On Sat, 3 Nov 2007, Hugh Dickins wrote:
> I was afraid you might say something like that.
> Perhaps it'll be a patch I need to use in my own builds.
> Though I'd have thought others would want that accuracy too.
> Didn't SLAB give it? (The "r*gr*ss**n" word!)
Slab also only counts objects that are not in the queues. See free_block()
f.e.
We could improve the situation by flushing all cpu slabs before counts are
determined.
Which can be done manually. Run
slabinfo -s
and then look at the numbers.
> > Adds to much overhead to the fast paths
>
> You've come to that conclusion very quickly!
I have just spend a few weeks optimizing the fast and slow paths and there
is some additional overhead that I am still trying to eliminate.
> Any numbers to back it up?
The performance in the fast paths depends on updating only a single word
for an allocation. Adding another counter makes that impossible.
See the recent post on SLUB regression on SMP.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
