On 1/22/25 23:49, Askar Safin wrote:
---- On Sun, 19 Jan 2025 07:03:51 +0400 Pavel Begunkov wrote --- > I also wonder, if copying the page table is a performance problem, why > CLONE_VM + exec is not an option? Do you mean CLONE_VFORK? Anyway, CLONE_VM surprisingly turns out
No, vfork is troublesome. What I mean is a task that shares the page table, or in other words a vfork that doesn't block and has a dedicated stack.
to be a good solution. So thank you! There is a bug in libc or in Linux: https://sourceware.org/bugzilla/show_bug.cgi?id=32565 . I suspect this is actually a Linux bug. After receiving your letter I decided to try CLONE_VM. And it works! There is no bug in CLONE_VM version! You can see more details here: https://www.openwall.com/lists/musl/2025/01/22/1
I haven't looked at the bug, but IIUC fundamentally posix_spawn() does the same thing, and if so it's likely that any problem you have with posix_spawn() could be triggered for your hand crafted version. -- Pavel Begunkov
