diff options
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r-- | kernel/trace/ring_buffer.c | 48 |
1 files changed, 38 insertions, 10 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 966128f02121..c9cb9767d49b 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -22,6 +22,7 @@ #include <linux/hash.h> #include <linux/list.h> #include <linux/cpu.h> +#include <linux/oom.h> #include <asm/local.h> @@ -1162,35 +1163,60 @@ static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) static int __rb_allocate_pages(long nr_pages, struct list_head *pages, int cpu) { struct buffer_page *bpage, *tmp; + bool user_thread = current->mm != NULL; + gfp_t mflags; long i; - /* Check if the available memory is there first */ + /* + * Check if the available memory is there first. + * Note, si_mem_available() only gives us a rough estimate of available + * memory. It may not be accurate. But we don't care, we just want + * to prevent doing any allocation when it is obvious that it is + * not going to succeed. + */ i = si_mem_available(); if (i < nr_pages) return -ENOMEM; + /* + * __GFP_RETRY_MAYFAIL flag makes sure that the allocation fails + * gracefully without invoking oom-killer and the system is not + * destabilized. + */ + mflags = GFP_KERNEL | __GFP_RETRY_MAYFAIL; + + /* + * If a user thread allocates too much, and si_mem_available() + * reports there's enough memory, even though there is not. + * Make sure the OOM killer kills this thread. This can happen + * even with RETRY_MAYFAIL because another task may be doing + * an allocation after this task has taken all memory. + * This is the task the OOM killer needs to take out during this + * loop, even if it was triggered by an allocation somewhere else. + */ + if (user_thread) + set_current_oom_origin(); for (i = 0; i < nr_pages; i++) { struct page *page; - /* - * __GFP_RETRY_MAYFAIL flag makes sure that the allocation fails - * gracefully without invoking oom-killer and the system is not - * destabilized. - */ + bpage = kzalloc_node(ALIGN(sizeof(*bpage), cache_line_size()), - GFP_KERNEL | __GFP_RETRY_MAYFAIL, - cpu_to_node(cpu)); + mflags, cpu_to_node(cpu)); if (!bpage) goto free_pages; list_add(&bpage->list, pages); - page = alloc_pages_node(cpu_to_node(cpu), - GFP_KERNEL | __GFP_RETRY_MAYFAIL, 0); + page = alloc_pages_node(cpu_to_node(cpu), mflags, 0); if (!page) goto free_pages; bpage->page = page_address(page); rb_init_page(bpage->page); + + if (user_thread && fatal_signal_pending(current)) + goto free_pages; } + if (user_thread) + clear_current_oom_origin(); return 0; @@ -1199,6 +1225,8 @@ free_pages: list_del_init(&bpage->list); free_buffer_page(bpage); } + if (user_thread) + clear_current_oom_origin(); return -ENOMEM; } |