Fix: implicit declarations caused by buffer size checks.

[lttng-modules.git] / lib / ringbuffer / ring_buffer_backend.c

diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c
index 9d199e516aacbaf009538faf394671113e18bf70..d4bec25ff956bfc21bc9c184b8230ca2963cbabc 100644 (file)
--- 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;
 }