revert sg segment size ifdefs

This reverts sg segment size ifdefs that the current code has in order
to provide a way to reduce sgpool memory consumption.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 20 insertions, 8 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b6e6d801768b..1a7e8d811a08 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -34,6 +34,13 @@
 #define SG_MEMPOOL_NR           ARRAY_SIZE(scsi_sg_pools)
 #define SG_MEMPOOL_SIZE         2
 
+/*
+ * The maximum number of SG segments that we will put inside a scatterlist
+ * (unless chaining is used). Should ideally fit inside a single page, to
+ * avoid a higher order allocation.
+ */
+#define SCSI_MAX_SG_SEGMENTS    128
+
 struct scsi_host_sg_pool {
         size_t          size;
         char            *name;
@@ -45,9 +52,15 @@ struct scsi_host_sg_pool {
 static struct scsi_host_sg_pool scsi_sg_pools[] = {
         SP(8),
         SP(16),
+#if (SCSI_MAX_SG_SEGMENTS > 16)
         SP(32),
+#if (SCSI_MAX_SG_SEGMENTS > 32)
         SP(64),
+#if (SCSI_MAX_SG_SEGMENTS > 64)
         SP(128),
+#endif
+#endif
+#endif
 };
 #undef SP
 
@@ -685,13 +698,6 @@ static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
 }
 
 /*
- * The maximum number of SG segments that we will put inside a scatterlist
- * (unless chaining is used). Should ideally fit inside a single page, to
- * avoid a higher order allocation.
- */
-#define SCSI_MAX_SG_SEGMENTS    128
-
-/*
  * Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit
  * is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
  */
@@ -708,15 +714,21 @@ static inline unsigned int scsi_sgtable_index(unsigned short nents)
         case 9 ... 16:
                 index = 1;
                 break;
+#if (SCSI_MAX_SG_SEGMENTS > 16)
         case 17 ... 32:
                 index = 2;
                 break;
+#if (SCSI_MAX_SG_SEGMENTS > 32)
         case 33 ... 64:
                 index = 3;
                 break;
-        case 65 ... SCSI_MAX_SG_SEGMENTS:
+#if (SCSI_MAX_SG_SEGMENTS > 64)
+        case 65 ... 128:
                 index = 4;
                 break;
+#endif
+#endif
+#endif
         default:
                 printk(KERN_ERR "scsi: bad segment count=%d\n", nents);
                 BUG();