reduce the number of processes forked

One of the big cpu time consumers when running xfsqa on UML
is forking of new processes. when looping lots of times,
using 'expr' to calculate the loop counter increment means
we fork at least once every loop. using shell builtins means
that we don't fork and many tests run substantially faster.

Some tests are even runnable with this modification. e.g. 110
went from taking 4500s to run down to 9s with the loop iterators
changed to avoid forking.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

007

@@ -50,7 +50,7 @@ num_filenames=100
 i=1
 while [ $i -le $num_filenames ]; do
   echo "nametest.$i" >>$sourcefile
-  i=`expr $i + 1`
+  let i=$i+1
 done
 
 mkdir $testdir/$seq

028

@@ -44,7 +44,7 @@ while [ $i -lt 5 ]; do
     fi
     rm $dump_file
     sleep 2
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 echo "middate = $middate" >>$seq.full

031

@@ -71,7 +71,7 @@ EOF
 
 	while [ $count -lt $total ]
 	do
-		count=`expr $count + 1`
+		let count=$count+1
 		cat >>$tmp.proto <<EOF
 ${count}_of_${total}_xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx ---755 3 1 /bin/true
 EOF

047

@@ -44,7 +44,7 @@ while [ $i -lt 5 ]; do
     fi
     rm $dump_file
     sleep 2
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 echo "middate = $middate" >>$seq.full

053

@@ -54,7 +54,7 @@ for acl in $acls
 do
   _do "touch $test.$i"
   _do "chacl $acl $test.$i"
-  i=`expr $i + 1`
+  let i=$i+1
 done
 
 list_acls()
@@ -63,7 +63,7 @@ list_acls()
   for acl in $acls
   do
     chacl -l $test.$i | _acl_filter_id | sed -e "s!$SCRATCH_MNT!\$SCRATCH_MNT!"
-    i=`expr $i + 1`
+    let i=$i+1
   done
 }
 

064

@@ -58,7 +58,7 @@ while [ $i -le 9 ]; do
     date >>$seq.full
     find $SCRATCH_MNT -exec $here/src/lstat64 {} \; | sed 's/(00.*)//' >$tmp.dates.$i
     if [ $i -gt 0 ]; then
-       level_1=`expr $i - 1`
+       let level_1=$i-1
        diff -c $tmp.dates.$level_1 $tmp.dates.$i >>$seq.full
     else
        cat $tmp.dates.$i >>$seq.full
@@ -66,7 +66,7 @@ while [ $i -le 9 ]; do
 
     dump_file=$tmp.df.level$i
     _do_dump_file -l $i
-    i=`expr $i + 1`	
+    let i=$i+1
 done
 
 echo "Listing of what files we start with:"
@@ -79,7 +79,7 @@ while [ $i -le 9 ]; do
     echo "restoring from df.level$i"
     dump_file=$tmp.df.level$i
     _do_restore_toc
-    i=`expr $i + 1`	
+    let i=$i+1
 done
 
 echo "Do the cumulative restores"
@@ -91,7 +91,7 @@ while [ $i -le 9 ]; do
     _do_restore_file_cum -l $i
     echo "ls -l restore_dir"
     ls -lR $restore_dir | _ls_size_filter | _check_quota_file
-    i=`expr $i + 1`	
+    let i=$i+1
 done
 
 # success, all done

065

@@ -146,7 +146,7 @@ while [ $i -le $num_dumps ]; do
 
     dump_file=$tmp.df.level$i
     _do_dump_file -l $i
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 echo "Look at what files are contained in the inc. dump"
@@ -156,7 +156,7 @@ while [ $i -le $num_dumps ]; do
     echo "restoring from df.level$i"
     dump_file=$tmp.df.level$i
     _do_restore_toc
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 echo "Do the cumulative restores"
@@ -168,7 +168,7 @@ while [ $i -le $num_dumps ]; do
     _do_restore_file_cum -l $i
     echo "list restore_dir"
     _list_dir $restore_dir | _check_quota_file | tee $tmp.restorals.$i
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 echo ""
@@ -178,7 +178,7 @@ while [ $i -le $num_dumps ]; do
     echo "Comparing ls of FS with restored FS at level $i"
     diff -s $tmp.ls.$i $tmp.restorals.$i | sed "s#$tmp#TMP#g"
     echo ""
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 

068

@@ -75,7 +75,7 @@ touch $tmp.running
 } &
 
 i=0
-ITERATIONS=`expr $ITERATIONS - 1`
+let ITERATIONS=$ITERATIONS-1
 
 echo | tee -a $seq.full
 while [ $i -le $ITERATIONS ]
@@ -94,7 +94,7 @@ do
 	sleep 2
 
 	echo  | tee -a $seq.full
-	i=`expr $i + 1`
+	let i=$i+1
 done
 
 # stop fsstress iterations

071

@@ -137,7 +137,7 @@ do
     echo === Iterating, `expr $upperbound - $count` remains
     echo
     echo
-    count=`expr $count + 1`
+    let count=$count+1
 done
 
 # success, all done

089

@@ -30,7 +30,7 @@ addentries()
 
 	while [ $count -gt 0 ]; do
 		touch `printf $pattern $count`
-		count=`expr $count - 1`
+		let count=$count-1
 	done
 }
 

109

@@ -38,7 +38,7 @@ populate()
 	while [ $i -le $files -a "X$faststart" = "X" ]; do
 		file=$SCRATCH_MNT/f$i
 		xfs_io -f -d -c 'pwrite -b 64k 0 64k' $file >/dev/null
-		i=`expr $i + 1`
+		let i=$i+1
 	done
 
 	# remove every second file, freeing up lots of space
@@ -46,7 +46,7 @@ populate()
 	i=1
 	while [ $i -le $files -a "X$faststart" = "X" ]; do
 		rm $SCRATCH_MNT/f$i
-		i=`expr $i + 2`
+		let i=$i+2
 	done
 
 	echo "flushing changes via umount/mount."
@@ -67,10 +67,10 @@ allocate()
 				xfs_io -f -c 'pwrite -b 64k 0 16m' $file \
 					>/dev/null 2>&1
 				rm $file
-				j=`expr $j + 1`
+				let j=$j+1
 			done
 		} &
-		i=`expr $i + 1`
+		let i=$i+1
 	done
 
 	wait

110

@@ -52,8 +52,8 @@ E=10030600
 while [ $I -le $E ]
 do
     echo > $SCRATCH_MNT/test/${STR1}${STR2}${STR3}${I}
-    I=`expr $I + 1`
-    [ `expr $I % 1000` -eq 0 ] && echo "Created $I/$E"
+    let I=$I+1
+    [ $[$I % 1000] -eq 0 ] && echo "Created $I/$E"
 done
 
 sync
@@ -63,7 +63,7 @@ E=10030599
 while [ $I -le $E ]
 do
     rm $SCRATCH_MNT/test/${STR1}${STR2}${STR3}${I} &
-    I=`expr $I + 1`
+    let I=$I+1
 done
 
 _check_scratch_fs

111

@@ -39,7 +39,7 @@ I=0
 while [ $I -lt 1000 ]
 do
     cp src/itrash.c $SCRATCH_MNT/${I}
-    I=`expr $I + 1`
+    let I=$I+1
 done
 umount $SCRATCH_DEV
 

113

@@ -41,7 +41,7 @@ _do_test()
     [ $__proc -gt 1 ] && _param="-t $__proc $_param"
     while [ $__proc -gt 1 ]; do
         _files="$_files $testdir/aiostress.$$.$_n.$__proc"
-	__proc=`expr $__proc - 1`
+	let __proc=$__proc-1
     done
     rm -f $_files
  

114

@@ -135,8 +135,8 @@ _test_hardlink()
 	paths="$d/l1 $d/l2 $d/l3 $d2/l4 $d2/l5 $d2/l6"
 	i=0
 	for x in $paths; do
-		i=`expr $i + 1`
-		j=`expr $i % 2`
+		let i=$i+1
+		let j=$i%2
 		if [ $j -eq 0 ]; then
 			echo "rm'ing $x"
 			rm $x

117

@@ -71,7 +71,7 @@ while [ $i -lt $ITERATIONS ]; do
         -s $seed \
 	-S -p 1 -n 1000 >>$seq.full 2>&1
 
-    i=`expr $i + 1`
+    let i=$i+1
 done
 
 cd /

119

@@ -54,7 +54,7 @@ while [ $i -lt $max ]; do
 	xfs_freeze -f $SCRATCH_MNT
 	xfs_freeze -u $SCRATCH_MNT
 	echo -n .
-	i=`expr $i + 1`
+	let i=$i+1
 done
 echo "done"
 

136

@@ -61,7 +61,7 @@ add_eas()
     i=$start
     while [ $i -le $end ]; do 
 	attr -s name.$i -V value $file >/dev/null
-	i=`expr $i + 1`
+	let i=$i+1
     done
 }
 
@@ -73,7 +73,7 @@ rm_eas()
     i=$start
     while [ $i -le $end ]; do 
 	attr -r name.$i $file >/dev/null
-	i=`expr $i + 1`
+	let i=$i+1
     done
 }
 
@@ -171,7 +171,7 @@ _test_add_extents()
 	while [ $j -le 30 ]; do
 	    do_extents $j
 	    _print_inode
-	    j=`expr $j + 2`
+	    let j=$j+2
 	done
 
 	#scale down
@@ -179,7 +179,7 @@ _test_add_extents()
 	while [ $j -ge 1 ]; do
 	    do_extents $j
 	    _print_inode
-	    j=`expr $j - 2`
+	    let j=$j-2
 	done
 
 	#build up
@@ -187,7 +187,7 @@ _test_add_extents()
 	while [ $j -le 30 ]; do
 	    do_extents $j
 	    _print_inode
-	    j=`expr $j + 2`
+	    let j=$j+2
 	done
 }
 
@@ -211,7 +211,7 @@ _test_extents_eas()
 	    _print_inode
 	    _print_inode_u > $tmp.u1
 	    for j in `seq 1 $EAs_inc $EAs_max`; do
-		k=`expr $j + $EAs_inc - 1`
+		let k=$k+$EAs_inc-1
 		add_eas $j $k
 	    done
 	    # should have same extents
@@ -256,7 +256,7 @@ _test_eas_extents()
 	EAs_inc=5
 	for j in `seq 1 $EAs_inc $EAs_max`; do
 
-	    k=`expr $j + $EAs_inc - 1`
+	    let k=$k+$EAs_inc-1
 	    add_eas $j $k
 	    echo "--- EAs: $j ---"
 

137

@@ -47,7 +47,7 @@ do
 		echo error creating/writing file $file
 		exit
 	fi
-	i=`expr $i + 1`
+	let i=$i+1
 done
 
 # give the system a chance to write something out
@@ -90,7 +90,7 @@ do
 			rm -f $file
 		fi
 	fi
-	i=`expr $i + 1`
+	let i=$i+1
 done
 
 status=0

138

@@ -53,7 +53,7 @@ do
 		echo error truncating file $file
 		exit
 	fi
-	i=`expr $i + 1`
+	let i=$i+1
 done
 
 # give the system a chance to write something out
@@ -96,7 +96,7 @@ do
 			rm -f $file
 		fi
 	fi
-	i=`expr $i + 1`
+	let i=$i+1
 done
 
 status=0