cvs commit: src/sys/kern kern_synch.c src/sys/sys proc.h src/sys/i386/i386 genassym.c pmap.c swtch.s src/sys/i386/include pcb.h

[Jeff Roberson]

This improved my 'make kernel' times by 2%.  The effect was less with
buildkernel since we spent so much of our time waiting on IO, etc.  For an
operation like pmap_zero_page() the TLB flush is probably half of the cost
of the function.

On Tue, 30 Sep 2003, Jeff Roberson wrote:

> jeff        2003/09/30 01:11:36 PDT
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/kern             kern_synch.c
>     sys/sys              proc.h
>     sys/i386/i386        genassym.c pmap.c swtch.s
>     sys/i386/include     pcb.h
>   Log:
>    - On my Pentium4-M laptop, invalpg takes ~1100 cycles if the page is found in
>      the TLB and ~1600 if it is not.  Therefore, it is more effecient to
>      invalidate the TLB after operations that use CMAP rather than before.
>    - So that the tlb is invalidated prior to switching off of a processor, we
>      must change the switchin functions to switchout functions.
>    - Remove td_switchout from the thread and move it to the x86 pcb.
>    - Move the code that calls switchout into swtch.s.  These changes make this
>      optimization truely x86 specific.
>
>   Revision  Changes    Path
>   1.143     +1 -1      src/sys/i386/i386/genassym.c
>   1.438     +33 -33    src/sys/i386/i386/pmap.c
>   1.143     +6 -1      src/sys/i386/i386/swtch.s
>   1.50      +2 -1      src/sys/i386/include/pcb.h
>   1.234     +0 -8      src/sys/kern/kern_synch.c
>   1.348     +0 -1      src/sys/sys/proc.h
>