[PATCH 2/4] ring-buffer: Use kvzalloc_objs for remote buffer subbuf_ids
From: Vincent Donnefort <hidden>
Date: 2026-09-22 07:29:57
Also in:
lkml
Subsystem:
the rest, tracing · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Creating a remote ring buffer requires allocating an array of bpage. For large ring buffers, this contiguous allocation is likely to fail with memory fragmentation. Switch it to kvzalloc_objs() to use the vmalloc fallback under memory pressure. Signed-off-by: Vincent Donnefort <redacted> --- kernel/trace/ring_buffer.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f9be87c2cc3d..1a158a24b3c8 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c@@ -2620,8 +2620,8 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, unsigned long nr_pages, int cpu_buffer->remote = buffer->remote; cpu_buffer->meta_page = (struct trace_buffer_meta *)(void *)desc->meta_va; cpu_buffer->nr_pages = nr_pages; - cpu_buffer->subbuf_ids = kzalloc_objs(*cpu_buffer->subbuf_ids, - cpu_buffer->nr_pages + 1); + cpu_buffer->subbuf_ids = kvzalloc_objs(*cpu_buffer->subbuf_ids, + cpu_buffer->nr_pages + 1); if (!cpu_buffer->subbuf_ids) goto fail_free_reader;
@@ -2681,7 +2681,7 @@ rb_allocate_cpu_buffer(struct trace_buffer *buffer, unsigned long nr_pages, int return_ptr(cpu_buffer); fail_free_reader: - kfree(cpu_buffer->subbuf_ids); + kvfree(cpu_buffer->subbuf_ids); free_buffer_page(cpu_buffer->reader_page); return NULL;
@@ -2694,8 +2694,8 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) irq_work_sync(&cpu_buffer->irq_work.work); - if (cpu_buffer->remote) - kfree(cpu_buffer->subbuf_ids); + kvfree(cpu_buffer->subbuf_ids); + cpu_buffer->subbuf_ids = NULL; free_buffer_page(cpu_buffer->reader_page);
--
2.55.0.1082.g2b9226bbc0-goog