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
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 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
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.
Although we do not have the full ACPI information parsed yet, to
announce non-PCI devices derived from the ACPI tables, the device
description of the assumed devices is now integral-part of pci_decode.
Formerly, the information was gained separatedly as boot-module, whereby
we lost synchronization in between ACPI/PCI parsing, BIOS handover, and
PS/2 emulation code already acting.
This recipe combines the dummy_rtc_drv, which consumes a given time,
and provides the "Rtc" service to its clients with the simple NTP client,
which provides the current time to the RTC driver in regular intervals.
Ref genodelabs/genode#4687
Test to trigger periodically ACPI suspend and resume and periodically
trying to restart graphic driver.
Tested successfully with X201 and T420.
Issue #4669
It looks like http://www.elm-chan.org is blocking certain IP ranges,
because downloading the source archive on certain machines fails with
"403 Forbidden".
Fixesgenodelabs/genode#4623
There is one binder with one memory zone per OpenGL context. The patch was
needed before because Genode didn't have proper context support (separate page
tables) leading to binders from one or more context being allocated to the same
GPU address with the same page tables. This was clearly an error and is fixed
with context support.
issue #4664
To prevent caching side-effects of USB DMA memory taken from the packet stream
all allocations of USB packets need to be on separated cachelines at least.
Fixgenodelabs/genode#4655
The tar.gz archive of version 2.4.9 vanished from sourceforge. As the
project moves to GitHub currently and the archive of 2.4.9 is still
available there, just update the download location.
Content and hashes did not change.
If `select_from_ports` is evaluated lazily, we might miss a port during
the dependency check. A way to prevent this is to use the `:=` operator.
Fixesgenodelabs/genode#4618
