search for: aio_complet

...odern NIC cards now mostly have the header split feature. The NIC queue pair then may directly DMA the payload into the user spaces mapped payload buffers. Thus a zero-copy for payload is implemented in packet receiving. 7) The TUN/TAP driver manually copy the host header to space user mapped. 8) aio_complete() to notify the Virtio-net backend service for io_getevents(). To guest Virtio-net driver, packets send corresponding to asynchronous write I/O requests of backend. The path is similar to packet receive. 1) Guest Virtio-net driver provides header and payload address filled with contents through...

...odern NIC cards now mostly have the header split feature. The NIC queue pair then may directly DMA the payload into the user spaces mapped payload buffers. Thus a zero-copy for payload is implemented in packet receiving. 7) The TUN/TAP driver manually copy the host header to space user mapped. 8) aio_complete() to notify the Virtio-net backend service for io_getevents(). To guest Virtio-net driver, packets send corresponding to asynchronous write I/O requests of backend. The path is similar to packet receive. 1) Guest Virtio-net driver provides header and payload address filled with contents through...

...his seems fine at first glance[1] "res is the usual result of an I/O operation: the number of bytes transfered, or a negative error code. res2 is a second status value which will be returned to the user" Except that "currently (2.6.0-test9), callers of aio_complete() within the kernel always set res2 to zero." And this hasn''t changed anytime since 2.6.0, so by passing through the status from ''res2'', the callback thinks the I/O operation succeeded even when it failed :-( The fix is simple instead of passin...

i_alloc_sem has always been a bit of an odd "lock". It''s the only remaining rw_semaphore that can be released by a different thread than the one that locked it, and it''s use case in the core direct I/O code is more like a counter given that the writers already have external serialization. This series removes it in favour of a simpler counter scheme, thus getting rid