bzr commit into mysql-trunk-innodb branch (inaam.rana:3238) Bug#56646

[Inaam Rana]

#At file:///home/inaam/w/mysql-trunk-innodb/ based on revid:vasil.dimov@stripped

 3238 Inaam Rana	2010-09-09
      bug#56646 Add option to disable readahead in innodb
      
      With this fix the value '0' will mean that no readahead will take place.

    modified:
      storage/innobase/buf/buf0rea.c
=== modified file 'storage/innobase/buf/buf0rea.c'
--- a/storage/innobase/buf/buf0rea.c	revid:vasil.dimov@stripped
+++ b/storage/innobase/buf/buf0rea.c	revid:inaam.rana@stripped
@@ -256,6 +256,11 @@ buf_read_ahead_linear(
 		= BUF_READ_AHEAD_LINEAR_AREA(buf_pool);
 	ulint		threshold;
 
+	/* check if readahead is disabled */
+	if (!srv_read_ahead_threshold) {
+		return(0);
+	}
+
 	if (UNIV_UNLIKELY(srv_startup_is_before_trx_rollback_phase)) {
 		/* No read-ahead to avoid thread deadlocks */
 		return(0);


Attachment: [text/bzr-bundle] bzr/[e-mail]