| Message ID | 1234417660.2604.391.camel@ymzhang |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 12 Feb 2009, Zhang, Yanmin wrote: > The default order of kmalloc-8192 on 2*4 stoakley is an issue of calculate_order. > > > slab_size order name > ------------------------------------------------- > 4096 3 sgpool-128 > 8192 2 kmalloc-8192 > 16384 3 kmalloc-16384 > > kmalloc-8192's default order is smaller than sgpool-128's. You reverted the page allocator passthrough patch before this right? Otherwise kmalloc-8192 should not exist and allocation calls for 8192 bytes would be converted inline to request of an order 1 page from the page allocator.
On Sat, 2009-01-24 at 09:36 +0200, Pekka Enberg wrote: > > > On Fri, 2009-01-23 at 10:22 -0500, Christoph Lameter wrote: > > > >> No there is another way. Increase the allocator order to 3 for the > > > >> kmalloc-8192 slab then multiple 8k blocks can be allocated from one of the > > > >> larger chunks of data gotten from the page allocator. That will allow slub > > > >> to do fast allocs. > > > > > > On Sat, Jan 24, 2009 at 4:55 AM, Zhang, Yanmin > > > <yanmin_zhang@linux.intel.com> wrote: > > > > After I change kmalloc-8192/order to 3, the result(pinned netperf UDP-U-4k) > > > > difference between SLUB and SLQB becomes 1% which can be considered as fluctuation. > > > > > > Great. We should fix calculate_order() to be order 3 for kmalloc-8192. > > > Are you interested in doing that? On Thu, 2009-02-12 at 13:22 +0800, Zhang, Yanmin wrote: > > Pekka, > > > > Sorry for the late update. > > The default order of kmalloc-8192 on 2*4 stoakley is really an issue of calculate_order. On Thu, 2009-02-12 at 13:47 +0800, Zhang, Yanmin wrote: > Oh, previous patch has a compiling warning. Pls. use below patch. > > From: Zhang Yanmin <yanmin.zhang@linux.intel.com> > > The default order of kmalloc-8192 on 2*4 stoakley is an issue of calculate_order. Applied to the 'topic/slub/perf' branch. Thanks! Pekka -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Christoph, On Thu, 12 Feb 2009, Zhang, Yanmin wrote: >> The default order of kmalloc-8192 on 2*4 stoakley is an issue of calculate_order. >> >> >> slab_size order name >> ------------------------------------------------- >> 4096 3 sgpool-128 >> 8192 2 kmalloc-8192 >> 16384 3 kmalloc-16384 >> >> kmalloc-8192's default order is smaller than sgpool-128's. On Thu, Feb 12, 2009 at 5:25 PM, Christoph Lameter <cl@linux-foundation.org> wrote: > You reverted the page allocator passthrough patch before this right? > Otherwise kmalloc-8192 should not exist and allocation calls for 8192 > bytes would be converted inline to request of an order 1 page from the > page allocator. Yup, I assume that's the case here. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- linux-2.6.29-rc2/mm/slub.c 2009-02-11 00:49:48.000000000 -0500 +++ linux-2.6.29-rc2_slubcalc_order/mm/slub.c 2009-02-12 00:47:52.000000000 -0500 @@ -1844,6 +1844,7 @@ static inline int calculate_order(int si int order; int min_objects; int fraction; + int max_objects; /* * Attempt to find best configuration for a slab. This @@ -1856,6 +1857,9 @@ static inline int calculate_order(int si min_objects = slub_min_objects; if (!min_objects) min_objects = 4 * (fls(nr_cpu_ids) + 1); + max_objects = (PAGE_SIZE << slub_max_order)/size; + min_objects = min(min_objects, max_objects); + while (min_objects > 1) { fraction = 16; while (fraction >= 4) { @@ -1865,7 +1869,7 @@ static inline int calculate_order(int si return order; fraction /= 2; } - min_objects /= 2; + min_objects --; } /*