Hi Jens, Can you refer to my reply? Currently the test-iosched is our only option for testing the eMMC4.5 features on a HS200 eMMC card. Thanks, Maya On Thu, August 2, 2012 6:16 am, merez@xxxxxxxxxxxxxx wrote: > > On Tue, July 31, 2012 8:46 am, Jens Axboe wrote: >> On 07/31/2012 04:36 PM, merez@xxxxxxxxxxxxxx wrote: >>> Hi Jens, >>> >>> Do you have comments on this patch? >>> Can we push it to kernel 3.6 version? >> >> I have questions - what is this good for? In other words, explain to me >> why this is useful code. And in particular why this cannot be done from >> userspace with bsg and block tracing? >> >> IOW, I'm dubious as to whether a new _io scheduler_ is the correct >> solution to the problem you have at hand. >> >> -- >> Jens Axboe >> >> > > The test scheduler allows us to control the dispatched requests and their > order without an interfering of other requests. > You can review the patches which depends on this patch in order to better > understand how it is used. > For example, in the eMMC4.5 packed commands feature, the MMC layer can > pack read or write requests (the packed requests must be of the same > direction). MMC layer will stop fetching the requests in case the packing > conditions are broken. > In order to test this feature we had to have a full control on the > requests that the MMC layer fetches and their order, so that we will be > able to determine if the expected behavior was actually achieved. > The test-iosched can call specific block device callbacks, for example for > checking the test results. > Also, in order to be able to run out tests on the main eMMC card that runs > in HS200, we cannot "shut down" the real FS requests, otherwise our phone > won't come up or crash. > The test-iosched allows us to delay the real FS requests until the end of > the test, therefore the tests can be done on the main eMMC card. > > We chose not to use blocktrace due to the "real" FS requests interference > in the middle of the test. > > I'm not familiar with bsg so I cannot tell if it can answer all the > requirements I specified above. > > Thanks, > Maya > > -- > Sent by consultant of Qualcomm Innovation Center, Inc. > Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum > > -- Sent by consultant of Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
