On Tue, Mar 24, 2015 at 6:29 PM, Christoph Hellwig <h...@lst.de> wrote: > On Sun, Mar 22, 2015 at 04:14:52PM +0800, Ming Lei wrote: >> The raw page allocated in lo_send() can be a highmem page, >> so kmap(page) should be used for read/write on the page. >> >> Also the patch removes kmap()/kunmap() in lo_send() because >> it isn't needed at all. > > The description seems odd, what it seems to do is to shift the > kmap from lo_send into do_lo_send_write. This does not seem
Looks I ignore the fact which kmap() can setup page_address(), so this change isn't needed, please ignore the patch. > very useful as it now means a kmap per segment instead of just > a single one per I/O. What would make more sense is to just > not allocate a highmem page. On 32bit system, this still may cause pressure on page allocation, since requests are handled concurrently now after using workqueue. But it is a good idea to keep kmap() per segment, and will do that in v2. Thanks, Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
