On Tue, Sep 4, 2012 at 9:01 PM, ikjtel <ikj12...@yahoo.com> wrote: > > >> Yes, looks like it. But it's an Atom, which might change things. I > >> know we had some issues on Atom's before, but I thought that we worked >> them out. I'll be interested to see how cmake reports the architecture >> checks for VOLK here. > > Hi Tom > > I've made some further progress, and this may be premature, but I'll go so > far as to say we can rule this out entirely. > > Here's a strawman theory - criticism of the theory is invited, shooting it > down would be welcomed ; ) > > Our app uses lots of disconnect() and connect() calls because our appetite > for widgets is bigger than the CPU available. Also, since the widgets are > tab-selectable there is only one widget visible at a time. So when the user > hits a tab we call disconnect and connect (surrounded by lock() / unlock() of > course) in order to dynamically create a flow graph that connects up all the > elements needed by that tab (and disconnects the elements, filters, demods, > FFT's and other blocks that aren't needed by this tab, to conserve CPU. > > The theory is that this is "messing up" the boundary alignments of the > operands to the SSE instructions, making them no longer properly aligned, > resulting in a GPF. > > Here's the minimal python app , it seg faults in volk 100% reliably for me. > If the call to shuffle() is removed, the script does not crash. > > Max
Max, That's not a bad theory as I've run into the same situation before. I had a fix for that, though, back before the release of 3.6.0. It's possible that it's more complicated, though. I'll use your script to see if I can do more to figure it out. Tom > p.s. kindly let me know if this code isn't properly machine-readable > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > #!/usr/bin/env python > import math > import time > from gnuradio import gr, gru, audio, eng_notation, blks2, optfir > > class app_top_block(gr.top_block): > def __init__(self): > gr.top_block.__init__(self, "mhp") > > self.source = gr.sig_source_f(48000, gr.GR_TRI_WAVE, 1.0, 1.0, 0) > self.amp = gr.multiply_const_ff(65.0) > self.sink = gr.null_sink(gr.sizeof_float) > > self.connect(self.source, self.amp, self.sink) > self.amp_connected = True > > def shuffle(self): > self.lock() > if self.amp_connected: > self.disconnect(self.source, self.amp, self.sink) > self.connect(self.source, self.sink) > else: > self.disconnect(self.source, self.sink) > self.connect(self.source, self.amp, self.sink) > self.amp_connected = not self.amp_connected > self.unlock() > > if __name__ == "__main__": > tb = app_top_block() > tb.start() > while True: > time.sleep(0.1) > tb.shuffle() > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
