<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:宋体;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:"\@宋体";
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:宋体;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin:0cm;
margin-bottom:.0001pt;
text-indent:21.0pt;
font-size:12.0pt;
font-family:宋体;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:12.0pt;
font-family:宋体;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:等线;
color:#1F497D;}
span.pl-c1
{mso-style-name:pl-c1;}
span.pl-s
{mso-style-name:pl-s;}
span.pl-pds
{mso-style-name:pl-pds;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:等线;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:212272806;
mso-list-type:hybrid;
mso-list-template-ids:-778001670 2079878332 67698691 67698693 67698689 67698691 67698693 67698689 67698691 67698693;}
@list l0:level1
{mso-level-start-at:0;
mso-level-number-format:bullet;
mso-level-text:-;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:18.0pt;
text-indent:-18.0pt;
font-family:Consolas;
mso-fareast-font-family:宋体;
mso-bidi-font-family:宋体;}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:42.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:63.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:84.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:105.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:126.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:147.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:168.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:189.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="ZH-CN" link="blue" vlink="purple">
<div class="WordSection1">
<div>
<div>
<div>
<div>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Hi, Li<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">></span><span style="color:#1F497D">发件人<span lang="EN-US">: Li Wang <liwang@redhat.com>
<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">></span><span style="color:#1F497D">发送时间<span lang="EN-US">: 2020</span>年<span lang="EN-US">10</span>月<span lang="EN-US">14</span>日<span lang="EN-US"> 14:28<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">></span><span style="color:#1F497D">收件人<span lang="EN-US">: Xu, Yang <xuyang2018.jy@cn.fujitsu.com>; Chen, Hanxiao <chenhx.fnst@cn.fujitsu.com><o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">></span><span style="color:#1F497D">抄送<span lang="EN-US">: LTP List <ltp@lists.linux.it><o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">></span><span style="color:#1F497D">主题<span lang="EN-US">: Re:
</span>答复<span lang="EN-US">: [LTP] [PATCH] memcg_use_hierarchy_test.sh: skip setting use_hierarchy if not available<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>On Tue, Oct 13, 2020 at 11:19 AM Yang Xu <xuyang2018.jy@cn.fujitsu.com> wrote:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>Hi Hanxiao<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> Hi, Yang<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>>> -----</span><span style="color:#1F497D">閭<span lang="EN-US"></span>欢鍘熶欢<span lang="EN-US">-----<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>>> </span><span style="color:#1F497D">涓婚<span lang="EN-US">: Re: [LTP] [PATCH] memcg_use_hierarchy_test.sh: skip setting<o:p></o:p></span></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>>> use_hierarchy if not available<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">[snip]<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> The behavior above looks conflicting with https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>Yes. Centos7 behavior is different from the documentation.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>>> So why not directly use /dev/memcg/memory.use_hierarchy value to judge in<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>>> testcase after setting 0.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> In setup_test from memcg_lib.sh, we actually did:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> mount -t cgroup -omemory memcg /dev/memcg<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> Then kernel will find a suitable cgroup root for us in cgroup1_mount.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> In this case, /sys/fs/cgroup/memory/ would be the good choice.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>> So it's equivalent to read memory.use_hierarchy from either side.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>I understand. Only a minor suggestion, please use tabs instead of spaces<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>at the beginning of the line.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>This patch looks good to me,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>Acked-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>@Li, I think this patch is ok, Do you have some comment about it?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>I'm ok to go with memory.use_hierarchy checking in the preconditioning phase.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>But how can you assert the default memory cgroup is mount at path: "/sys/fs/cgroup/memory", is there any possibility the default path mount at other places(for different distribution)?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><a href="https://github.com/torvalds/linux/blob/b5fc7a89e58bcc059a3d5e4db79c481fb437de59/kernel/cgroup/cgroup.c#L5768"><span style="color:#1F497D;text-decoration:none">https://github.com/torvalds/linux/blob/b5fc7a89e58bcc059a3d5e4db79c481fb437de59/kernel/cgroup/cgroup.c#L5768</span></a><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">WARN_ON(sysfs_create_mount_point(fs_kobj, "cgroup"));<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">So the default mount place should be /sys/fs/cgroup if distributions<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">did not modify these lines.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">As the discussion above,
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">mount -t cgroup -omemory memcg /dev/memcg<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">kernel will find a suitable cgroup root for us.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">How about reading /dev/memcg/memory.use_hierarchy as Yang recommended instead?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Regards,<o:p></o:p></span></p>
<p class="MsoListParagraph" style="margin-left:18.0pt;text-indent:-18.0pt;mso-list:l0 level1 lfo1">
<![if !supportLists]><span lang="EN-US" style="font-family:Consolas;color:#1F497D"><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span></span><![endif]><span lang="EN-US" style="color:#1F497D">Hanxiao<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>-- <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">>Li Wang</span><span lang="EN-US"><o:p></o:p></span></p>
</div>
</div>
</div>
</div>
</div>
</body>
</html>