linux/drivers/dma
Dan Williams c50a898fd4 ioat2: fix performance regression
Commit 0793448 "DMAENGINE: generic channel status v2" changed the interface for
how dma channel progress is retrieved.  It inadvertently exported an internal
helper function ioat_tx_status() instead of ioat_dma_tx_status().  The latter
polls the hardware to get the latest completion state, while the helper just
evaluates the current state without touching hardware.  The effect is that we
end up waiting for completion timeouts or descriptor allocation errors before
the completion state is updated.

iperf (before fix):
[SUM]  0.0-41.3 sec   364 MBytes  73.9 Mbits/sec

iperf (after fix):
[SUM]  0.0- 4.5 sec   499 MBytes   940 Mbits/sec

This is a regression starting with 2.6.35.

Cc: <stable@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Maciej Sosnowski <maciej.sosnowski@intel.com>
Reported-by: Richard Scobie <richard@sauce.co.nz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-10-13 15:43:10 -07:00
..
ioat ioat2: fix performance regression 2010-10-13 15:43:10 -07:00
ipu DMAENGINE: extend the control command to include an arg 2010-05-17 16:30:42 -07:00
ppc4xx of/device: Replace struct of_device with struct platform_device 2010-08-06 09:25:50 -06:00
Kconfig Merge branches 'master' and 'devel' into for-linus 2010-08-10 23:17:52 +01:00
Makefile dmaengine: Driver for Topcliff PCH DMA controller 2010-08-04 14:12:05 -07:00
at_hdmac.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx 2010-08-09 21:00:07 -07:00
at_hdmac_regs.h at_hdmac: implement a private tx_list 2009-09-08 17:53:03 -07:00
coh901318.c DMAENGINE: add runtime slave control to COH 901 318 v3 2010-08-04 14:15:44 -07:00
coh901318_lli.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
coh901318_lli.h tree-wide: Assorted spelling fixes 2010-02-09 11:13:56 +01:00
dmaengine.c Merge branch 'ioat' into dmaengine 2010-05-17 16:30:58 -07:00
dmatest.c dma: dmatest: fix potential sign bug 2010-08-04 14:27:47 -07:00
dw_dmac.c DMAENGINE: extend the control command to include an arg 2010-05-17 16:30:42 -07:00
dw_dmac_regs.h dw_dmac: implement a private tx_list 2009-09-08 17:53:02 -07:00
fsldma.c of/device: Replace struct of_device with struct platform_device 2010-08-06 09:25:50 -06:00
fsldma.h fsldma: major cleanups and fixes 2010-02-02 14:51:42 -07:00
intel_mid_dma.c intel_mid: Add Mrst & Mfld DMA Drivers 2010-07-27 23:32:57 -07:00
intel_mid_dma_regs.h intel_mid: Add Mrst & Mfld DMA Drivers 2010-07-27 23:32:57 -07:00
iop-adma.c Merge branch 'ioat' into dmaengine 2010-05-17 16:30:58 -07:00
iovlock.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
mpc512x_dma.c of/device: Replace struct of_device with struct platform_device 2010-08-06 09:25:50 -06:00
mv_xor.c dmaengine: fix interrupt clearing for mv_xor 2010-09-23 14:14:22 -07:00
mv_xor.h mv_xor: implement a private tx_list 2009-09-08 17:53:03 -07:00
pch_dma.c DMAENGINE: pch_dma: kill another usage of __raw_{read|write}l 2010-08-04 22:08:45 -07:00
pl330.c DMA: PL330: Add dma api driver 2010-05-23 20:28:19 -07:00
shdma.c dma/shdma: move dereference below the NULL check 2010-09-22 15:29:17 -07:00
shdma.h dmaengine: shdma: Introduce include/linux/sh_dma.h 2010-03-23 17:20:06 +09:00
ste_dma40.c DMAENGINE: add runtime slave config to DMA40 v3 2010-08-04 14:14:05 -07:00
ste_dma40_ll.c DMAENGINE: ste_dma40: allocate LCLA dynamically 2010-06-22 18:01:55 -07:00
ste_dma40_ll.h DMAENGINE: ste_dma40: allocate LCLA dynamically 2010-06-22 18:01:55 -07:00
timb_dma.c drivers/dma: Eliminate a NULL pointer dereference 2010-07-01 02:27:35 -07:00
txx9dmac.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx 2010-05-21 17:05:46 -07:00
txx9dmac.h txx9dmac: implement a private tx_list 2009-09-08 17:53:03 -07:00