<div class="__aliyun_email_body_block"><div  style="clear:both;">Hi, lttng-dev team </div><div  style="clear:both;">   When lttng-sessiond exits, the ust applications should call lttng_ust_objd_table_owner_cleanup() and clean up all shm resource(unmap and close). Howerver I do find that the ust applications keep opening "all" of the shm fds("/dev/shm/ust-shm-consumer-81132 (deleted)") and do NOT free shm.</div><div  style="clear:both;">   If we run lttng-sessiond again, ust applications can get a new piece of shm and a new list of shm fds so double shm usages. Then if we kill lttng-sessiond, what the mostlikely happened is ust applications close the new list of shm fds and free new shm resource but keeping old shm still. In other word, we can not free this piece of shm unless we killing ust applications!!!</div><div  style="clear:both;">  So Is there any possilbe that ust applications failed calling lttng_ust_objd_table_owner_cleanup()? Do you have ever see this problem? Do you have any advice to free the shm without killling ust applications(I tried to dig into kernel shm_open and /dev/shm, but not found any ideas)?</div><div  style="clear:both;"><span  style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;"><br ></span></div><div  style="clear:both;"><span  style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">Thanks in advance</span></div><div  style="clear:both;"><span  style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">zhenyu.ren </span></div><div  style="clear:both;"><br ></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><blockquote  style="margin-right:.0px;margin-top:.0px;margin-bottom:.0px;"><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">------------------------------------------------------------------</span></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">发件人：zhenyu.ren via lttng-dev <lttng-dev@lists.lttng.org></span></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">发送时间：2022年2月23日(星期三) 23:09</span></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">收件人：lttng-dev <lttng-dev@lists.lttng.org></span></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">主　题：[lttng-dev] 回复： shm leak in traced application?</span></div><div  style="clear:both;"><span  style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><div  style="clear:both;">>"I<span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;"> found these items also exist in a traced application which is a long-time running daemon"</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;"> Even if lttng-sessiond has been killed!!</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;"><br ></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">Thanks</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">zhenyu.ren</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">------------------------------------------------------------------</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">发件人：zhenyu.ren via lttng-dev <lttng-dev@lists.lttng.org></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">发送时间：2022年2月23日(星期三) 22:44</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">收件人：lttng-dev <lttng-dev@lists.lttng.org></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">主　题：[lttng-dev] shm leak in traced application?</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><br ></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">Hi, </span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   There are many items such as "/dev/shm/ust-shm-consumer-81132 (deleted)" exist in lttng-sessiond fd spaces. I know it is the result of shm_open() and shm_unlnik() in create_posix_shm(). </span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   However, today, I found these items also exist in a traced application which is a long-time running daemon. The most important thing I found is that there seems no reliable way to release share memory.</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   I tried to kill lttng-sessiond but not always release share memory. Sometimes I need to kill the traced application to free share memory....But it is not a good idea to kill these applications.</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   My questions are: </span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   1. Is there any way to release share memory without killing any traced application?</span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;">   2. Is it normal that many items such as <span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">"</span><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">/dev/shm/ust-shm-consumer-81132 (deleted)" exist in the traced application?</span></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;"><br ></span></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">Thanks</span></span></div><div  style="clear:both;"><span  class=" __aliyun_node_has_color __aliyun_node_has_color" style="font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;color:#000000;"><span  class=" __aliyun_node_has_color __aliyun_node_has_bgcolor __aliyun_node_has_color __aliyun_node_has_bgcolor" style="color:#000000;font-family:Tahoma,Arial,STHeiti,SimSun;font-size:14.0px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;text-align:start;text-indent:.0px;text-transform:none;widows:2;background-color:#ffffff;text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline;">zhenyu.ren</span></span></div><div ><br ></div></blockquote><div ><br ></div></div>