[XFS] choose single default logbuf count & size

Remove sizing of logbuf size & count based on physical memory; this was
never a very good gauge as it's looking at global memory, but deciding on
sizing per-filesystem; no account is made of the total number of
filesystems, for example.

For now just take the largest "default" case, as was set for machines with
>400MB - 8 x 32k buffers. This can always be tuned higher or lower with
mount options if necessary. Removes one more user of xfs_physmem.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29323a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

2 files changed, 7 insertions, 27 deletions

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index db09e1ea5cf3..4f4d20b2721c 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1025,10 +1025,7 @@ xlog_bdstrat_cb(struct xfs_buf *bp)
 /*
  * Return size of each in-core log record buffer.
  *
- * Low memory machines only get 2 16KB buffers.  We don't want to waste
- * memory here.  However, all other machines get at least 2 32KB buffers.
- * The number is hard coded because we don't care about the minimum
- * memory size, just 32MB systems.
+ * All machines get 8 x 32KB buffers by default, unless tuned otherwise.
  *
  * If the filesystem blocksize is too large, we may need to choose a
  * larger size since the directory code currently logs entire blocks.
@@ -1041,17 +1038,10 @@ xlog_get_iclog_buffer_size(xfs_mount_t	*mp,
         int size;
         int xhdrs;
 
-        if (mp->m_logbufs <= 0) {
-                if (xfs_physmem <= btoc(128*1024*1024)) {
-                        log->l_iclog_bufs = XLOG_MIN_ICLOGS;
-                } else if (xfs_physmem <= btoc(400*1024*1024)) {
-                        log->l_iclog_bufs = XLOG_MED_ICLOGS;
-                } else {        /* 256K with 32K bufs */
-                        log->l_iclog_bufs = XLOG_MAX_ICLOGS;
-                }
-        } else {
+        if (mp->m_logbufs <= 0)
+                log->l_iclog_bufs = XLOG_MAX_ICLOGS;
+        else
                 log->l_iclog_bufs = mp->m_logbufs;
-        }
 
         /*
          * Buffer size passed in from mount system call.
@@ -1082,18 +1072,9 @@ xlog_get_iclog_buffer_size(xfs_mount_t	*mp,
                 goto done;
         }
 
-        /*
-         * Special case machines that have less than 32MB of memory.
-         * All machines with more memory use 32KB buffers.
-         */
-        if (xfs_physmem <= btoc(32*1024*1024)) {
-                /* Don't change; min configuration */
-                log->l_iclog_size = XLOG_RECORD_BSIZE;          /* 16k */
-                log->l_iclog_size_log = XLOG_RECORD_BSHIFT;
-        } else {
-                log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;      /* 32k */
-                log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
-        }
+        /* All machines use 32KB buffers by default. */
+        log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
+        log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
 
         /* the default log size is 16k or 32k which is one header sector */
         log->l_iclog_hsize = BBSIZE;
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 9bd3cdf11a87..e973972d4633 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -30,7 +30,6 @@ struct xfs_mount;
  */
 
 #define XLOG_MIN_ICLOGS         2
-#define XLOG_MED_ICLOGS         4
 #define XLOG_MAX_ICLOGS         8
 #define XLOG_HEADER_MAGIC_NUM   0xFEEDbabe      /* Invalid cycle number */
 #define XLOG_VERSION_1          1