[PATCH] add OOM debug

This patch provides more debug info when the system is OOM.  It displays
memory stats (basically sysrq-m info) from __alloc_pages() when page
allocation fails and during OOM kill.

Thanks to Dave Jones for coming up with the idea.

Signed-off-by: Janet Morgan <janetmor@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 4bbb1cb..59666d9 100644 (file)
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -258,6 +258,10 @@ void out_of_memory(unsigned int __nocast gfp_mask)
        struct mm_struct *mm = NULL;
        task_t * p;
 
+       printk("oom-killer: gfp_mask=0x%x\n", gfp_mask);
+       /* print memory stats */
+       show_mem();
+
        read_lock(&tasklist_lock);
 retry:
        p = select_bad_process();
@@ -268,12 +272,9 @@ retry:
        /* Found nothing?!?! Either we hang forever, or we panic. */
        if (!p) {
                read_unlock(&tasklist_lock);
-               show_free_areas();
                panic("Out of memory and no killable processes...\n");
        }
 
-       printk("oom-killer: gfp_mask=0x%x\n", gfp_mask);
-       show_free_areas();
        mm = oom_kill_process(p);
        if (!mm)
                goto retry;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 10446a6..be05d17 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -935,6 +935,7 @@ nopage:
                        " order:%d, mode:0x%x\n",
                        p->comm, order, gfp_mask);
                dump_stack();
+               show_mem();
        }
        return NULL;
 got_pg: