<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p.msonormal0, li.msonormal0, div.msonormal0
{mso-style-name:msonormal;
mso-margin-top-alt:auto;
margin-right:0cm;
mso-margin-bottom-alt:auto;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri",sans-serif;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 2.0cm 70.85pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal">Hello Lang,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">This function is exactly what I was looking for! Thank you a lot!<o:p></o:p></p>
<p class="MsoNormal">But this function would still be called for each module I add to a JIT-Process? Seems like I have to use the LLVM-Link code first to link all the modules to one big.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">That still helped me a lot! Thank you so much!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Kind greetings<o:p></o:p></p>
<p class="MsoNormal">Björn<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b>From:</b> Lang Hames <lhames@gmail.com> <br>
<b>Sent:</b> Montag, 12. November 2018 16:42<br>
<b>To:</b> David Blaikie <dblaikie@gmail.com><br>
<b>Cc:</b> Gaier, Bjoern <Bjoern.Gaier@horiba.com>; LLVM Developers Mailing List <llvm-dev@lists.llvm.org><br>
<b>Subject:</b> Re: [llvm-dev] JIT-Client for Shared Memory<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<div>
<div>
<p class="MsoNormal">Hi Bjoern,<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">For single object files you can override the needsToReserveAllocationSpace method that is inherited from llvm::RuntimeDyld::MemoryManager (make it return true) and then implement the reserveAllocationSpace method to allocate memory for
all sections up front.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">There is no easy way to do this for multiple object files. I think you would have to mimic the memory size calculations performed by RuntimeDyld, then pre-allocate the memory yourself.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal">BUT... There is one problem. The shared memory can't be dynamical adjusted. So if I add another module to the current module, then I would go through this process again! Not the "finalizeMemory" process though, but I would allocate another
shared memory. This is not what I want! Currently I use the linker first, to work around this problem, but this will not help me if I add object files or libraries to the JIT process - or does it?<o:p></o:p></p>
</blockquote>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Unless all of your code is pre-compiled (i.e. you can calculate the required allocations up-front) I do not think this can be avoided. I think the best you can do is conservatively over-allocate shared memory in the hope that you do not
end up needing to make a second allocation.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Cheers,<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal">Lang.<o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal">On Wed, Nov 7, 2018 at 11:12 PM David Blaikie <<a href="mailto:dblaikie@gmail.com">dblaikie@gmail.com</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal" style="margin-bottom:12.0pt">And then I used reply instead of reply-all... I'm on a roll. Added llvm-dev back again... So maybe this is right now. Maybe - sorry for the confusion <o:p></o:p></p>
<div>
<div>
<p class="MsoNormal">On Wed, Nov 7, 2018, 11:11 PM David Blaikie <<a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<p class="MsoNormal" style="margin-bottom:12.0pt">Well I meant to add him but failed. Cc'd him here now :)<o:p></o:p></p>
<div>
<div>
<p class="MsoNormal">On Wed, Nov 7, 2018, 10:41 PM Gaier, Bjoern <<a href="mailto:Bjoern.Gaier@horiba.com" target="_blank">Bjoern.Gaier@horiba.com</a> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm">
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Is… Lang now added? I’m not sure about this system…<br>
<br>
My problem is that I can not change the size of the shared memory I’m targeting – so I can only allocate it once, but how do I know how much memory I’m going to need, when each sections requests the memory after each other?<br>
To work around this I first allocate the memory locally and count the bytes it needed. After notifyObjectLoaded I can request the shared memory and do the mapping. But this only covers one module. If I have two modules for example, then I will end up having
two shared memories, because the second module will go through the same steps as the first one. But I want to have one coherent memory.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Also the applying of the mapping causes a bug with the new LLVM7 – I already filled out a bug report for this. But I have no idea how things will progress from that point… Still
I have no idea about the system…<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"><b>From:</b> David Blaikie <<a href="mailto:dblaikie@gmail.com" target="_blank">dblaikie@gmail.com</a>>
<br>
<b>Sent:</b> Mittwoch, 7. November 2018 17:34<br>
<b>To:</b> Gaier, Bjoern <<a href="mailto:Bjoern.Gaier@horiba.com" target="_blank">Bjoern.Gaier@horiba.com</a>><br>
<b>Cc:</b> llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>><br>
<b>Subject:</b> Re: [llvm-dev] JIT-Client for Shared Memory<o:p></o:p></p>
</div>
</div>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;margin-bottom:12.0pt">Adding Lang here in case he's got some insight.<br>
<br>
I take it the system you're targeting doesn't have the memory limitations that some systems have, where once memory is set executable, it can never be written to? & so you'd like to write some code into a page, execute it, write some more code into the same
page and have that execute too?<br>
<br>
(I don't know teh JIT architecture well enough to know if that's supported, or if I'm accurately understanding your situation, etc)<o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">On Thu, Nov 1, 2018 at 11:49 PM Gaier, Bjoern via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
</div>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt">
<div>
<div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Hello everyone,<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I want to use the LLVM to write a JIT client, that works with shared memory. Currently I proceed as following:<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">I wrote an own class that inherits "<i>RTDyldMemoryManager</i>". The functions "<i>allocateCodeSection</i>" and "<i>allocateDataSection</i>" are allocating local non-shared memory.
I store there addresses in a std::vector.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">When the function "<i>notifyObjectLoaded</i>" is invoked, I allocate the shared memory - I'm getting the size from the local non-shared memory - and apply the address mapping.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">When the function "<i>finalizeMemory</i>" is invoked I copy the code from the local non-shared memory to the shared memory but only one time.
<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">So far so good, this works actually good! Yippie x3<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">BUT... There is one problem. The shared memory can't be dynamical adjusted. So if I add another module to the current module, then I would go through this process again! Not the
"<i>finalizeMemory</i>" process though, but I would allocate another shared memory. This is not what I want! Currently I use the linker first, to work around this problem, but this will not help me if I add object files or libraries to the JIT process - or
does it?<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">So is there any way to work around this?<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto"> <o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Kind greetings<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Björn<o:p></o:p></p>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert,
Takashi Nagano, Takeshi Fukushima. Junichi Tajika <o:p></o:p></p>
</div>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><o:p></o:p></p>
</blockquote>
</div>
</div>
</div>
<p class="MsoNormal">Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Takeshi Fukushima. Junichi Tajika
<o:p></o:p></p>
</div>
</blockquote>
</div>
</blockquote>
</div>
</blockquote>
</div>
</div>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Takeshi Fukushima. Junichi Tajika
</body>
</html>