Re: clone() <-> getpid() bug in 2.6?

[Robert Love]

On Sat, 2004-06-05 at 14:13 -0700, Linus Torvalds wrote:

> Uli, if Arjan is right, then please fix this. It's a buggy and pointless 
> optimization. Anybody who optimizes purely for benchmarks should be 
> ashamed of themselves.

Eh, it definitely does, in nptl/sysdeps/unix/sysv/linux/getpid.c:

	pid_t result = THREAD_GETMEM (THREAD_SELF, pid);
	if (__builtin_expect (result <= 0, 0))
	  result = really_getpid (result);

A few places, including the fork code, fix it:

	/* Adjust the PID field for the new process.  */
	THREAD_SETMEM (self, pid, THREAD_GETMEM (self, tid));

But not direct calls to clone(2).

	Robert Love


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