X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_backend.c;h=d4bec25ff956bfc21bc9c184b8230ca2963cbabc;hb=7502f47afaf537bbb67050b17ea095bb3976bf91;hp=9d199e516aacbaf009538faf394671113e18bf70;hpb=5f14d8ae2cc0734b007c8770c3b13ff00d830040;p=lttng-modules.git

diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c
index 9d199e51..d4bec25f 100644
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -16,6 +16,7 @@
 #include <linux/mm.h>
 #include <linux/vmalloc.h>
 
+#include <wrapper/mm.h>
 #include <wrapper/vmalloc.h>	/* for wrapper_vmalloc_sync_all() */
 #include <wrapper/ringbuffer/config.h>
 #include <wrapper/ringbuffer/backend.h>
@@ -43,6 +44,25 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	unsigned long i;
 
 	num_pages = size >> PAGE_SHIFT;
+
+	/*
+	 * Verify that there is enough free pages available on the system for
+	 * the current allocation request.
+	 * wrapper_check_enough_free_pages uses si_mem_available() if available
+	 * and returns if there should be enough free pages based on the
+	 * current estimate.
+	 */
+	if (!wrapper_check_enough_free_pages(num_pages))
+		goto not_enough_pages;
+
+	/*
+	 * Set the current user thread as the first target of the OOM killer.
+	 * If the estimate received by si_mem_available() was off, and we do
+	 * end up running out of memory because of this buffer allocation, we
+	 * want to kill the offending app first.
+	 */
+	wrapper_set_current_oom_origin();
+
 	num_pages_per_subbuf = num_pages >> get_count_order(num_subbuf);
 	subbuf_size = chanb->subbuf_size;
 	num_subbuf_alloc = num_subbuf;
@@ -137,6 +157,7 @@ int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config
 	 * will not fault.
 	 */
 	wrapper_vmalloc_sync_all();
+	wrapper_clear_current_oom_origin();
 	vfree(pages);
 	return 0;
 
@@ -153,6 +174,8 @@ depopulate:
 array_error:
 	vfree(pages);
 pages_error:
+	wrapper_clear_current_oom_origin();
+not_enough_pages:
 	return -ENOMEM;
 }