[PATCH v4 2/2] ftrace: Introduce and use ENTRIES_PER_PAGE_GROUP macro
From: Guenter Roeck
Date: Tue Jan 13 2026 - 10:22:49 EST
ENTRIES_PER_PAGE_GROUP() returns the number of dyn_ftrace entries in a page
group, identified by its order.
No functional change.
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
v4: New patch, optional. Squash, drop, or apply as separate patch.
kernel/trace/ftrace.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index aa758efc3731..df4ce244202e 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1148,6 +1148,7 @@ struct ftrace_page {
};
#define ENTRY_SIZE sizeof(struct dyn_ftrace)
+#define ENTRIES_PER_PAGE_GROUP(order) ((PAGE_SIZE << (order)) / ENTRY_SIZE)
static struct ftrace_page *ftrace_pages_start;
static struct ftrace_page *ftrace_pages;
@@ -3862,7 +3863,7 @@ static int ftrace_allocate_records(struct ftrace_page *pg, int count,
*num_pages += 1 << order;
ftrace_number_of_groups++;
- cnt = (PAGE_SIZE << order) / ENTRY_SIZE;
+ cnt = ENTRIES_PER_PAGE_GROUP(order);
pg->order = order;
if (cnt > count)
@@ -7309,7 +7310,7 @@ static int ftrace_process_locs(struct module *mod,
long skip;
/* Count the number of entries unused and compare it to skipped. */
- pg_remaining = (PAGE_SIZE << pg->order) / ENTRY_SIZE - pg->index;
+ pg_remaining = ENTRIES_PER_PAGE_GROUP(pg->order) - pg->index;
if (!WARN(skipped < pg_remaining, "Extra allocated pages for ftrace")) {
@@ -7317,7 +7318,7 @@ static int ftrace_process_locs(struct module *mod,
for (pg = pg_unuse; pg && skip > 0; pg = pg->next) {
remaining += 1 << pg->order;
- skip -= (PAGE_SIZE << pg->order) / ENTRY_SIZE;
+ skip -= ENTRIES_PER_PAGE_GROUP(pg->order);
}
pages -= remaining;
--
2.45.2