Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCH] ARC: Enable machine_desc->init_per_cpu for non-SMP
 configs
To:     Alexey Brodkin <Alexey.Brodkin@synopsys.com>
CC:     "wbx@uclibc-ng.org" <wbx@uclibc-ng.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-snps-arc@lists.infradead.org" 
        <linux-snps-arc@lists.infradead.org>
References: <20171129082145.23327-1-abrodkin@synopsys.com>
 <ee663800-7f72-c310-2a65-d8b52a811f15@synopsys.com>
 <59f6fc647175e3f22f530fc4497cc4104af355e7.camel@synopsys.com>
From:   Vineet Gupta <Vineet.Gupta1@synopsys.com>
Openpgp: preference=signencrypt
Autocrypt: addr=vgupta@synopsys.com; keydata=
 xsFNBFEffBMBEADIXSn0fEQcM8GPYFZyvBrY8456hGplRnLLFimPi/BBGFA24IR+B/Vh/EFk
 B5LAyKuPEEbR3WSVB1x7TovwEErPWKmhHFbyugdCKDv7qWVj7pOB+vqycTG3i16eixB69row
 lDkZ2RQyy1i/wOtHt8Kr69V9aMOIVIlBNjx5vNOjxfOLux3C0SRl1veA8sdkoSACY3McOqJ8
 zR8q1mZDRHCfz+aNxgmVIVFN2JY29zBNOeCzNL1b6ndjU73whH/1hd9YMx2Sp149T8MBpkuQ
 cFYUPYm8Mn0dQ5PHAide+D3iKCHMupX0ux1Y6g7Ym9jhVtxq3OdUI5I5vsED7NgV9c8++baM
 7j7ext5v0l8UeulHfj4LglTaJIvwbUrCGgtyS9haKlUHbmey/af1j0sTrGxZs1ky1cTX7yeF
 nSYs12GRiVZkh/Pf3nRLkjV+kH++ZtR1GZLqwamiYZhAHjo1Vzyl50JT9EuX07/XTyq/Bx6E
 dcJWr79ZphJ+mR2HrMdvZo3VSpXEgjROpYlD4GKUApFxW6RrZkvMzuR2bqi48FThXKhFXJBd
 JiTfiO8tpXaHg/yh/V9vNQqdu7KmZIuZ0EdeZHoXe+8lxoNyQPcPSj7LcmE6gONJR8ZqAzyk
 F5voeRIy005ZmJJ3VOH3Gw6Gz49LVy7Kz72yo1IPHZJNpSV5xwARAQABzS1WaW5lZXQgR3Vw
 dGEgKHBlcnNvbmFsKSA8dmluZWV0Zzc2QGdtYWlsLmNvbT7CwX4EEwECACgCGwMGCwkIBwMC
 BhUIAgkKCwQWAgMBAh4BAheABQJbBYpwBQkLx0HcAAoJEGnX8d3iisJe9TAP/3ljkSlRwToH
 O0E9QimJJqF52uZ0phSg1ZoavgHhGtz1mRykgeOzOITpFmYGBnf3v2Z33fDltIxTaN5TkRwl
 DjYvz1NTBlTLyPRbYwdCn6YyVSWj75hiGwdD0/N5M7Rb3XYsyDHvZ/tns1oGwipPmu9G+JoB
 VOkZw/bviE8AmGEK54PWdU1t3AnJ/3wtT6FSIPlTtCREiuZdQItjFkH0sYL1/BOXcE+XoBoQ
 9hx6IEb46pop9ix/IRov2y6ZBUtDbF+SOSvImRadvD8A1ttvH51naP21Bra3ypV/GmZOR1/U
 8azvgKmimYvC0345za/dS8eqrDuSh2IbEkDR0juQsFbkWS4IY5uqckzRWxHVZBas9CjpjipO
 C4iTzxq3CgmCyAD5qlQndJdhbsTgN18PXVAAI/phC1BtjNOoCgWgNsr8JK2TbXNF9wSR17T7
 jDWCZ+Up8k5CTVQywLwJl91u5dV82WAnHnv3U1dwUX46DFMenV16ADfRrm7ib+D/O0XZMP7B
 sGC7PPleU+Ej/rt6V4H6VZ5RC9CXVCdUjM+ZZsqJc6/f5od4gSyswWQzCb/izU5ebxrehTUJ
 lPh2QCa6e46G1WzLWwZCFmQU3uUQtCXU1BBId/nL+Y3hQW0XKapvTx+zr8cZAZDXb83YE8Qs
 inBoGE5y9nj+ZveaVZHZRy63zsFNBFEffBMBEADXZ2pWw4Regpfw+V+Vr6tvZFRl245PV9rW
 FU72xNuvZKq/WE3xMu+ZE7l2JKpSjrEoeOHejtT0cILeQ/Yhf2t2xAlrBLlGOMmMYKK/K0Dc
 2zf0MiPRbW/NCivMbGRZdhAAMx1bpVhInKjU/6/4mT7gcE57Ep0tl3HBfpxCK8RRlZc3v8BH
 OaEfcWSQD7QNTZK/kYJo+Oyux+fzyM5TTuKAaVE63NHCgWtFglH2vt2IyJ1XoPkAMueLXay6
 enSKNci7qAG2UwicyVDCK9AtEub+ps8NakkeqdSkDRp5tQldJbfDaMXuWxJuPjfSojHIAbFq
 P6QaANXvTCSuBgkmGZ58skeNopasrJA4z7OsKRUBvAnharU82HGemtIa4Z83zotOGNdaBBOH
 NN2MHyfGLm+kEoccQheH+my8GtbH1a8eRBtxlk4c02ONkq1Vg1EbIzvgi4a56SrENFx4+4sZ
 cm8oItShAoKGIE/UCkj/jPlWqOcM/QIqJ2bR8hjBny83ONRf2O9nJuEYw9vZAPFViPwWG8tZ
 7J+ReuXKai4DDr+8oFOi/40mIDe/Bat3ftyd+94Z1RxDCngd3Q85bw13t2ttNLw5eHufLIpo
 EyAhTCLNQ58eT91YGVGvFs39IuH0b8ovVvdkKGInCT59Vr0MtfgcsqpDxWQXJXYZYTFHd3/R
 swARAQABwsFlBBgBAgAPAhsMBQJbBYpwBQkLx0HdAAoJEGnX8d3iisJewe8P/36pkZrVTfO+
 U+Gl1OQh4m6weozuI8Y98/DHLMxEujKAmRzy+zMHYlIl3WgSih1UMOZ7U84yVZQwXQkLItcw
 XoihChKD5D2BKnZYEOLM+7f9DuJuWhXpee80aNPzEaubBYQ7dYt8rcmB7SdRz/yZq3lALOrF
 /zb6SRleBh0DiBLP/jKUV74UAYV3OYEDHN9blvhWUEFFE0Z+j96M4/kuRdxvbDmp04Nfx79A
 mJEnfv1Vvc9CFiWVbBrNPKomIN+JV7a7m2lhbfhlLpUk0zGFDTWcWejl4qz/pCYSoIUU4r/V
 BsCVZrOun4vd4cSi/yYJRY4kaAJGCL5k7qhflL2tgldUs+wERH8ZCzimWVDBzHTBojz0Ff3w
 2+gY6FUbAJBrBZANkymPpdAB/lTsl8D2ZRWyy90f4VVc8LB/QIWY/GiS2towRXQBjHOfkUB1
 JiEXYH/i93k71mCaKfzKGXTVxObU2I441w7r4vtNlu0sADRHCMUqHmkpkjV1YbnYPvBPFrDB
 S1V9OfD9SutXeDjJYe3N+WaLRp3T3x7fYVnkfjQIjDSOdyPWlTzqQv0I3YlUk7KjFrh1rxtr
 poYSIQKf5HuMowUNtjyiK2VhA5V2XDqd+ZUT3RqfAPf3Y5HjkhKJRqoIDggUKMUKmXaxCkPG
 i91ThhqBJlyU6MVUa6vZNv8E
Message-ID: <eb9111fb-7530-98d9-6800-8413ad90360c@synopsys.com>
Date:   Wed, 20 Jun 2018 16:11:27 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.8.0
MIME-Version: 1.0
In-Reply-To: <59f6fc647175e3f22f530fc4497cc4104af355e7.camel@synopsys.com>
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 06/14/2018 03:26 PM, Alexey Brodkin wrote:
> Hi Vineet,
>
> On Thu, 2017-11-30 at 09:46 -0800, Vineet Gupta wrote:
>> On 11/29/2017 12:21 AM, Alexey Brodkin wrote:
>>> As of today we assumed that "machine_desc->init_per_cpu" calls
>>> are only usable on SMP systems when we want to run some piece of
>>> code on early boot for each and every core, I guess assumption was
>>> we have "machine_desc->init_early" for single-core cases where
>>> the one and only master core can do all the things.
>>>
>>> But it turned out for platforms which might be both UP and SMP it
>>> might be benificial to use "init_per_cpu" for both UP and SMP cases
>>> with which we achieve 2 things simultaneously:
>>>   1) Exactly the same one code will be used for UP&SMP for
>>>      things required to be done on each an every core regardless if it's
>>>      a master and the only core in UP system or any other slave core in SMP
>>>      setup.
>>>   1) There will be no "ifdef CONFIG_SMP" around "init_per_cpu".
>>>
>> Seems fine to me. However this needs to go with the actual platform change which 
>> needs it.
> Well for example this might get in the way of building kernel for HSDK with
> CONFIG_SMP disabled which is IMHO quite valid case in terms of testing
> code-base compiled with no CONFIG_SMP 

Fair enough - although world is moving away from UP.


> (something Waldemar was up to).

Really, why does he care if we are running SMP kernel - oh his simulation time
goes up. But honestly he should try and use the SMP kernel for testing as that
might uncover any system wide / SMP specific bugs in testing uclibc as well !

> Is it a strong enough reason for that patch to be applied?

Well per my original reply I didn't have any objections for this per-se and wanted
to see the platform patch. Seems we don't need platform patch as it is not under
#ifdef in hsdk/platform.c

I'll queue this up !

-Vineet