On Mon, Jan 11, 2010 at 11:17:04AM +0530, Dudhat Dipen-B09055 wrote: > > Hi Ira, > > I have tested your patches with async DMA memcpy support. Though I > haven't captured the improvement figures. > It works fine for RAID5 memcpy offload as interrupts are coming for > separate DMA channels while I have ran IOZONE onto RAID partition. >
Excellent, thanks for running these tests. I'm glad to hear that the RAID offload is working now. You shouldn't notice any difference in performance. On a 32MB memcpy operation, broken into 32x 1MB memcpy(), 1x interrupt(), I noticed less than 0.1% difference (approx 100,000 ns / 0.1ms). This is probably at or near the limits of my measurement accuracy. Ira > Regards, > Dipen > > > -----Original Message----- > From: Dudhat Dipen-B09055 > Sent: Tuesday, January 05, 2010 11:38 AM > To: 'Ira W. Snyder'; dan.j.willi...@intel.com > Cc: ga...@kernel.crashing.org; herb...@gondor.apana.org.au; Tabi > Timur-B04825; linuxppc-...@ozlabs.org; Suresh Vishnu-B05022; Gupta > Maneesh-B18878; Li Yang-R58472 > Subject: RE: fsldma: cleanup driver and fix async_tx compatibility > > > Hi Ira, > > I will test it on 85xx hardware and let you know once done. > > Thanks > Dipen > > > -----Original Message----- > From: Ira W. Snyder [mailto:i...@ovro.caltech.edu] > Sent: Friday, January 01, 2010 11:41 AM > To: dan.j.willi...@intel.com > Cc: ga...@kernel.crashing.org; herb...@gondor.apana.org.au; Tabi > Timur-B04825; linuxppc-...@ozlabs.org; Suresh Vishnu-B05022; Dudhat > Dipen-B09055; Gupta Maneesh-B18878; Li Yang-R58472 > Subject: fsldma: cleanup driver and fix async_tx compatibility > > This patch series cleans up the Freescale DMAEngine driver, including > verifying the locking and making sure that all code paths are correct. > There were a few places that seemed suspicious, and they have been > fixed. > > I have written a quick memory->memory DMAEngine test driver, and the > performance is identical before and after my changes (<0.1% change). I > measured both setting up the DMA operation (via > device_prep_dma_interrupt() and device_prep_dma_memcpy()) and the actual > DMA transfer itself. > > As an added bonus, the interrupt load is measurably reduced. My test > driver transfers 32MB as 32x 1MB chunks + 1 interrupt descriptor, using > the functions noted above. Previous to this patch series, 31 interrupts > were generated. After this patch series, only a single interrupt is > generated for the whole transaction. > > Some testing on 85xx/86xx hardware would be appreciated. Also, some > testing by the users attempting to use async_tx and talitos to handle > RAID offload would be great as well. > > Documentation/powerpc/dts-bindings/fsl/dma.txt | 17 +- > drivers/dma/fsldma.c | 1036 > ++++++++++++------------ > drivers/dma/fsldma.h | 35 +- > 3 files changed, 556 insertions(+), 532 deletions(-) > > Thanks, > Ira > _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
