<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><a href="https://en.wikipedia.org/wiki/Bus_error" class="">https://en.wikipedia.org/wiki/Bus_error</a><div class=""><br class=""></div><div class="">But perhaps not true for Intel? </div><div class=""><br class=""></div><div class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Aug 24, 2020, at 1:06 PM, Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class=""><div dir="ltr" class="">On Mon, Aug 24, 2020 at 1:46 PM Barry Smith <<a href="mailto:bsmith@petsc.dev" class="">bsmith@petsc.dev</a>> wrote:<br class=""></div><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br class="">
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> On Aug 24, 2020, at 12:39 PM, Jed Brown <<a href="mailto:jed@jedbrown.org" target="_blank" class="">jed@jedbrown.org</a>> wrote:<br class="">
> <br class="">
> Barry Smith <<a href="mailto:bsmith@petsc.dev" target="_blank" class="">bsmith@petsc.dev</a>> writes:<br class="">
> <br class="">
>>> On Aug 24, 2020, at 12:31 PM, Jed Brown <<a href="mailto:jed@jedbrown.org" target="_blank" class="">jed@jedbrown.org</a>> wrote:<br class="">
>>> <br class="">
>>> Barry Smith <<a href="mailto:bsmith@petsc.dev" target="_blank" class="">bsmith@petsc.dev</a>> writes:<br class="">
>>> <br class="">
>>>> So if a BLAS errors with SIGBUS then it is always an input error of just not proper double/complex alignment? Or some other very strange thing?<br class="">
>>> <br class="">
>>> I would suspect memory corruption.<br class="">
>> <br class="">
>> <br class="">
>> Corruption meaning what specifically?<br class="">
>> <br class="">
>> The routines crashing are dgemv which only take double precision arrays, regardless of what garbage is in those arrays i don't think there can be BUS errors resulting. They don't take integer arrays whose corruption could result in bad indexing and then BUS errors. <br class="">
>> <br class="">
>> So then it can only be corruption of the pointers passed in, correct?<br class="">
> <br class="">
> Such as those pointers pointing into data on the stack with incorrect sizes.<br class="">
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But won't incorrect sizes "usually" lead to SEGV not SEGBUS?<br class="">
</blockquote></div><br clear="all" class=""><div class="">My understanding was that roughly memory errors in the heap are SEGV and memory errors on the stack are SIGBUS. Is that not true?</div><div class=""><br class=""></div><div class=""> Matt</div><div class=""><br class=""></div>-- <br class=""><div dir="ltr" class="gmail_signature"><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class=""><div dir="ltr" class=""><div class="">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br class="">-- Norbert Wiener</div><div class=""><br class=""></div><div class=""><a href="http://www.cse.buffalo.edu/~knepley/" target="_blank" class="">https://www.cse.buffalo.edu/~knepley/</a><br class=""></div></div></div></div></div></div></div></div>
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