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<div><div>Did you add an extra > character for your response? It is messing with</div><div>my email client, which interprets these as "reply" nesting...</div></div><div><span style="font-family: 微软雅黑, Tahoma; line-height: normal;"><br></span></div><div><span></span><span style="font-family: 微软雅黑, Tahoma; line-height: normal;">> sorry , i will add an extra > character for my response on later reply. </span></div><div><span style="font-family: 微软雅黑, Tahoma; line-height: normal;">>i have know what you said ,thank you very much </span></div>
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<div><span><div style="MARGIN: 10px; FONT-FAMILY: verdana; FONT-SIZE: 10pt"><div>bin.wang@qkmtech.com</div></div></span></div>
<blockquote style="margin-top: 0px; margin-bottom: 0px; margin-left: 0.5em;"><div> </div><div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm"><div style="PADDING-RIGHT: 8px; PADDING-LEFT: 8px; FONT-SIZE: 12px;FONT-FAMILY:tahoma;COLOR:#000000; BACKGROUND: #efefef; PADDING-BOTTOM: 8px; PADDING-TOP: 8px"><div><b>From:</b> <a href="mailto:gedare@rtems.org">Gedare Bloom</a></div><div><b>Date:</b> 2018-01-11 23:09</div><div><b>To:</b> <a href="mailto:bin.wang@qkmtech.com">bin.wang@qkmtech.com</a></div><div><b>CC:</b> <a href="mailto:chrisj@rtems.org">Chris Johns</a>; <a href="mailto:users@rtems.org">Users</a></div><div><b>Subject:</b> Re: Re: smp support</div></div></div><div><div>On Wed, Jan 10, 2018 at 8:48 PM, bin.wang@qkmtech.com</div>
<div><bin.wang@qkmtech.com> wrote:</div>
<div>></div>
<div>>> another question:</div>
<div>>></div>
<div>>> if i use the smp configuration macro define，am i still need to do the</div>
<div>>> mutiprocessor configuration macro define for confdef.h ?</div>
<div>>></div>
<div>> With SMP you have to enable SMP when you configure/build RTEMS, and</div>
<div>> you need to provide the CPP configuration macros to set up the SMP</div>
<div>> system and schedulers.</div>
<div>></div>
<div>>>> what the CPP means?</div>
<div>C Preprocessor.</div>
<div> </div>
<div>Did you add an extra > character for your response? It is messing with</div>
<div>my email client, which interprets these as "reply" nesting...</div>
<div> </div>
<div>>>>in CONFIGURING A SYSTEM chapter in c user doc, i find the two</div>
<div>>>> configurations items . one is 24.22 SMP Specific Configuration Parameters</div>
<div>>>> ,another is 24.24 Multiprocessing Configuration</div>
<div>>>>what i want to ask is if i want to use smp, do i need use the</div>
<div>>>> Multiprocessing Configuration? or i just need use SMP Specific</div>
<div>>>> Configuration Parameters and do not need care about >>the Multiprocessing</div>
<div>>>> Configuration.</div>
<div> </div>
<div>You do not need to care about Multiprocessing Configuration.</div>
<div> </div>
<div>></div>
<div>> "SMP means all cores are treated equally by the operating system."</div>
<div>> "AMP means cores are not treated the same by the OS, which can cover a lot</div>
<div>> of heterogeneous behavior."</div>
<div>>>>i know what you said</div>
<div>>>>so the basic problem which confused me is the difference betweent</div>
<div>>>> Multiprocessing Configuration and SMP Configuration, not the concept of amp</div>
<div>>>> and smp</div>
<div>>>>in my point of view ,no matter AMP or SMP is all called Multiprocessing</div>
<div>>>> because they all use the muticore .is it right ? so if i want to use AMP</div>
<div>>>> mode ,than i need >>just Multiprocessing Configuration?</div>
<div> </div>
<div>There is not support for AMP out of the box with RTEMS as far as I</div>
<div>know. This "Multiprocessing Configuration" stuff is about how to run a</div>
<div>distributed system of multiple RTEMS images, one on each processor,</div>
<div>that share a global object namespace. It is not the same as how to run</div>
<div>a single RTEMS image that manages multiple processors.</div>
<div> </div>
<div>>>>if i want to use SMP mode,than i need Multiprocessing Configuration and</div>
<div>>>> SMP Configuration ?</div>
<div>></div>
<div>></div>
<div>></div>
<div>></div>
<div>></div>
<div>> ________________________________</div>
<div>> bin.wang@qkmtech.com</div>
<div>></div>
<div>></div>
<div>> From: Gedare Bloom</div>
<div>> Date: 2018-01-11 00:43</div>
<div>> To: bin.wang@qkmtech.com</div>
<div>> CC: Chris Johns; Users</div>
<div>> Subject: Re: Re: smp support</div>
<div>> On Fri, Dec 29, 2017 at 3:55 AM, bin.wang@qkmtech.com</div>
<div>> <bin.wang@qkmtech.com> wrote:</div>
<div>>> thanks</div>
<div>>></div>
<div>>> but i still confused about the smp configuration and the mutiprocessor</div>
<div>>> configuration .</div>
<div>>></div>
<div>>> for example. for zynq ,they has two arm core. if i use the mutiprocessor</div>
<div>>> configuration ， Is rtems use the two cores in amp mode ? is the rtems</div>
<div>>> manage the two cores？ if rtems manages two cores，i think it is in smp mode</div>
<div>>> because i think the concept of smp mode is the one system can manage</div>
<div>>> muticores which are same cpu architecture。this is conflictive for my</div>
<div>>> point</div>
<div>>> of view</div>
<div>>></div>
<div>> SMP means all cores are treated equally by the operating system.</div>
<div>></div>
<div>> AMP means cores are not treated the same by the OS, which can cover a</div>
<div>> lot of heterogeneous behavior.</div>
<div>></div>
<div>> RTEMS provides SMP capability.</div>
<div>></div>
<div>>> i think amp mode is rtems run in one core, another core is bare-metal or</div>
<div>>> linux. but the mutiprocessor configuration let me confused, it said as</div>
<div>>> follows</div>
<div>>></div>
<div>>> "The RTEMS multiprocessor execution model is multiple instruction streams</div>
<div>>> with multiple data</div>
<div>>> streams (MIMD). This execution model has each of the processors executing</div>
<div>>> code independent</div>
<div>>> of the other processors. Because of this parallelism, the application</div>
<div>>> designer can more easily</div>
<div>>> guarantee deterministic behavior."</div>
<div>>></div>
<div>> This statement is true regardless of SMP/AMP: in either case, program</div>
<div>> code runs independent of other processors.</div>
<div>></div>
<div>>> is it means one rtems system instance run in one core ,and another rtems</div>
<div>>> system instance run in another core? and they can excute code</div>
<div>>> independent?</div>
<div>>> sorry, i think maybe i have some concept confused</div>
<div>>></div>
<div>> One RTEMS instances executes across both cores, and both cores can</div>
<div>> execute code independent. It is possible for both cores to be</div>
<div>> executing OS functions simultaneously, or one core to execute OS code</div>
<div>> while another runs application, or both cores to execute application</div>
<div>> code in parallel.</div>
<div>></div>
<div>>> if just one rtems run in two core , how to put code into different core to</div>
<div>>> run ? how to realize the parrallelism?</div>
<div>>></div>
<div>> If you select RTEMS with SMP and provide scheduler with two cores, the</div>
<div>> scheduler will assign tasks/threads to the cores according to its</div>
<div>> scheduler policy/algorithm.</div>
<div>></div>
<div>>> another question:</div>
<div>>></div>
<div>>> if i use the smp configuration macro define，am i still need to do the</div>
<div>>> mutiprocessor configuration macro define for confdef.h ?</div>
<div>>></div>
<div>> With SMP you have to enable SMP when you configure/build RTEMS, and</div>
<div>> you need to provide the CPP configuration macros to set up the SMP</div>
<div>> system and schedulers.</div>
<div>></div>
<div>>> ________________________________</div>
<div>>> bin.wang@qkmtech.com</div>
<div>>></div>
<div>>></div>
<div>>> From: Chris Johns</div>
<div>>> Date: 2017-12-29 14:21</div>
<div>>> To: bin.wang@qkmtech.com; Users</div>
<div>>> Subject: Re: smp support</div>
<div>>> On 29/12/17 12:16 pm, bin.wang@qkmtech.com wrote:</div>
<div>>>> thanks a lot .</div>
<div>>>></div>
<div>>>> i have another question , if i use the smp, can i use the interrupt of</div>
<div>>>> rtems?</div>
<div>>>> which i want to interrupt period of hard real time of 125us.</div>
<div>>>></div>
<div>>></div>
<div>>> Yes you can.</div>
<div>>></div>
<div>>>> i do not know the difference of the bare-metal interrupt and the rtems</div>
<div>>>> interrupt</div>
<div>>>> . is the rtems interrupt have performance loss of the hard real-time?</div>
<div>>></div>
<div>>> The interrupt overhead will have the same overhead each time and its</div>
<div>>> deterministic behaviour will depend on the other interrupts in your system</div>
<div>>> and</div>
<div>>> their priority. The performance will depend on what you need to do in the</div>
<div>>> interrupt.</div>
<div>>></div>
<div>>>></div>
<div>>>> what the schedule method of smp use? is it can affect the interrupt</div>
<div>>>> performance?</div>
<div>>>></div>
<div>>></div>
<div>>> That depends on your application.</div>
<div>>></div>
<div>>> Chris</div>
<div>>></div>
<div>>></div>
<div>>> _______________________________________________</div>
<div>>> users mailing list</div>
<div>>> users@rtems.org</div>
<div>>> http://lists.rtems.org/mailman/listinfo/users</div>
<div>></div>
<div> </div>
</div></blockquote>
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