From 3ff2f67a7c24183fcbcfe1332e5223ac6f96438c Mon Sep 17 00:00:00 2001 From: Evgeny Yakovlev Date: Mon, 18 Jul 2016 22:39:52 +0300 Subject: block: ignore flush requests when storage is clean Some guests (win2008 server for example) do a lot of unnecessary flushing when underlying media has not changed. This adds additional overhead on host when calling fsync/fdatasync. This change introduces a write generation scheme in BlockDriverState. Current write generation is checked against last flushed generation to avoid unnessesary flushes. The problem with excessive flushing was found by a performance test which does parallel directory tree creation (from 2 processes). Results improved from 0.424 loops/sec to 0.432 loops/sec. Each loop creates 10^3 directories with 10 files in each. This affected some blkdebug testcases that were expecting error logs from failure-injected flushes which are now skipped entirely (tests 026 071 089). This also affects the performance of block jobs and thus BLOCK_JOB_READY events for driver-mirror and active block-commit commands now arrives faster, before QMP send successfully returns to caller (tests 141 144). Signed-off-by: Evgeny Yakovlev Signed-off-by: Denis V. Lunev Reviewed-by: Paolo Bonzini Message-id: 1468870792-7411-5-git-send-email-den@openvz.org CC: Kevin Wolf CC: Max Reitz CC: Stefan Hajnoczi CC: Fam Zheng CC: John Snow Signed-off-by: John Snow --- tests/qemu-iotests/026.out.nocache | 50 -------------------------------------- 1 file changed, 50 deletions(-) (limited to 'tests/qemu-iotests/026.out.nocache') diff --git a/tests/qemu-iotests/026.out.nocache b/tests/qemu-iotests/026.out.nocache index 9c2c8a9486..672d77c6ec 100644 --- a/tests/qemu-iotests/026.out.nocache +++ b/tests/qemu-iotests/026.out.nocache @@ -14,7 +14,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_update; errno: 5; imm: off; once: off; write -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error @@ -23,7 +22,6 @@ This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_update; errno: 5; imm: off; once: off; write -b -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error @@ -42,7 +40,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_update; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -51,7 +48,6 @@ This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_update; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -78,11 +74,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l2_load; errno: 5; imm: off; once: off; write wrote 131072/131072 bytes at offset 0 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error write failed: Input/output error -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error read failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -90,11 +82,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l2_load; errno: 5; imm: off; once: off; write -b wrote 131072/131072 bytes at offset 0 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error write failed: Input/output error -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error read failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -118,11 +106,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l2_load; errno: 28; imm: off; once: off; write wrote 131072/131072 bytes at offset 0 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device write failed: No space left on device -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device read failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -130,11 +114,7 @@ Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l2_load; errno: 28; imm: off; once: off; write -b wrote 131072/131072 bytes at offset 0 128 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device write failed: No space left on device -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device read failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -314,14 +294,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_load; errno: 5; imm: off; once: off; write -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_load; errno: 5; imm: off; once: off; write -b -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. @@ -338,14 +316,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_load; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_load; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. @@ -362,14 +338,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_update_part; errno: 5; imm: off; once: off; write -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_update_part; errno: 5; imm: off; once: off; write -b -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. @@ -386,14 +360,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_update_part; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_update_part; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. @@ -410,14 +382,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc; errno: 5; imm: off; once: off; write -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc; errno: 5; imm: off; once: off; write -b -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. @@ -434,14 +404,12 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. @@ -458,15 +426,11 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: cluster_alloc; errno: 5; imm: off; once: off; write -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: cluster_alloc; errno: 5; imm: off; once: off; write -b -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -482,15 +446,11 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: cluster_alloc; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: cluster_alloc; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. @@ -561,7 +521,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -570,7 +529,6 @@ This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc_write_blocks; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -589,7 +547,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -598,7 +555,6 @@ This means waste of disk space, but no harm to data. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: refblock_alloc_write_table; errno: 28; imm: off; once: off; write -b -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device @@ -643,8 +599,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_grow_alloc_table; errno: 5; imm: off; once: off -Failed to flush the L2 table cache: Input/output error -Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -655,8 +609,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_grow_alloc_table; errno: 28; imm: off; once: off -Failed to flush the L2 table cache: No space left on device -Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 @@ -667,7 +619,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_grow_write_table; errno: 5; imm: off; once: off -Failed to flush the L2 table cache: Input/output error Failed to flush the refcount block cache: Input/output error write failed: Input/output error No errors were found on the image. @@ -679,7 +630,6 @@ No errors were found on the image. Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1073741824 Event: l1_grow_write_table; errno: 28; imm: off; once: off -Failed to flush the L2 table cache: No space left on device Failed to flush the refcount block cache: No space left on device write failed: No space left on device No errors were found on the image. -- cgit v1.2.3