Re: [PATCH] Native POSIX Thread Library(NPTL) ARM SupportingPatches (1/3)
Dan Kegel <[email protected]>
| Newsgroups | gmane.comp.lib.phil,gmane.comp.lib.glibc.alpha |
|---|---|
| Message-ID | <[email protected]> |
>>I wonder what the performance impact is of having a system call in >>THREAD_SELF. If it turns out to be too great, it may be possible to >>reduce the overhead by adding some more support to the kernel. What >>I've been thinking of is a way for applications to supply a pointer to >>the kernel (via a new system call), and have it store the >>current thread >>ID at that address during context switch. That way, retrieving the >>thread descriptor would be just a regular memory access. This reminds me of vsyscalls. Can someone in the know compare and contrast the current proposal and vsyscalls? Thanks! - Dan p.s. Here's a recent message from around the time they switched the vsyscall page from something created specially by the kernel to a tiny ELF image: http://marc.theaimsgroup.com/?l=linux-kernel&m=105123323202704&w=2 -- Dan Kegel http://www.kegel.com http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045