[PATCH v8 48/70] perf: use VMA iterator

Liam Howlett liam.howlett at oracle.com
Tue Apr 26 08:06:45 PDT 2022


From: "Matthew Wilcox (Oracle)" <willy at infradead.org>

The VMA iterator is faster than the linked list and removing the linked
list will shrink the vm_area_struct.

Signed-off-by: Matthew Wilcox (Oracle) <willy at infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
Acked-by: Vlastimil Babka <vbabka at suse.cz>
---
 kernel/events/core.c    | 3 ++-
 kernel/events/uprobes.c | 9 ++++++---
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 23bb19716ad3..b20b14d8dba7 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -10211,8 +10211,9 @@ static void perf_addr_filter_apply(struct perf_addr_filter *filter,
 				   struct perf_addr_filter_range *fr)
 {
 	struct vm_area_struct *vma;
+	VMA_ITERATOR(vmi, mm, 0);
 
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		if (!vma->vm_file)
 			continue;
 
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 4ef5385815d3..c3b2f695cc74 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -349,9 +349,10 @@ static bool valid_ref_ctr_vma(struct uprobe *uprobe,
 static struct vm_area_struct *
 find_ref_ctr_vma(struct uprobe *uprobe, struct mm_struct *mm)
 {
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *tmp;
 
-	for (tmp = mm->mmap; tmp; tmp = tmp->vm_next)
+	for_each_vma(vmi, tmp)
 		if (valid_ref_ctr_vma(uprobe, tmp))
 			return tmp;
 
@@ -1230,11 +1231,12 @@ int uprobe_apply(struct inode *inode, loff_t offset,
 
 static int unapply_uprobe(struct uprobe *uprobe, struct mm_struct *mm)
 {
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 	int err = 0;
 
 	mmap_read_lock(mm);
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		unsigned long vaddr;
 		loff_t offset;
 
@@ -1982,9 +1984,10 @@ bool uprobe_deny_signal(void)
 
 static void mmf_recalc_uprobes(struct mm_struct *mm)
 {
+	VMA_ITERATOR(vmi, mm, 0);
 	struct vm_area_struct *vma;
 
-	for (vma = mm->mmap; vma; vma = vma->vm_next) {
+	for_each_vma(vmi, vma) {
 		if (!valid_vma(vma, false))
 			continue;
 		/*
-- 
2.35.1



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