From: Ben Gras <ben@minix3.org>
Date: Wed, 21 Sep 2011 18:48:48 +0000 (+0000)
Subject: mfs: ditch global readahead
X-Git-Tag: v3.2.0~273
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/mult.png?a=commitdiff_plain;h=c83a90e2f189b4a28517d51d5e4cbe8024383bc2;p=minix.git

mfs: ditch global readahead
---

diff --git a/servers/mfs/main.c b/servers/mfs/main.c
index d0b3408f7..96b9c5afe 100644
--- a/servers/mfs/main.c
+++ b/servers/mfs/main.c
@@ -77,10 +77,6 @@ PUBLIC int main(int argc, char *argv[])
 		fs_m_out.m_type = TRNS_ADD_ID(fs_m_out.m_type, transid);
 	}
 	reply(src, &fs_m_out);
-
-	if (error == OK) 
-		read_ahead(); /* do block read ahead */
-      
   }
 
   return(OK);
diff --git a/servers/mfs/read.c b/servers/mfs/read.c
index abf0af653..27cdd9e91 100644
--- a/servers/mfs/read.c
+++ b/servers/mfs/read.c
@@ -12,7 +12,7 @@
 
 
 FORWARD _PROTOTYPE( struct buf *rahead, (struct inode *rip, block_t baseblock,
-			u64_t position, unsigned bytes_ahead)		);
+                       u64_t position, unsigned bytes_ahead)           );
 FORWARD _PROTOTYPE( int rw_chunk, (struct inode *rip, u64_t position,
 	unsigned off, size_t chunk, unsigned left, int rw_flag,
 	cp_grant_id_t gid, unsigned buf_off, unsigned int block_size,
@@ -20,9 +20,6 @@ FORWARD _PROTOTYPE( int rw_chunk, (struct inode *rip, u64_t position,
 
 PRIVATE char getdents_buf[GETDENTS_BUFSIZ];
 
-PRIVATE off_t rdahedpos;         /* position to read ahead */
-PRIVATE struct inode *rdahed_inode;      /* pointer to inode to read ahead */
-
 /*===========================================================================*
  *				fs_readwrite				     *
  *===========================================================================*/
@@ -112,14 +109,6 @@ PUBLIC int fs_readwrite(void)
 	  }
   } 
 
-  /* Check to see if read-ahead is called for, and if so, set it up. */
-  if(rw_flag == READING && rip->i_seek == NO_SEEK &&
-     (unsigned int) position % block_size == 0 &&
-     (regular || mode_word == I_DIRECTORY)) {
-	  rdahed_inode = rip;
-	  rdahedpos = position;
-  } 
-
   rip->i_seek = NO_SEEK;
 
   if (rdwt_err != OK) r = rdwt_err;	/* check for disk error */
@@ -392,33 +381,6 @@ int index;			/* index into *bp */
   return(zone);
 }
 
-
-/*===========================================================================*
- *				read_ahead				     *
- *===========================================================================*/
-PUBLIC void read_ahead()
-{
-/* Read a block into the cache before it is needed. */
-  unsigned int block_size;
-  register struct inode *rip;
-  struct buf *bp;
-  block_t b;
-
-  if(!rdahed_inode)
-	return;
-
-  rip = rdahed_inode;		/* pointer to inode to read ahead from */
-  block_size = get_block_size(rip->i_dev);
-  rdahed_inode = NULL;	/* turn off read ahead */
-  if ( (b = read_map(rip, rdahedpos)) == NO_BLOCK) return;	/* at EOF */
-
-  assert(rdahedpos >= 0); /* So we can safely cast it to unsigned below */
-
-  bp = rahead(rip, b, cvul64( (unsigned long) rdahedpos), block_size);
-  put_block(bp, PARTIAL_DATA_BLOCK);
-}
-
-
 /*===========================================================================*
  *				rahead					     *
  *===========================================================================*/