cvs commit: src/sys/i386/include tls.h src/gnu/usr.bin/cc34/cc_prep/config dragonfly-spec.h src/gnu/usr.bin/cc34/cc_prep/config/i386 dragonfly.h src/lib/csu/i386 crt1.c src/lib/libc/gen tls.c src/lib/libc/i386/sys cerror.S src/lib/libc/include libc_private.h ...

David Xu davidxu at
Wed May 11 23:37:41 PDT 2005

Matthew Dillon wrote:
:I need fast critical section, otherwise I can just use sigprocmask
:everywhere, the critical section has to be per-thread based, a
:shared memory page won't work. one thread blocking signal shouldn't
:stop other threads to process signal.
:David Xu
    Well, each thread could have its own block of memory.  But that could
    add up fairly quickly.
I don't think it is cheap on x86 architecture.

    A TCB based critical section is certainly reasonable, and easy for the
    kernel to access.
    Another option would be to implement a code path critical section.
    Basically we would inform the kernel not to interrupt userland if
    the userland instruction pointer is within a specified range of
    addresses.  This would also be easy to implement.
I don't like the idea. Thread library also wants to use the critical
region, and maybe .mcount() based profiling code also wants this.
					Matthew Dillon 
					<dillon at xxxxxxxxxxxxx>
David Xu

More information about the Commits mailing list