code.ossystems Code Review - openembedded-core.git/blob

   1 From 8fe742807e65af29dac3fea568ff93cbc5dd9a56 Mon Sep 17 00:00:00 2001
   2 From: Michael Jeanson <mjeanson@efficios.com>
   3 Date: Mon, 24 Aug 2020 15:26:04 -0400
   4 Subject: [PATCH 04/10] fix: ext4: limit the length of per-inode prealloc list
   5  (v5.9)
   6 MIME-Version: 1.0
   7 Content-Type: text/plain; charset=UTF-8
   8 Content-Transfer-Encoding: 8bit
   9
  10 See upstream commit:
  11
  12   commit 27bc446e2def38db3244a6eb4bb1d6312936610a
  13   Author: brookxu <brookxu.cn@gmail.com>
  14   Date:   Mon Aug 17 15:36:15 2020 +0800
  15
  16     ext4: limit the length of per-inode prealloc list
  17
  18     In the scenario of writing sparse files, the per-inode prealloc list may
  19     be very long, resulting in high overhead for ext4_mb_use_preallocated().
  20     To circumvent this problem, we limit the maximum length of per-inode
  21     prealloc list to 512 and allow users to modify it.
  22
  23     After patching, we observed that the sys ratio of cpu has dropped, and
  24     the system throughput has increased significantly. We created a process
  25     to write the sparse file, and the running time of the process on the
  26     fixed kernel was significantly reduced, as follows:
  27
  28     Running time on unfixed kernel：
  29     [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
  30     real    0m2.051s
  31     user    0m0.008s
  32     sys     0m2.026s
  33
  34     Running time on fixed kernel：
  35     [root@TENCENT64 ~]# time taskset 0x01 ./sparse /data1/sparce.dat
  36     real    0m0.471s
  37     user    0m0.004s
  38     sys     0m0.395s
  39
  40 Upstream-Status: Backport
  41
  42 Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
  43 Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  44 Change-Id: I5169cb24853d4da32e2862a6626f1f058689b053
  45 ---
  46  instrumentation/events/lttng-module/ext4.h | 15 +++++++++++++++
  47  1 file changed, 15 insertions(+)
  48
  49 diff --git a/instrumentation/events/lttng-module/ext4.h b/instrumentation/events/lttng-module/ext4.h
  50 index 5f7ab28..72ad4c9 100644
  51 --- a/instrumentation/events/lttng-module/ext4.h
  52 +++ b/instrumentation/events/lttng-module/ext4.h
  53 @@ -460,6 +460,20 @@ LTTNG_TRACEPOINT_EVENT(ext4_mb_release_group_pa,
  54  )
  55  #endif
  56
  57 +#if (LINUX_VERSION_CODE >= KERNEL_VERSION(5,9,0))
  58 +LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
  59 +       TP_PROTO(struct inode *inode, unsigned int len, unsigned int needed),
  60 +
  61 +       TP_ARGS(inode, len, needed),
  62 +
  63 +       TP_FIELDS(
  64 +               ctf_integer(dev_t, dev, inode->i_sb->s_dev)
  65 +               ctf_integer(ino_t, ino, inode->i_ino)
  66 +               ctf_integer(unsigned int, len, len)
  67 +               ctf_integer(unsigned int, needed, needed)
  68 +       )
  69 +)
  70 +#else
  71  LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
  72         TP_PROTO(struct inode *inode),
  73
  74 @@ -470,6 +484,7 @@ LTTNG_TRACEPOINT_EVENT(ext4_discard_preallocations,
  75                 ctf_integer(ino_t, ino, inode->i_ino)
  76         )
  77  )
  78 +#endif
  79
  80  LTTNG_TRACEPOINT_EVENT(ext4_mb_discard_preallocations,
  81         TP_PROTO(struct super_block *sb, int needed),
  82 --
  83 2.19.1
  84