Messages in this thread Patch in this message | | | From | Qiujun Huang <> | Subject | [PATCH] ring-buffer: Add rb_check_bpage in __rb_allocate_pages | Date | Wed, 14 Oct 2020 23:16:14 +0800 |
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It may be better to check each page is aligned by 4 bytes. The 2 least significant bits of the address will be used as flags.
Signed-off-by: Qiujun Huang <hqjagain@gmail.com> --- kernel/trace/ring_buffer.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 93ef0ab6ea20..9dec7d58b177 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1420,7 +1420,8 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) return 0; } -static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) +static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, + long nr_pages, struct list_head *pages, int cpu) { struct buffer_page *bpage, *tmp; bool user_thread = current->mm != NULL; @@ -1464,6 +1465,8 @@ static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) if (!bpage) goto free_pages; + rb_check_bpage(cpu_buffer, bpage); + list_add(&bpage->list, pages); page = alloc_pages_node(cpu_to_node(cpu), mflags, 0); @@ -1498,7 +1501,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, WARN_ON(!nr_pages); - if (__rb_allocate_pages(nr_pages, &pages, cpu_buffer->cpu)) + if (__rb_allocate_pages(cpu_buffer, nr_pages, &pages, cpu_buffer->cpu)) return -ENOMEM; /* @@ -2007,7 +2010,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, * allocated without receiving ENOMEM */ INIT_LIST_HEAD(&cpu_buffer->new_pages); - if (__rb_allocate_pages(cpu_buffer->nr_pages_to_update, + if (__rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update, &cpu_buffer->new_pages, cpu)) { /* not enough memory for new pages */ err = -ENOMEM; @@ -2073,7 +2076,7 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, INIT_LIST_HEAD(&cpu_buffer->new_pages); if (cpu_buffer->nr_pages_to_update > 0 && - __rb_allocate_pages(cpu_buffer->nr_pages_to_update, + __rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update, &cpu_buffer->new_pages, cpu_id)) { err = -ENOMEM; goto out_err; -- 2.17.1
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