Messages in this thread | | | From | "Sosnowski, Maciej" <> | Date | Fri, 12 Dec 2008 14:27:57 +0000 | Subject | RE: [PATCH 00/13] dmaengine redux |
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Williams, Dan J wrote: > The dmaengine subsystem collects and advertises dma channels for two > classes of users in the kernel, memory-to-memory offload and > traditional device-to-memory DMA. The original design was driven by > the memory-to-memory case and is starting to show its limitations now > that more device-to-memory DMA users are being planned. The primary > difference between the two classes is that memory-to-memory offload > is very amenable to channel sharing and is tolerant of dynamic > channel changes. Compare this to the device-to-memory case where a > channel must be dedicated to a device and may have platform-specific > reasons why it cannot talk to a different device. > > This rework allows channels to be targeted to a public (mem-to-mem) > pool or be reserved for an exclusive private (dev-to-mem) allocation. > See [PATCH 1/13] for documentation of the changes. A nice side > effect of the rework is: > > 24 files changed, 679 insertions(+), 1108 deletions(-) > > All review welcomed, especially around the dma_slave changes, or > performance impacts of dma_find_channel. > > These patches are currently on async_tx.git/upstream, and barring any > brown-paper-bag issues will move to linux-next via async_tx.git/next. > > git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx.git > upstream > > --- > Dan Williams (13): > dmaengine: kill enum dma_state_client > dmaengine: remove 'bigref' infrastructure > dmaengine: kill struct dma_client and supporting infrastructure > dmaengine: replace dma_async_client_register with dmaengine_get > atmel-mci: convert to dma_request_channel and down-level > dma_slave dmatest: convert to dma_request_channel > dmaengine: introduce dma_request_channel and private channels > net_dma: convert to dma_find_channel > dmaengine: provide a common 'issue_pending_all' implementation > dmaengine: centralize channel allocation, introduce > dma_find_channel dmaengine: up-level reference counting to the > module level dmaengine: remove dependency on async_tx > async_tx, dmaengine: document channel allocation and api rework > > Documentation/crypto/async-tx-api.txt | 135 +++---- > Documentation/dmaengine.txt | 1 > arch/avr32/include/asm/atmel-mci.h | 6 > arch/avr32/mach-at32ap/at32ap700x.c | 15 - > crypto/async_tx/async_tx.c | 350 ------------------ > drivers/dma/Kconfig | 2 > drivers/dma/dmaengine.c | 637 > +++++++++++++++++++++++---------- drivers/dma/dmatest.c > | 111 ++---- drivers/dma/dw_dmac.c | 28 - > drivers/dma/fsldma.c | 3 > drivers/dma/ioat_dma.c | 5 > drivers/dma/iop-adma.c | 11 - > drivers/dma/mv_xor.c | 11 - > drivers/mmc/host/atmel-mci.c | 103 +---- > include/linux/async_tx.h | 17 - > include/linux/dmaengine.h | 148 ++------ > include/linux/dw_dmac.h | 31 +- > include/linux/netdevice.h | 3 > include/net/netdma.h | 11 - > net/core/dev.c | 148 -------- > net/ipv4/tcp.c | 5 > net/ipv4/tcp_input.c | 2 > net/ipv4/tcp_ipv4.c | 2 > net/ipv6/tcp_ipv6.c | 2 > 24 files changed, 679 insertions(+), 1108 deletions(-) > create mode 100644 Documentation/dmaengine.txt
Dan,
First of all sorry for delay in my feedback on this. I have been absent for couple of weeks and last days I was struggling with some ioatdma hot issues.
I have walked through these patches and generally I like the whole redesign/reduction idea. There are couple of concerns/questions (+ minor comments) from my side to three of these patches: 3, 7 and 11. I will send them in a minute. The rest of them looks good to me at this point.
Next week I am planning to run some tests on my I/OAT setup, to see how this new dmaengine would behave in this environment. I will let you know.
Regards, Maciej
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