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-rw-r--r--kernel/trace/ring_buffer.c48
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;
}