Re: [patch] Inline vm_acct_memory

[Ravikiran G Thirumalai <kiran@in.ibm.com>]

On Wed, May 28, 2003 at 07:23:30PM -0700, Andrew Morton wrote:
>... 
> Maybe I'm wrong.  kernbench is not some silly tight-loop microbenchmark. 
> It is a "real" workload: gcc.
> 
> The thing about pagetable setup and teardown is that it tends to be called
> in big lumps: for a while the process is establishing thousands of pages
> and then later it is tearing down thousands.  So the cache-thrashing impact
> of having those eighteen instances sprinkled around the place is less
> than it would be if they were all being called randomly.  If you can believe
> such waffle.
> 
> Kiran, do you still have the raw data available?  profiles and runtimes?

Yeah I kinda overlooked vm_unacct_memory 'til I wondered why I had put
the inlines in the header file earlier :).  But I do have the profiles
and checking on all calls to vm_unacct_memory, I find there is no 
regression at significant callsites.  
I can provide the detailed profile if required,
but here is the summary for 4 runs of kernbench -- nos against routines
are profile ticks (oprofile) for 4 runs.


Vanilla
-------
vm_enough_memory 786 778 780 735
vm_acct_memory	870 952 884 898
-----------------------------------
tot of above    1656 1730 1664 1633

do_mmap_pgoff 	3559 3673 3669 3807
expand_stack	27 34 33 42
unmap_region	236 267 280 280
do_brk		594 596 615 615
exit_mmap	51 52 44 52	
mprotect_fixup	47 55 55 57
do_mremap	0 2 1 1
shmem_notify_change 0 0 0 0
shmem_notify_change 0 0 0 0	
shmem_delete_inode  0 0 0 0
shmem_file_write 0 0 0 0	
shmem_symlink  0 0 0 0
shmem_file_setup 0 0 0 0
sys_swapoff	0 0 0 0
poll_idle	101553 108687 89281 86251

Inline
------
vm_enough_memory 1539 1488 1488 1472
do_mmap_pgoff 	3510 3523 3436 3475
expand_stack	27 33 32 27
unmap_region	295 340 311 349
do_brk		641 583 659 640
exit_mmap	33 52 44 42
mprotect_fixup	54 65 73 64
do_mremap	2 0 0 0
shmem_notify_change 0 0 0 0
shmem_notify_change 0 0 0 0	
shmem_delete_inode  0 0 0 0
shmem_file_write 0 0 0 0	
shmem_symlink  0 0 0 0
shmem_file_setup 0 0 0 0
sys_swapoff	0 0 0 0
poll_idle	98733 85659 104994 103096


Thanks,
Kiran