Re: [PATCH bpf-next] bpf: use VM_MAP instead of VM_ALLOC for ringbuf
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2022-01-31 16:29:14
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bpf
On 1/31/22 12:46 PM, Hou Tao wrote:
Now the ringbuf area in /proc/vmallocinfo is showed as vmalloc, but VM_ALLOC is only used for vmalloc(), and for the ringbuf area it is created by mapping allocated pages, so use VM_MAP instead. After the change, ringbuf info in /proc/vmallocinfo will changed from: [start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmalloc user to [start]-[end] 24576 ringbuf_map_alloc+0x171/0x290 vmap user
Could you elaborate in the commit msg if this also has some other internal effect aside from the /proc/vmallocinfo listing? Thanks!
quoted hunk ↗ jump to hunk
Signed-off-by: Hou Tao <redacted> --- kernel/bpf/ringbuf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index 638d7fd7b375..710ba9de12ce 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c@@ -104,7 +104,7 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node) } rb = vmap(pages, nr_meta_pages + 2 * nr_data_pages, - VM_ALLOC | VM_USERMAP, PAGE_KERNEL); + VM_MAP | VM_USERMAP, PAGE_KERNEL); if (rb) { kmemleak_not_leak(pages); rb->pages = pages;