LU-15274 llite: whole file read fixes

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

diff --git a/lustre/tests/sanity.sh b/lustre/tests/sanity.sh
index a3f223b..91a5010 100755 (executable)
--- a/lustre/tests/sanity.sh
+++ b/lustre/tests/sanity.sh
@@ -23830,6 +23830,61 @@ test_248b() {
 }
 run_test 248b "test short_io read and write for both small and large sizes"
 
+test_248c() {
+       $LCTL set_param llite.*.read_ahead_stats=c
+       # This test compares whole file readahead to non-whole file readahead
+       # The performance should be consistently slightly faster for whole file,
+       # and the bug caused whole file readahead to be 80-100x slower, but to
+       # account for possible test system lag, we require whole file to be
+       # <= 1.5xnon-whole file, and require 3 failures in a row to fail the
+       # test
+       local time1
+       local time2
+       local whole_mb=$($LCTL get_param -n llite.*.max_read_ahead_whole_mb)
+       stack_trap "$LCTL set_param llite.*.max_read_ahead_whole_mb=$whole_mb" EXIT
+       counter=0
+
+       while [ $counter -lt 3 ]; do
+               # Increment the counter
+               ((counter++))
+
+               $LCTL set_param llite.*.max_read_ahead_whole_mb=64
+               rm -f $DIR/$tfile
+               touch $DIR/$tfile || error "(0) failed to create file"
+               # 64 MiB
+               $TRUNCATE $DIR/$tfile 67108864 || error "(1) failed to truncate file"
+               time1=$(dd if=$DIR/$tfile bs=4K of=/dev/null 2>&1 | awk '/bytes/ {print $8}')
+               echo "whole file readahead of 64 MiB took $time1 seconds"
+               $LCTL get_param llite.*.read_ahead_stats
+
+               $LCTL set_param llite.*.read_ahead_stats=c
+               $LCTL set_param llite.*.max_read_ahead_whole_mb=8
+               rm -f $DIR/$tfile
+               touch $DIR/$tfile || error "(2) failed to create file"
+               # 64 MiB
+               $TRUNCATE $DIR/$tfile 67108864 || error "(3) failed to create file"
+               time2=$(dd if=$DIR/$tfile bs=4K of=/dev/null 2>&1 | awk '/bytes/ {print $8}')
+               echo "non-whole file readahead of 64 MiB took $time2 seconds"
+               $LCTL get_param llite.*.read_ahead_stats
+
+               # Check if time1 is not more than 1.5 times2
+               timecheck=$(echo "$time1 <= (1.5 * $time2)" | bc -l)
+
+               if [[ $timecheck -eq 1 ]]; then
+                       echo "Test passed on attempt $counter"
+                       # Exit the loop
+                       counter=4
+               else
+                       echo "Attempt $counter failed: whole file readahead took: $time1, greater than non: $time2"
+               fi
+       done
+       if [ $counter -eq 3 ]; then
+               error "whole file readahead check failed 3 times in a row, probably not just VM lag"
+       fi
+
+}
+run_test 248c "verify whole file read behavior"
+
 test_249() { # LU-7890
        [ $MDS1_VERSION -lt $(version_code 2.8.53) ] &&
                skip "Need at least version 2.8.54"