RE: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change?
Hello, Even after asking again, I never did hear from the customer why it matters if the name changes. The case is being closed, and I am assuming that the information you gave (that I passed onto the customer) was sufficient to answer the customer's question. Thank you Greg, Vitaly, and Peter for helping answer this question. エアー・アルマ Professional Direct Delivery Manager Email: v-ale...@microsoft.com Microsoft Azure Professional Direct Services 日本 +81 1-2051-4100（無料） 日本 +81 3-6743-9670（有料） 電子メール: pdaz...@microsoft.com -Original Message- From: Greg KH Sent: Friday, June 22, 2018 10:51 PM To: Peter Zijlstra Cc: Alma Eyre (Sonata Software North America) ; Haiyang Zhang ; de...@linuxdriverproject.org; Vitaly Kuznetsov ; Linus Torvalds ; Thomas Gleixner Subject: Re: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change? On Fri, Jun 22, 2018 at 10:22:28AM +0200, Peter Zijlstra wrote: > On Fri, Jun 22, 2018 at 03:17:25AM +, Alma Eyre (Sonata Software North > America) wrote: > > Hello, > > > > This is Alma supporting Azure for Japanese customers. I had a > > question from a customer that I could not find the answers for. I > > saw this > > github(https://na01.safelinks.protection.outlook.com/?url=https%3A%2 > > F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F88c9281a9fba67636ab26c1 > > fd6afbc78a632374f&data=02%7C01%7Cv-aleyre%40microsoft.com%7Cfd2c > > bcc41da54a65be1908d5d8cd635c%7C72f988bf86f141af91ab2d7cd011db47%7C1% > > 7C0%7C636653299021462729&sdata=B0KCAukioytYR0RlTPr2n3KVCrKzkRem2 > > ir1aBiXXoA%3D&reserved=0) page, and I was wondering if someone > > on this list might be able to answer the question. > > > > Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource > > pages change? > > https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu > b.com%2Ftorvalds%2Flinux%2Fblob%2Fe7aa8c2eb11ba69b1b69099c3c7bd6be3087 > b0ba%2FDocumentation%2Fprocess%2Fstable-api-nonsense.rst&data=02%7 > C01%7Cv-aleyre%40microsoft.com%7Cfd2cbcc41da54a65be1908d5d8cd635c%7C72 > f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636653299021462729&sdata= > URuIH1hhfWowC4yfkZxZB8Gg9%2Fo6rEkzufMOUSgjJug%3D&reserved=0 Or better yet, in a pretty html format: https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Flatest%2Fprocess%2Fstable-api-nonsense.html&data=02%7C01%7Cv-aleyre%40microsoft.com%7Cfd2cbcc41da54a65be1908d5d8cd635c%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636653299021462729&sdata=UBkvgJz9XcURXiTPbV1CImpK9DsnbK9HTgFwZCKjcJU%3D&reserved=0 But, this is a name of a clocksource, not really an internal kernel api. Alma, what external tool depends on the specific name of a kernel clock? Why would it matter what the name of it is? thanks, greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
RE: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change?
Thank you everybody for your help. I have passed this information along to the customer and asked for the reason they want to refer to the name of the clocksource. エアー・アルマ Professional Direct Delivery Manager Email: v-ale...@microsoft.com Microsoft Azure Professional Direct Services 日本 +81 1-2051-4100（無料） 日本 +81 3-6743-9670（有料） 電子メール: pdaz...@microsoft.com -Original Message- From: Greg KH Sent: Friday, June 22, 2018 10:51 PM To: Peter Zijlstra Cc: Alma Eyre (Sonata Software North America) ; Haiyang Zhang ; de...@linuxdriverproject.org; Vitaly Kuznetsov ; Linus Torvalds ; Thomas Gleixner Subject: Re: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change? On Fri, Jun 22, 2018 at 10:22:28AM +0200, Peter Zijlstra wrote: > On Fri, Jun 22, 2018 at 03:17:25AM +, Alma Eyre (Sonata Software North > America) wrote: > > Hello, > > > > This is Alma supporting Azure for Japanese customers. I had a > > question from a customer that I could not find the answers for. I > > saw this > > github(https://na01.safelinks.protection.outlook.com/?url=https%3A%2 > > F%2Fgithub.com%2Ftorvalds%2Flinux%2Fcommit%2F88c9281a9fba67636ab26c1 > > fd6afbc78a632374f&data=02%7C01%7Cv-aleyre%40microsoft.com%7Cfd2c > > bcc41da54a65be1908d5d8cd635c%7C72f988bf86f141af91ab2d7cd011db47%7C1% > > 7C0%7C636653299021462729&sdata=B0KCAukioytYR0RlTPr2n3KVCrKzkRem2 > > ir1aBiXXoA%3D&reserved=0) page, and I was wondering if someone > > on this list might be able to answer the question. > > > > Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource > > pages change? > > https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithu > b.com%2Ftorvalds%2Flinux%2Fblob%2Fe7aa8c2eb11ba69b1b69099c3c7bd6be3087 > b0ba%2FDocumentation%2Fprocess%2Fstable-api-nonsense.rst&data=02%7 > C01%7Cv-aleyre%40microsoft.com%7Cfd2cbcc41da54a65be1908d5d8cd635c%7C72 > f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636653299021462729&sdata= > URuIH1hhfWowC4yfkZxZB8Gg9%2Fo6rEkzufMOUSgjJug%3D&reserved=0 Or better yet, in a pretty html format: https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Flatest%2Fprocess%2Fstable-api-nonsense.html&data=02%7C01%7Cv-aleyre%40microsoft.com%7Cfd2cbcc41da54a65be1908d5d8cd635c%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636653299021462729&sdata=UBkvgJz9XcURXiTPbV1CImpK9DsnbK9HTgFwZCKjcJU%3D&reserved=0 But, this is a name of a clocksource, not really an internal kernel api. Alma, what external tool depends on the specific name of a kernel clock? Why would it matter what the name of it is? thanks, greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change?
On Fri, Jun 22, 2018 at 10:22:28AM +0200, Peter Zijlstra wrote: > On Fri, Jun 22, 2018 at 03:17:25AM +, Alma Eyre (Sonata Software North > America) wrote: > > Hello, > > > > This is Alma supporting Azure for Japanese customers. I had a question > > from a customer that I could not find the answers for. I saw this > > github(https://github.com/torvalds/linux/commit/88c9281a9fba67636ab26c1fd6afbc78a632374f) > > page, and I was wondering if someone on this list might be able to > > answer the question. > > > > Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource > > pages change? > > https://github.com/torvalds/linux/blob/e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba/Documentation/process/stable-api-nonsense.rst Or better yet, in a pretty html format: https://www.kernel.org/doc/html/latest/process/stable-api-nonsense.html But, this is a name of a clocksource, not really an internal kernel api. Alma, what external tool depends on the specific name of a kernel clock? Why would it matter what the name of it is? thanks, greg k-h ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change?
"Alma Eyre (Sonata Software North America)" writes: > Hello, > > This is Alma supporting Azure for Japanese customers. I had a question from a > customer that I could not find the answers for. I saw this > github(https://github.com/torvalds/linux/commit/88c9281a9fba67636ab26c1fd6afbc78a632374f) > page, and I was > wondering if someone on this list might be able to answer the question. > > Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages > change? > > Background: > > The customer is experiencing "tsc: Fast TSC calibration failed" error > on their CentOS 7.4（3.10.0-693.11.6.el7) VM. Hi Alma, I think the following upstream commit would help: commit 71c2a2d0a81f096a2932fccb39a500116fece554 Author: Vitaly Kuznetsov Date: Thu Jun 22 18:07:30 2017 +0800 x86/hyperv: Read TSC frequency from a synthetic MSR > > My research: > > Although I could find information that both of these pages are maintained by > Microsoft, I could not find any information about whether these pages are > subject to name change. > > Regarding both > > Here(https://github.com/torvalds/linux/commit/88c9281a9fba67636ab26c1fd6afbc78a632374f) > it says "On Hyper-V platform there > > are two good clocksources: MSR-based hyperv_clocksource and > > recently introduced TSC page." > > Regarding hyperv_clocksource_tsc_page > > The mechanism is detailed > here(https://opensource.com/article/17/6/timekeeping-linux-vms) but whether > or not this page will ever change names is not noted. It also says "Microsoft > reinvented the pv_clock protocol with their own TSC page proctol, " > > Here(https://lists.linuxfoundation.org/pipermail/virtualization/2017-February/034235.html) > it says that the TSC page is documented, but I cannot find the documentation. > TSC page clocksource is documented in TLFS: https://github.com/Microsoft/Virtualization-Documentation/raw/master/tlfs/Hypervisor%20Top%20Level%20Functional%20Specification%20v5.0b.pdf (12.6.2 Format of the Reference TSC Page) But to be honest I didn't get your question. In case you're asking if 'hyperv_clocksource_tsc_page' name is stable than the answer is: there is no guarantee. Nobody will probably change the name just for the sake of change but it can be changed for a reason. -- Vitaly ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
Re: Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource pages change?
On Fri, Jun 22, 2018 at 03:17:25AM +, Alma Eyre (Sonata Software North America) wrote: > Hello, > > This is Alma supporting Azure for Japanese customers. I had a question > from a customer that I could not find the answers for. I saw this > github(https://github.com/torvalds/linux/commit/88c9281a9fba67636ab26c1fd6afbc78a632374f) > page, and I was wondering if someone on this list might be able to > answer the question. > > Will the name of hyperv_clocksource_tsc_page or hyperv_clocksource > pages change? https://github.com/torvalds/linux/blob/e7aa8c2eb11ba69b1b69099c3c7bd6be3087b0ba/Documentation/process/stable-api-nonsense.rst ___ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
