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Per container uptime?
by François April 13, 2017

April 13, 2017

Hi, after reading that post [1] on serverfault, I was wondering whether it would make sense to implement a per container uptime. Do you think it makes sense at all? Any hint on how to get started on that? Thanks François [1] http://serverfault.com/questions/830643/uptime-command-gives-weird-results-…

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Re: How to browse the code
by manty kuma April 13, 2017

April 13, 2017

Here you can see where sk_buff structure is delared. http://androidxref.com/kernel_3.18/xref/include/linux/skbuff.h#506 May be you want to get familiar on how to use opengroks interface by seeing some youtube video or some online documents... Whatever you want to do wrt to source code browsing, this can do it for you very quickly. On Thu, Apr 13, 2017 at 6:24 AM, Code Soldier1 <codesoldier1(a)gmail.com> wrote: > Thanks a lot. I am still not able to lookup structures, such as > sk_buff and where does it's fields get set/used. > > On Tue, Apr 11, 2017 at 4:56 PM, manty kuma <mantykuma(a)gmail.com> wrote: > > I like Opengrok. It is insanely fast in giving search results. However it > > takes sometime to setup and you need to index it before the first use. > > > > If you are ok with browsing someold kernels, then you can use this link > > http://androidxref.com/kernel_3.18/ which is maintained privately. > > > > If you want to use opengrok on more recent linux releases, you may have > to > > set it up yourself. > > > > On Wed, Apr 12, 2017 at 5:13 AM, Mandeep Sandhu > > <mandeepsandhu.chd(a)gmail.com> wrote: > >>> > >>> > >>> I am looking for something that can list all the places that a certain > >>> field of a certain structure is used. For example, sk_buff has a field > >>> called destructor, but so do many other data structures. How do I > >>> search for places where just the destructor field of sk_buff. > >> > >> > >> I think lxr has an identifier & free-text search (powered by google). If > >> that doesn't do it for you, you can go "old school" and try cscope > maybe? > >> > >> HTH, > >> -mandeep > >> > >> > >>> > >>> > >>> Thanks a lot. > >>> > >>> -- > >>> CS1 > >>> > >>> _______________________________________________ > >>> Kernelnewbies mailing list > >>> Kernelnewbies(a)kernelnewbies.org > >>> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > >> > >> > >> > >> _______________________________________________ > >> Kernelnewbies mailing list > >> Kernelnewbies(a)kernelnewbies.org > >> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > >> > > > > > > -- > CS1 >

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USB shutdown issue
by manty kuma April 13, 2017

April 13, 2017

Hi, I have a USB modem connected to my Edison based board. *The USB Modem is frequently disconnected and comes back again in sometime.* Here are the corresponding logs --------------------------------------------------------------------------------------------------------- [ 2054.590012] *hub 1-0:1.0: port 1 disabled by hub (EMI?), re-enabling...* [ 2054.590129] usb 1-1: USB disconnect, device number 3 [ 2054.590610] cdc_ether 1-1:1.0 enp0s17u1: unregister 'cdc_ether' usb-dwc3-host.2-1, CDC Ethernet Device [ 2062.368706] usb 1-1: new high-speed USB device number 4 using dwc3-host [ 2062.393589] usb 1-1: New USB device found, idVendor=12d1, idProduct=1f01 [ 2062.393621] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 2062.393642] usb 1-1: Product: HUAWEI Mobile [ 2062.393661] usb 1-1: Manufacturer: HUAWEI .... [ 2063.629109] cdc_ether 1-1:1.0 eth0: register 'cdc_ether' at usb-dwc3-host.2-1, CDC Ethernet Device, 00:1e:10:1f:00:00 --------------------------------------------------------------------------------------------------------- As i understand this log, due to some reason, the USB hub port 1 is shutdown. Detecting this, the USB hub driver is re-enabling the port. I would like to know why exactky the USB hub's port is shutfown. In short I am trying to find out the reason for this message - "port 1 disabled by hub (EMI?), re-enabling..." The source code that is doing this is here - http://androidxref.com/kernel_3.10/xref/drivers/usb/core/hub.c#4693 But I did not get much info from here. Someone who is proficient with USB protocol might be able to asnwer this very quickly. Looking forward for response. My env : Platform Intel Edison Linux : 3.10 built using Yocto. root@edison:~# uname -a Linux edison 3.10.98-poky-edison+ #2 SMP PREEMPT Wed Feb 22 11:23:11 JST 2017 i686 GNU/Linux Best Regards, Manty

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How to browse the code
by Code Soldier1 April 13, 2017

April 13, 2017

Folks, Can you tell me how to effectively browse linux kernel code. I am familiar with lxr etc but they do not do what I want or atleast I do not know how to. I am looking for something that can list all the places that a certain field of a certain structure is used. For example, sk_buff has a field called destructor, but so do many other data structures. How do I search for places where just the destructor field of sk_buff. Thanks a lot. -- CS1

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Re: How to browse the code
by Mandeep Sandhu April 12, 2017

April 12, 2017

On Wed, Apr 12, 2017 at 2:46 PM, Mandeep Sandhu <mandeepsandhu.chd(a)gmail.com > wrote: > On Wed, Apr 12, 2017 at 2:41 PM, Code Soldier1 <codesoldier1(a)gmail.com> > wrote: > >> Yes that is possible but it is very time consuming. Let's say I get >> 500 hits ? Try searching for destructor in linux kernel code. I am >> only interested in the one that is defined in sk_buff. >> > > Look at cscope & ctags for such queries. Both tools will list all > instances where the said identifier is declared. If a field is defined in > multiple structs, you will get multiple results from which you have to sift > through (it will still be less than free-text search that you'd do on lxr > though). > > Also, please reply to the list (and not to me directly). Others on this > list might have better suggestions. > (and I myself forgot to CC the list! :P) -mandeep > HTH, > -mandeep > > > >> >> On Wed, Apr 12, 2017 at 2:28 PM, Mandeep Sandhu >> <mandeepsandhu.chd(a)gmail.com> wrote: >> > On Wed, Apr 12, 2017 at 2:25 PM, Code Soldier1 <codesoldier1(a)gmail.com> >> > wrote: >> >> >> >> Thanks. This does not completely solve my issue. I am looking for >> >> something that can associate a field name with the structure. >> > >> > >> > Well, you can search for a field's use using free-text search, then >> looks at >> > the line of code to figure out what struct it's part of, no? :) >> > >> > -mandeep >> > >> > >> >> >> >> >> >> On Tue, Apr 11, 2017 at 1:13 PM, Mandeep Sandhu >> >> <mandeepsandhu.chd(a)gmail.com> wrote: >> >> >> >> >> >> I am looking for something that can list all the places that a >> certain >> >> >> field of a certain structure is used. For example, sk_buff has a >> field >> >> >> called destructor, but so do many other data structures. How do I >> >> >> search for places where just the destructor field of sk_buff. >> >> > >> >> > >> >> > I think lxr has an identifier & free-text search (powered by >> google). If >> >> > that doesn't do it for you, you can go "old school" and try cscope >> >> > maybe? >> >> > >> >> > HTH, >> >> > -mandeep >> >> > >> >> > >> >> >> >> >> >> >> >> >> Thanks a lot. >> >> >> >> >> >> -- >> >> >> CS1 >> >> >> >> >> >> _______________________________________________ >> >> >> Kernelnewbies mailing list >> >> >> Kernelnewbies(a)kernelnewbies.org >> >> >> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> >> > >> >> > >> >> >> >> >> >> >> >> -- >> >> CS1 >> > >> > >> >> >> >> -- >> CS1 >> > >

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Re: How to browse the code
by Mandeep Sandhu April 12, 2017

April 12, 2017

On Wed, Apr 12, 2017 at 2:25 PM, Code Soldier1 <codesoldier1(a)gmail.com> wrote: > Thanks. This does not completely solve my issue. I am looking for > something that can associate a field name with the structure. > Well, you can search for a field's use using free-text search, then looks at the line of code to figure out what struct it's part of, no? :) -mandeep > > On Tue, Apr 11, 2017 at 1:13 PM, Mandeep Sandhu > <mandeepsandhu.chd(a)gmail.com> wrote: > >> > >> I am looking for something that can list all the places that a certain > >> field of a certain structure is used. For example, sk_buff has a field > >> called destructor, but so do many other data structures. How do I > >> search for places where just the destructor field of sk_buff. > > > > > > I think lxr has an identifier & free-text search (powered by google). If > > that doesn't do it for you, you can go "old school" and try cscope maybe? > > > > HTH, > > -mandeep > > > > > >> > >> > >> Thanks a lot. > >> > >> -- > >> CS1 > >> > >> _______________________________________________ > >> Kernelnewbies mailing list > >> Kernelnewbies(a)kernelnewbies.org > >> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > > > > > > > -- > CS1 >

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How does GSO works
by Code Soldier1 April 12, 2017

April 12, 2017

Can anyone explain to me how GSO works. I am am trying to understand how segmentation happens. If someone can share a stack trace that would be very helpful.. Thanks -- CS1

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Btrfs Questions for Personal Data Archive
by nick April 11, 2017

April 11, 2017

Greetings All, I am assuming this is coming from me it's just going to get no reply. However if someone who works on btrfs is willing to reply to this I have a few questions. Firstly I have a lot of personal storage for archiving various things probably around ~37TB filled currently in external drives and estimate the archive to grow to around ~300 to 400 TB. All of these numbers are unformatted for people's information. I have been using btrfs but need to ask a few questions for how to create a central archive best: 1.Does the compression algorithms used as according to my knowledge they don't do it well enough to enable it for non text files? What are the performance disadvantages from a IO perspective(I can Google this but I want numbers from someone who works in a data center)? This is primary due to the central archive needing to be used for many different systems at a time. I assume around 3-4 on average maybe more including during a rebuild. Some of it is also hit bit rate encodes I have done for bluray which are around 10-22mbps per second and may need to be watched during a raid rebuild. GPU processing will be client side so don't worry about that. 2. Same as above but for software raid versus hardware raid in btrfs.I am stressing rebuild time here on a raid 5/6. Probably going to use raid 60 as that gives me a mirror plus two drives failure for redundancy. 3. I have found very little information on this but does the metadata being on a SSD actually help with performance? Very little information exist off the wiki for this. I literally goggled for a few hours and found very little even in terms of papers. Further more the archive is going to be on external hard drives for a while, as hard drives are not big enough. If people want more information or have advice on how to scale this out that would be very helpful. Generally I am looking for information related to btrfs. If anyone replies huge thanks, Nick P.S. If anyone tells me to send my questions to the btrfs list I did some stupid things and was banned from vger so I am just sending it here for now.

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Re: Welcome to the "Kernelnewbies" mailing list
by juan pedro meriño April 11, 2017

April 11, 2017

Hi! I have been looking at versions 1,2,3 and 4 of the linux kernel. I would like to know what are the programs for the kernel development environment. To test them and add new features. Thank you very much! On Mon, Apr 10, 2017 at 7:05 PM, <kernelnewbies-request(a)kernelnewbies.org> wrote: > Welcome to the Kernelnewbies(a)kernelnewbies.org mailing list! Welcome > to the kernelnewbies mailing list. Please see > http://lists.kernelnewbies.org/ to change membership info and > preferences. > > To post to this list, send your email to: > > kernelnewbies(a)kernelnewbies.org > > General information about the mailing list is at: > > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > > If you ever want to unsubscribe or change your options (eg, switch to > or from digest mode, change your password, etc.), visit your > subscription page at: > > https://lists.kernelnewbies.org/mailman/options/kernelnewbies/juapdiaz% > 40gmail.com > > > You can also make such adjustments via email by sending a message to: > > Kernelnewbies-request(a)kernelnewbies.org > > with the word `help' in the subject or body (don't include the > quotes), and you will get back a message with instructions. > > You must know your password to change your options (including changing > the password, itself) or to unsubscribe. It is: > > juanpepe > > Normally, Mailman will remind you of your kernelnewbies.org mailing > list passwords once every month, although you can disable this if you > prefer. This reminder will also include instructions on how to > unsubscribe or change your account options. There is also a button on > your options page that will email your current password to you. >

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Question about uprobes
by W. Michael Petullo April 7, 2017

April 7, 2017

I am writing some software that monitors a guest VM using virtual-machine introspection and "hijacks" system calls under certain conditions. For example, the program might inject an int3/breakpoint into the guest kernel at the entry point to sys_open. When the breakpoint is hit, the program might set the guest instruction pointer to the address to which sys_open would have itself returned and set register RAX to some desired error-code return value. The problem I am encountering is that for some reason the process is triggering a "uprobe ... failed to handle uretprobe" message from the guest kernel. I do not yet know enough about uprobes to understand what might be causing this. Is there something in procedures such as sys_open which must execute to prevent the error which causes the kernel to print this message? -- Mike :wq

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