From: Bob Glossman <bob.glossman@intel.com>
Date: Tue, 24 May 2016 18:16:35 +0000 (-0700)
Subject: LU-8196 obd: force very large allocations to use vmalloc
X-Git-Tag: 2.8.55~23
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=5b8749c4669e93dcafebc4c93aa1974c96ff43c7

LU-8196 obd: force very large allocations to use vmalloc

In cases where the requsted allocation size is very large
use OBD_VMALLOC().  This avoids warnings from el7 and newer
kernels due to very large kmalloc()s.

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I87e95b1f8e5e50bc35d713a1775313c10f0368a9
Reviewed-on: http://review.whamcloud.com/20420
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lustre/include/obd_support.h b/lustre/include/obd_support.h
index f089bf3..81a32c7 100644
--- a/lustre/include/obd_support.h
+++ b/lustre/include/obd_support.h
@@ -749,7 +749,11 @@ do {									      \
 
 #define OBD_ALLOC_LARGE(ptr, size)                                            \
 do {                                                                          \
-	OBD_ALLOC_GFP(ptr, size, GFP_NOFS | __GFP_NOWARN);                    \
+	/* LU-8196 - force large allocations to use vmalloc, not kmalloc */   \
+	if ((size) > KMALLOC_MAX_SIZE)                                          \
+		ptr = NULL;                                                   \
+	else                                                                  \
+		OBD_ALLOC_GFP(ptr, size, GFP_NOFS | __GFP_NOWARN);            \
 	if (ptr == NULL)                                                      \
                 OBD_VMALLOC(ptr, size);                                       \
 } while (0)