> On July 27, 2016, 10:05 a.m., Qian Zhang wrote: > > src/slave/containerizer/mesos/isolators/cgroups/subsystem.cpp, line 494 > > <https://reviews.apache.org/r/49851/diff/5/?file=1453262#file1453262line494> > > > > How do we recover this field `updatedLimit`? I mean during agent > > recovery, `updatedLimit` of each Info will be reset to `false`, right? But > > I think that is not correct. > > haosdent huang wrote: > I think this problem exists at `mem.cpp` as well, and update the limit > twice here does not bring problems here. So I drop this. Feel free to reopen > this if you think it would bring problems here. > > Qian Zhang wrote: > Yes, it is also a bug in `mem.cpp` which uses `info->pid` to check if it > is the first time to update the memory limit, but the value of `info->pid` > will also be lost during agent recovery. > > And I think updating the memory hard limit twice will bring some > problems, as mentioned in this comments > (https://github.com/apache/mesos/blob/1.0.0/src/slave/containerizer/mesos/isolators/cgroups/mem.cpp#L369:#L371), > decreasing memory hard limit may induce an OOM. > > I had a discussion with Jie on this issue, and his suggestion is that we > should not use such kind of field (e.g., `pid` or `updatedLimit`) because > they can not be recovered, instead, before updating the hard limit, we should > check if its current value is still the initial value (should be -1? And it > may be different in different Linux distributions, so you may need to double > check it), if it is, then that means it is the first time to update the hard > limit, then we can just update it, if it is not, then that means it is not > the first time, then we can only increase it but not decrease it. > > haosdent huang wrote: > Thank you for your help. The initial value of limit_in_bytes is -1 > (unlimited). Let's update to check by this. > > haosdent huang wrote: > Refer to http://lxr.free-electrons.com/source/kernel/res_counter.c?v=3.10 > , http://lxr.free-electrons.com/source/kernel/res_counter.c?v=3.12 and > http://lxr.free-electrons.com/source/include/linux/page_counter.h > > There are two possible value of the initail values of `limit_in_bytes`: > 9223372036854775807 (LONG_MAX) and 18446744073709551615 (ULONG_MAX).
I see the third value of it in Ubuntu 16.04: ``` cat /sys/fs/cgroup/memory/memory.limit_in_bytes 9223372036854771712 ``` We need to cover it as well? - Qian ----------------------------------------------------------- This is an automatically generated e-mail. To reply, visit: https://reviews.apache.org/r/49851/#review143517 ----------------------------------------------------------- On Aug. 7, 2016, 12:26 p.m., haosdent huang wrote: > > ----------------------------------------------------------- > This is an automatically generated e-mail. To reply, visit: > https://reviews.apache.org/r/49851/ > ----------------------------------------------------------- > > (Updated Aug. 7, 2016, 12:26 p.m.) > > > Review request for mesos, Gilbert Song, Jie Yu, Qian Zhang, and Zhengju Sha. > > > Bugs: MESOS-5045 > https://issues.apache.org/jira/browse/MESOS-5045 > > > Repository: mesos > > > Description > ------- > > Implemented `MemorySubsystem`. > > > Diffs > ----- > > src/slave/containerizer/mesos/isolators/cgroups/cgroups.hpp > b191b2a52a9645fc902a35ed52909b2142f0b4c0 > src/slave/containerizer/mesos/isolators/cgroups/cgroups.cpp > 2659252d8cffcefc233bc85fb4707c8147272737 > src/slave/containerizer/mesos/isolators/cgroups/constants.hpp > c45d88092f3fe497373dfeaa8346aef9126c7b8b > src/slave/containerizer/mesos/isolators/cgroups/subsystem.hpp > 5f52a076a1fa3a21d886cb961ddeed5046a38d7c > src/slave/containerizer/mesos/isolators/cgroups/subsystem.cpp > a30ecafcbecc9d3b6eeea2b04dcb4d278750af41 > > Diff: https://reviews.apache.org/r/49851/diff/ > > > Testing > ------- > > > Thanks, > > haosdent huang > >
