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ring-buffer: Add rb_check_bpage in __rb_allocate_pages

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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.

Link: https://lkml.kernel.org/r/20201015113842.2921-1-hqjagain@gmail.com

Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Qiujun Huang 2020-10-15 19:38:42 +08:00 committed by Steven Rostedt (VMware)
parent 82db909e6b
commit 74e2afc6df
1 changed files with 11 additions and 8 deletions
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19
kernel/trace/ring_buffer.c
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@ -1423,7 +1423,8 @@ 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)
{
struct buffer_page *bpage, *tmp;
bool user_thread = current->mm != NULL;
@ -1463,13 +1464,15 @@ static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu)
struct page *page;
bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()),
mflags, cpu_to_node(cpu));
mflags, cpu_to_node(cpu_buffer->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);
page = alloc_pages_node(cpu_to_node(cpu_buffer->cpu), mflags, 0);
if (!page)
goto free_pages;
bpage->page = page_address(page);
@ -1501,7 +1504,7 @@ 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))
return -ENOMEM;
/*
@ -2008,8 +2011,8 @@ 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,
&cpu_buffer->new_pages, cpu)) {
if (__rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update,
&cpu_buffer->new_pages)) {
/* not enough memory for new pages */
err = -ENOMEM;
goto out_err;
@ -2074,8 +2077,8 @@ 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,
&cpu_buffer->new_pages, cpu_id)) {
__rb_allocate_pages(cpu_buffer, cpu_buffer->nr_pages_to_update,
&cpu_buffer->new_pages)) {
err = -ENOMEM;
goto out_err;
}