *page = damon_get_page(pmd_pfn(*pmd));
+
+ if (!page)
+ return;
+
+ if (pmd_young(*pmd)) {
+ referenced = true;
+ *pmd = pmd_mkold(*pmd);
+ }
+
+#ifdef CONFIG_MMU_NOTIFIER
+ if (mmu_notifier_clear_young(mm, addr,
+ addr + ((1UL) << HPAGE_PMD_SHIFT)))
+ referenced = true;
+#endif /* CONFIG_MMU_NOTIFIER */
+
+ if (referenced)
+ set_page_young(page);
+
+ set_page_idle(page);
+ put_page(page);
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+}
--- /dev/null
+++ a/mm/damon/prmtv-common.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Common Primitives for Data Access Monitoring
+ *
+ * Author: SeongJae Park <sj@kernel.org>
+ */
+
+#include <linux/damon.h>
+#include <linux/random.h>
+
+/* Get a random number in [l, r) */
+#define damon_rand(l, r) (l + prandom_u32_max(r - l))
+
+struct page *damon_get_page(unsigned long pfn);
+
+void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm, unsigned long addr);
+void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm, unsigned long addr);
--- a/mm/damon/vaddr.c~mm-damon-vaddr-separate-commonly-usable-functions
+++ a/mm/damon/vaddr.c
@@ -8,25 +8,19 @@
#define pr_fmt(fmt) "damon-va: " fmt

#include <asm-generic/mman-common.h>
-#include <linux/damon.h>
+#include <linux/highmem.h>
#include <linux/hugetlb.h>
-#include <linux/mm.h>
#include <linux/mmu_notifier.h>
-#include <linux/highmem.h>
#include <linux/page_idle.h>
#include <linux/pagewalk.h>
-#include <linux/random.h>
-#include <linux/sched/mm.h>
-#include <linux/slab.h>
+
+#include "prmtv-common.h"

#ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
#undef DAMON_MIN_REGION
#define DAMON_MIN_REGION 1
#endif

-/* Get a random number in [l, r) */
-#define damon_rand(l, r) (l + prandom_u32_max(r - l))
-
/*
* 't->id' should be the pointer to the relevant 'struct pid' having reference
* count. Caller must put the returned task, unless it is NULL.
@@ -373,82 +367,6 @@ void damon_va_update(struct damon_ctx *c
}
}

-/*
- * Get an online page for a pfn if it's in the LRU list. Otherwise, returns
- * NULL.
- *
- * The body of this function is stolen from the 'page_idle_get_page()'. We
- * steal rather than reuse it because the code is quite simple.
- */
-static struct page *damon_get_page(unsigned long pfn)
-{
- struct page *page = pfn_to_online_page(pfn);
-
- if (!page || !PageLRU(page) || !get_page_unless_zero(page))
- return NULL;
-
- if (unlikely(!PageLRU(page))) {
- put_page(page);
- page = NULL;
- }
- return page;
-}
-
-static void damon_ptep_mkold(pte_t *pte, struct mm_struct *mm,
- unsigned long addr)
-{
- bool referenced = false;
- struct page *page = damon_get_page(pte_pfn(*pte));
-
- if (!page)
- return;
-
- if (pte_young(*pte)) {
- referenced = true;
- *pte = pte_mkold(*pte);
- }
-
-#ifdef CONFIG_MMU_NOTIFIER
- if (mmu_notifier_clear_young(mm, addr, addr + PAGE_SIZE))
- referenced = true;
-#endif /* CONFIG_MMU_NOTIFIER */
-
- if (referenced)
- set_page_young(page);
-
- set_page_idle(page);
- put_page(page);
-}
-
-static void damon_pmdp_mkold(pmd_t *pmd, struct mm_struct *mm,
- unsigned long addr)
-{
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
- bool referenced = false;
- struct page *page = damon_get_page(pmd_pfn(*pmd));
-
- if (!page)
- return;
-
- if (pmd_young(*pmd)) {
- referenced = true;
- *pmd = pmd_mkold(*pmd);
- }
-
-#ifdef CONFIG_MMU_NOTIFIER
- if (mmu_notifier_clear_young(mm, addr,
- addr + ((1UL) << HPAGE_PMD_SHIFT)))
- referenced = true;
-#endif /* CONFIG_MMU_NOTIFIER */
-
- if (referenced)
- set_page_young(page);
-
- set_page_idle(page);
- put_page(page);
-#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-}
-
static int damon_mkold_pmd_entry(pmd_t *pmd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
_