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Groups > linux.kernel > #1242049
| From | Rameshwar Prasad Sahu <rsahu@apm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH] dmaengine: xgene-dma: Disable memcpy operation due to performance drop |
| Date | 2015-10-08 10:30 +0200 |
| Message-ID | <qheKm-6pG-21@gated-at.bofh.it> (permalink) |
| Organization | linux.* mail to news gateway |
The DMA engine supports memory copy, RAID5 XOR, RAID6 PQ, and other computations. But the bandwidth of the entire DMA engine is shared among all channels. This patch re-configures operations availability such that one can achieve maximum performance for XOR and PQ computation by removing the memory offload operations. Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com> --- drivers/dma/xgene-dma.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c index 8d57b1b..2998fcb 100644 --- a/drivers/dma/xgene-dma.c +++ b/drivers/dma/xgene-dma.c @@ -154,6 +154,7 @@ #define XGENE_DMA_MAX_XOR_SRC 5 #define XGENE_DMA_16K_BUFFER_LEN_CODE 0x0 #define XGENE_DMA_INVALID_LEN_CODE 0x7800000000000000ULL +#undef XGENE_DMA_MEMCPY_ENABLE /* X-Gene DMA descriptor error codes */ #define ERR_DESC_AXI 0x01 @@ -1707,7 +1708,9 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan, dma_cap_zero(dma_dev->cap_mask); /* Set DMA device capability */ +#ifdef XGENE_DMA_MEMCPY_ENABLE dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask); +#endif dma_cap_set(DMA_SG, dma_dev->cap_mask); /* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR -- 1.8.2.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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[PATCH] dmaengine: xgene-dma: Disable memcpy operation due to performance drop Rameshwar Prasad Sahu <rsahu@apm.com> - 2015-10-08 10:30 +0200
Re: [PATCH] dmaengine: xgene-dma: Disable memcpy operation due to performance drop Arnd Bergmann <arnd@arndb.de> - 2015-10-08 11:00 +0200
Re: [PATCH] dmaengine: xgene-dma: Disable memcpy operation due to performance drop Rameshwar Sahu <rsahu@apm.com> - 2015-10-08 11:00 +0200
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