Thanks a lot for reply. I do not reply it in bug tracker since I have not gotten a reliable way to reproduce the leak case. ------------------------------------------------------------------ 发件人：Mathieu Desnoyers 发送时间：2022年3月8日(星期二) 23:26 收件人：zhenyu.ren 抄　送：Jonathan Rajotte ; lttng-dev 主　题：Re: [lttng-dev] 回复： 回复： 回复： shm leak in traced application? ----- On Mar 8, 2022, at 12:18 AM, lttng-dev lttng-dev@lists.lttng.org wrote: > Hi, > In shm_object_table_append_shm()/alloc_shm()， why not calling FD_CLOEXEC fcntl() > to shmfds? I guess this omission leads to shm fds leak. Those file descriptors are created when received by ustcomm_recv_fds_unix_sock, and immediately after creation they are set as FD_CLOEXEC. We should continue this discussion in the bug tracker as suggested by Jonathan. It would greatly help if you can provide a small reproducer. Thanks, Mathieu > Thanks > zhenyu.ren >> ------------------------------------------------------------------ >> 发件人：Jonathan Rajotte-Julien >> 发送时间：2022年2月25日(星期五) 22:31 >> 收件人：zhenyu.ren >> 抄 送：lttng-dev >> 主 题：Re: [lttng-dev] 回复： 回复： shm leak in traced application? >> Hi zhenyu.ren, >> Please open a bug on our bug tracker and provide a reproducer against the latest >> stable version (2.13.x). >> https://bugs.lttng.org/ >> Please follow the guidelines: https://bugs.lttng.org/#Bug-reporting-guidelines >> Cheers >> On Fri, Feb 25, 2022 at 12:47:34PM +0800, zhenyu.ren via lttng-dev wrote: >> > Hi, lttng-dev team >>> 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. >>> 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!!! >>> 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)? >> > Thanks in advance >> > zhenyu.ren >> > ------------------------------------------------------------------ >> > 发件人：zhenyu.ren via lttng-dev >> > 发送时间：2022年2月23日(星期三) 23:09 >> > 收件人：lttng-dev >> > 主 题：[lttng-dev] 回复： shm leak in traced application? >>> >"I found these items also exist in a traced application which is a long-time >> > >running daemon" >> > Even if lttng-sessiond has been killed!! >> > Thanks >> > zhenyu.ren >> > ------------------------------------------------------------------ >> > 发件人：zhenyu.ren via lttng-dev >> > 发送时间：2022年2月23日(星期三) 22:44 >> > 收件人：lttng-dev >> > 主 题：[lttng-dev] shm leak in traced application? >> > Hi, >>> 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(). >>> 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. >>> 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. >> > My questions are: >>> 1. Is there any way to release share memory without killing any traced >> > application? >>> 2. Is it normal that many items such as "/dev/shm/ust-shm-consumer-81132 >> > (deleted)" exist in the traced application? >> > Thanks >> > zhenyu.ren >> > _______________________________________________ >> > lttng-dev mailing list >> > lttng-dev@lists.lttng.org >> > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev >> -- >> Jonathan Rajotte-Julien >> EfficiOS > _______________________________________________ > lttng-dev mailing list > lttng-dev@lists.lttng.org > https://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com