linux/arch/powerpc/platforms
Anton Blanchard b4c3a8729a powerpc/iommu: Implement IOMMU pools to improve multiqueue adapter performance
At the moment all queues in a multiqueue adapter will serialise
against the IOMMU table lock. This is proving to be a big issue,
especially with 10Gbit ethernet.

This patch creates 4 pools and tries to spread the load across
them. If the table is under 1GB in size we revert back to the
original behaviour of 1 pool and 1 largealloc pool.

We create a hash to map CPUs to pools. Since we prefer interrupts to
be affinitised to primary CPUs, without some form of hashing we are
very likely to end up using the same pool. As an example, POWER7
has 4 way SMT and with 4 pools all primary threads will map to the
same pool.

The largealloc pool is reduced from 1/2 to 1/4 of the space to
partially offset the overhead of breaking the table up into pools.

Some performance numbers were obtained with a Chelsio T3 adapter on
two POWER7 boxes, running a 100 session TCP round robin test.

Performance improved 69% with this patch applied.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-03 14:14:48 +10:00
..
8xx Disintegrate asm/system.h for PowerPC 2012-03-28 18:30:02 +01:00
40x Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-01-08 13:21:22 -08:00
44x powerpc/44x: Fix PCI MSI support for Maui APM821xx SoC and Bluestone board 2012-05-03 08:49:31 -04:00
52xx powerpc: Mark const init data with __initconst instead of __initdata 2012-04-02 14:00:03 +10:00
82xx Disintegrate asm/system.h for PowerPC 2012-03-28 18:30:02 +01:00
83xx Disintegrate asm/system.h for PowerPC 2012-03-28 18:30:02 +01:00
85xx powerpc/85xx: don't call of_platform_bus_probe() twice 2012-04-19 14:43:27 -05:00
86xx Merge remote-tracking branch 'kumar/next' into merge 2012-04-02 13:57:46 +10:00
512x irq_domain/powerpc: constify irq_domain_ops 2012-02-16 06:11:24 -07:00
amigaone pcspkr: Cleanup Kconfig dependencies 2011-06-09 15:01:41 +02:00
cell powerpc/iommu: Implement IOMMU pools to improve multiqueue adapter performance 2012-07-03 14:14:48 +10:00
chrp powerpc/mpic: Remove duplicate MPIC_WANTS_RESET flag 2012-02-23 10:50:00 +11:00
embedded6xx Disintegrate asm/system.h for PowerPC 2012-03-28 18:30:02 +01:00
maple Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
pasemi Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
powermac Merge branch 'merge' into next 2012-05-09 10:57:57 +10:00
powernv Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
prep powerpc: drop unused Kconfig symbols 2011-10-31 23:39:52 +01:00
ps3 powerpc/ps3: Minor Kconfig cleanup 2012-04-24 15:34:19 -07:00
pseries powerpc/pseries: Disable interrupts around IOMMU percpu data accesses 2012-07-03 14:14:46 +10:00
wsp Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
fsl_uli1575.c Disintegrate asm/system.h for PowerPC 2012-03-28 18:30:02 +01:00
Kconfig powerpc: add support for MPIC message register API 2012-03-16 16:15:28 -05:00
Kconfig.cputype Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2012-05-23 09:02:42 -07:00
Makefile powerpc: Remove the main legacy iSerie platform code 2012-03-09 10:35:11 +11:00