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3rdparty/stout/include/stout/os/linux.hpp (line 60)
<https://reviews.apache.org/r/54996/#comment231621>

    I don't think that you need this static constructor. You can do everything 
you need in `allocate`, which is them symmetric with `deallocate`.



3rdparty/stout/include/stout/os/linux.hpp (line 63)
<https://reviews.apache.org/r/54996/#comment231622>

    I'd recommend something like this:
    ```
    Try<Nothing> allocate(size_t nbytes) {
        int error = ::posix_memalign(&address, os::getpagesize(), nbytes);
        if (error) {
            return ErrnoError(error);
        }
        
        return Nothing();
    }
    ```



3rdparty/stout/include/stout/os/linux.hpp (line 75)
<https://reviews.apache.org/r/54996/#comment231625>

    You can simplify this to just:
    ```
    void deallocate() {
      ::free(address);
      
      address = nullptr;
      size = 0;
    }
    ```



3rdparty/stout/include/stout/os/linux.hpp (line 79)
<https://reviews.apache.org/r/54996/#comment231624>

    You can avoid the `reinterpret_cast` by typing this as `void *`. If you add 
the `start()` method suggested below, you can also make it private.



3rdparty/stout/include/stout/os/linux.hpp (line 82)
<https://reviews.apache.org/r/54996/#comment231620>

    You should explictly delete the copy constructors here to ensure the stack 
can't be leaked if the code changes:
    
    ```
    Stack(const Stack&) = delete;
    Stack& operator=(const Stack&) = delete;
    ```



3rdparty/stout/include/stout/os/linux.hpp (line 105)
<https://reviews.apache.org/r/54996/#comment231626>

    Since this magic number appears twice I'd be inclined to hoist it into 
`Stack`:
    ```
    class Stack {
      ...
      static constexpr size_t DefaultSize = 8 * 1024 * 1024;
      ...
    };
    ```



3rdparty/stout/include/stout/os/linux.hpp (line 118)
<https://reviews.apache.org/r/54996/#comment231623>

    Consider hoisting this into the `Stack` class:
    
    ```
    void * Stack::start() {
      return (uint8_t *)address + size;
    }
    ```


- James Peach


On Jan. 4, 2017, 12:26 a.m., Aaron Wood wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/54996/
> -----------------------------------------------------------
> 
> (Updated Jan. 4, 2017, 12:26 a.m.)
> 
> 
> Review request for mesos and Jie Yu.
> 
> 
> Bugs: MESOS-6835
>     https://issues.apache.org/jira/browse/MESOS-6835
> 
> 
> Repository: mesos
> 
> 
> Description
> -------
> 
> Currently in the Linux launcher when the stack is allocated and prepared for 
> a call to clone() it is not properly aligned. This is not an issue for x86 or 
> x64 but for ARM64/AArch64 it is because of the requirement of having the 
> stack aligned to a 16 byte boundary. While x86 and x64 also expect the stack 
> to have a 16 byte aligned stack, it is not enforced. An explanation of the 
> stack and requirements for ARM64 can be found here 
> http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055b/IHI0055B_aapcs64.pdf
>  (specifically section 5.2.2.1 that says SP mod 16 = 0. The stack must be 
> quad-word aligned.)
> 
> Additionally, the way that the stack is currently allocated and passed to 
> clone() accidentally chops off one entry, making a stack overflow using those 
> missing 8 bytes a possibility. Fixing this while aligning the memory will fix 
> both the issue of the stack overflow issue as well as the SIGBUS crash. We 
> should also net better performance from having the stack aligned.
> 
> 
> Diffs
> -----
> 
>   3rdparty/stout/include/stout/os/linux.hpp 530f1a55b 
>   src/linux/ns.hpp 77789717e 
> 
> Diff: https://reviews.apache.org/r/54996/diff/
> 
> 
> Testing
> -------
> 
> Built Mesos from source and am currently running it in a test cluster. 
> Launched both Docker and Mesos tasks via Marathon without any resulting crash 
> (initial crash only happened with Mesos containerizer + linux_launcher, not 
> with the posix_launcher).
> 
> 
> Thanks,
> 
> Aaron Wood
> 
>

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