By adding a 'write_ready' interface following the lines of the existing
'read_ready', VFS plugins become able to propagate the (de-)saturation
of I/O buffers to the VFS user. This information is important when using
a non-blocking file descriptor for writing into a TCP socket. Once the
application observes EAGAIN, it expects a subsequent 'select' call to
return as soon as new I/O buffer space becomes available.
Before this patch, the select call would always return under this
condition, causing an unnecessarily busy write loop.
Issue #4697
The new interface is meant to replace the 'Vfs::Io_response_handler'.
In contrast to the 'Io_response_handler', which had to be called
on a 'Vfs_handle', the new interface does not require any specific
'Vfs_handle'. It is merely meant to prompt the VFS user (like the libc)
to re-attempt stalled I/O operations but it does not provide any
immediate hint, about which of the handles have become ready for
reading/writing.
Issue #4697
This patch removes the 'Insufficient_buffer' exception by returning the
WRITE_ERR_WOULD_BLOCK result value instead. It also eliminates the
superfluous WRITE_ERR_AGAIN and WRITE_ERR_INTERRUPT codes.
Issue #4697
The original size of 16K impedes the batched processing of network
packets. Changing the value to 256K reduces the number of context
switches when downloading large files and thereby improves the
throughput by more than 25% (base-hw on qemu_x86_64, using fetchurl
to download a file of 100 MiB via the NIC router from lighttpd).
Issue #4697
This patch fosters the batching of network packets transferred by the
lwIP stack over the NIC connection. It replaces the eager submission of
the packet-stream's data-flow signals by explicit wakeup notifications.
The commit also increases the NIC session's buffer size from 128 to 1024
packets.
Issue #4697
...and tighten constness in adjacent code parts.
The VFS-internal synchronization via mutexes is no longer needed because
the access to the VFS is serialized by the VFS client, i.e., the libc.
Issue #4697
Since the lwip library is used only by the vfs_lwip plugin, this patch
moves the Genode-specific support code local to the VFS plugin, easing
further simplification and allowing for a tighter integration with the
VFS plugin.
The recipes for api/lwip and src/vfs_lwip stay separate as both parts
use different licenses.
Issue #4697
This networking scenario is useful for analysing and optimizing the
interplay of the VFS, libc, TCP/IP, and the NIC router. It downloads a
file via fetchurl from lighttpd, both of which are hosted on a virtual
network.
Issue #4697
This patch facilitates the batching of I/O operations in the VFS library
by replacing the implicit wakeup of remote peer (via the traditional
packet-stream interface like 'submit_packet') by explicit wakeup
signalling.
The wakeup signalling is triggered not before the VFS user settles down.
E.g., for libc-based applications, this is the case if the libc goes
idle, waiting for external I/O.
In the case of a busy writer to a non-blocking file descriptor or socket
(e.g., lighttpd), the remote peers are woken up once a write operation
yields an out-count of 0.
The deferring of wakeup signals is accommodated by the new 'Remote_io'
mechanism (vfs/remote_io.h) that is designated to be used by all VFS
plugins that interact with asynchronous Genode services for I/O.
Issue #4697
This test reveals the patters of the batching of consecutive write
operations on a file-system session. It issues 100 writes of one byte
each, which should ideally result in large batches of operations
submitted to the file-system session at once.
The run script performs the write operations through a chain of two VFS
servers, thereby exercising the write batching of both the libc and the
intermediate VFS server.
Issue #4697
By replacing the calls of 'acknowledge_packet' and 'get_packet' with
'try_ack_packet' and 'try_get_packet', we avoid the implicit triggering
of data-flow signals. Instead, the VFS server now relies on explicit
calls of the packet stream's 'wakeup' interface.
Issue #4697
The change of the queue size from 16 to 32 has negligible costs (4 KiB
instead of 2 KiB for the packet-stream queues) while facilitating the
batching of many small consecutive write operations.
Issue #4697
Some signal-heavy scenarios (e.g., libc_integration) produced the
following warning that hinted a data race on signal data in the context
object.
Warning: returning signal with num == 0
The cause was the use of Signal_context::local_submit() in the libc
introduced in
424ed1b79a libc: remove Reconstructible / use local_submit in kernel
in combination with a missing context-mutex aquisition resulting in a
data race on Signal_context::_curr_signal.
Issue #3923
Both modules were quite similar except the the name of the FIT image
(image.itb) and the mkimage command line. FIT images are now produced by
the following RUN_OPT.
RUN_OPT += --include image/uboot --image-uboot-fit
Issue #4693
By making the use of gzip's '--best' option configurable and disabling it
by default, this patch noticably reduces the built-test cycle from 15 to
10 seconds when integrating the Sculpt system image for the PinePhone.
Fixes#4693
The commit "sculpt_manager: relax nic_drv policy label" introduced the use of
the "label_prefix" attribute instead of "label" for the uplink policy in the
NIC router. However, it missed an appropriate adaption of the lookup of that
attribute when the Sculpt manager has to decide which uplink is used in a
manually managed router config. This caused the uplink to disappear whenever a
user created a manually managed router config. This commit fixes the problem.
Issue #4660Fixes#4695
This prevents errors like the following during parallel builds.
MERGE ld-hw.abi.so
/usr/local/genode/tool/21.05/bin/genode-arm-ld:symbol.map:0: syntax error in VERSION script
Replace usb_kill_urb() by usb_unlink_urb() in the timeout handler for
control URBs, as usb_kill_urb() may block and is not allowed to be
called in IRQ/bottom half contexts.
Fixes#4681
Count more accurately how much packets are in flied, and whether
new packets can be handled. Moreover, catch potential exceptions
whenever acknowledging a packet, and warn about the lost acknowledgement.
Fixgenodelabs/genode#4678
There is at least one client that performs DRM calls from multiple
pthreads, which is not supported for now. We guard the concurrent
access by grabbing a pthread_mutex before each operation.
This commit circumvents faulty behaviour of base-pistachio, if
the PCI config space gets requested megabyte-wise. It occurs that
we get a mapping sequence in between sigma0, core and component,
like the following: 0xe1000000 => 0xbf001000 => 0x10b000,
with the consequence that the component stalls when accessing
the latter one. By requesting I/O memory aligned to the size,
the faulty behaviour vanishes.
Ref #4686
This is required for scenarios in which a device appears at a later
point in time. If the ROM is not updated, the device_by_type() method may
operate on an outdated dataspace and never find the device it is waiting for.
