Linked by nfeske on Thu 23rd Aug 2012 08:30 UTC
OSNews, Generic OSes The just released version 12.08 of the Genode OS Framework comes with the ability to run Genode-based systems on ARM hardware without an underlying kernel, vastly improves the support for the NOVA hypervisor, and adds device drivers for the OMAP4 SoC. Further functional additions are a FFAT-based file system service, the port of the lighttpd web server, and support for on-target debugging via GDB.
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RE[2]: Good Progress
by Alfman on Fri 24th Aug 2012 18:00 UTC in reply to "RE: Good Progress"
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I think there'd be merit in having base-hw on x86 given the widespread availability of off the shelf hardware.. but of course you gotta focus with what matters to you.

System programming jobs have become rare here, I've always thought it would be so much fun to land a job working on an alternative operating system instead of just doing it as a hobby.

So anyway, back on topic, I read this in your release notes:

"We complemented our C runtime with support for the pread, pwrite, readv, and writev functions. The pread and pwrite functions are shortcuts for randomly accessing different parts of a file. Under the hood, the functions are implemented via lseek and read/write. To provide the atomicity of the functions, a lock guard prevents the parallel execution of either or both functions if called concurrently by multiple threads."

You are implementing these functions (pread/pwrite) with two system calls then? Is there one lock per process, per file descriptor, or something else? Is this lock held in the kernel or in user space? It seems to me like such locks could impose a major synchronization bottleneck on SMP architectures, is there a reason you wouldn't just add new syscalls for pread/pwrite?

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