Re: [PATCH v2] Implement close-on-fork
From: Ralph Corderoy <hidden>
Date: 2022-06-19 10:42:41
Also in:
linux-alpha, linux-arch, linux-fsdevel, lkml, sparclinux
From: Ralph Corderoy <hidden>
Date: 2022-06-19 10:42:41
Also in:
linux-alpha, linux-arch, linux-fsdevel, lkml, sparclinux
Hi Matthew, thanks for replying.
quoted
The need for O_CLOFORK might be made more clear by looking at a long-standing Go issue, i.e. unrelated to system(3), which was started in 2017 by Russ Cox when he summed up the current race-condition behaviour of trying to execve(2) a newly created file: https://github.com/golang/go/issues/22315.The problem is that people advocating for O_CLOFORK understand its value, but not its cost. Other google employees have a system which has literally millions of file descriptors in a single process. Having to maintain this extra state per-fd is a cost they don't want to pay (and have been quite vocal about earlier in this thread).
So do you agree the userspace issue is best solved by *_CLOFORK and the problem is how to implement *_CLOFORK at an acceptable cost? OTOH David Laight was making suggestions on moving the load to the fork/exec path earlier in the thread, but OTOH Al Viro mentioned a ‘portable solution’, though that could have been to a specific issue rather than the more general case. How would you recommend approaching an acceptable cost is progressed? Iterate on patch versions? Open a bugzilla.kernel.org for central tracking and linking from the other projects? ..? -- Cheers, Ralph.