[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [PATCH] Native POSIX Thread Library(NPTL) ARM SupportingPatches(1/3)



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




[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]