LU-13138 tests: measure 'dd' time more accurately

[fs/lustre-release.git] / lustre / tests / sanity.sh

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index 62a7f89..860e95f 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -9161,17 +9161,21 @@ test_101d() {
        stack_trap "$LCTL set_param -n llite.*.max_read_ahead_mb $old_RA" EXIT
        $LCTL get_param -n llite.*.max_read_ahead_mb
 
-       echo Reading the test file $file with read-ahead disabled
+       echo "Reading the test file $file with read-ahead disabled"
        local sz_KB=$((sz_MB * 1024 / 4))
-       local raOFF=$(do_and_time "dd if=$file of=/dev/null bs=4k count=$sz_KB")
+       # 10485760 bytes transferred in 0.000938 secs (11179579337 bytes/sec)
+       # 104857600 bytes (105 MB) copied, 0.00876352 s, 12.0 GB/s
+       local raOFF=$(LANG=C dd if=$file of=/dev/null bs=4k count=$sz_KB |&
+                     sed -e '/records/d' -e 's/.* \([0-9]*\.[0-9]*\) *s.*/\1/')
 
-       echo Cancel LRU locks on lustre client to flush the client cache
+       echo "Cancel LRU locks on lustre client to flush the client cache"
        cancel_lru_locks osc
        echo Enable read-ahead with ${ra_MB}MB
        $LCTL set_param -n llite.*.max_read_ahead_mb=$ra_MB
 
-       echo Reading the test file $file with read-ahead enabled
-       local raON=$(do_and_time "dd if=$file of=/dev/null bs=4k count=$sz_KB")
+       echo "Reading the test file $file with read-ahead enabled"
+       local raON=$(LANG=C dd if=$file of=/dev/null bs=4k count=$sz_KB |&
+                    sed -e '/records/d' -e 's/.* \([0-9]*\.[0-9]*\) *s.*/\1/')
 
        echo "read-ahead disabled time read $raOFF"
        echo "read-ahead enabled time read $raON"
@@ -9179,7 +9183,8 @@ test_101d() {
        rm -f $file
        wait_delete_completed
 
-       [ $raOFF -le 1 ] || [ $raON -lt $raOFF ] ||
+       # use awk for this check instead of bash because it handles decimals
+       awk "{ exit !($raOFF < 1.0 || $raOFF > $raON) }" <<<"ignore_me" ||
                error "readahead ${raON}s > no-readahead ${raOFF}s ${sz_MB}M"
 }
 run_test 101d "file read with and without read-ahead enabled"