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New elevated privilege system #484
New elevated privilege system #484
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forking means we COW the whole address space which can be really slow when that is large. that would e.g. be the case when you start hotspot, analyze some large file and then rerun the record from there.
is there a way this could use QProcess such that we can leverage vfork/posix_spawn when available? or is there maybe something like that in boost which we could use to get this behavior in a more efficient manner?
see also: https://codereview.qt-project.org/c/qt/qtbase/+/417829
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sure this could be improved. Don't know what's available in boost for that. vfork seems a bit dangerous to me, for posix_spawn I suppose one would need to move this initially-stopped-exec functionality in a separate helper binary or something.
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we can only use vfork if we create a new binary, since vfork only allows for
__exit()
andexec*
calls. I thinkclone
withCLONE_WM | CLONE_VFORK
might be the easiest way to solve this.There was a problem hiding this comment.
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From my understanding, VFORK suspends the calling process until exec is called, which we do not want here at all. I don't think VFORK is usable for this. posix_spawn and a helper process should work though.