Hello, On Friday, January 28, 2011 8:17 PM Sonasath, Moiz wrote: >>> > This commit add code that flushed page cache disk buffers every 128 read >>> > and write request. It has almost no impact on the performance of the >>> > emulate usb drive but saves system page cache from being filled with >>> > useless emulated disk data. >> Could you also pls confirm the impact of this change on the >> performance of the mass storage device? > There was a similar patch already posted by google on their android tree during k-32 time frame: > http://android.git.kernel.org/?p=kernel/omap.git;a=commit;h=5cf1b82507ed24e0ee9f4f2f3ce6dbcb82b86fa0 > With this patch I observed on OMAP based zoom3 platform almost 50% drop in performance for mass-storage throughput. > If this helps. Thanks for the link. I've observed a little bit lower performance drops on emulated usb disk with my patch, but think that this can be addressed if we manage to force cache flushes to happen asynchronously. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
