Re: GSoC 2016
In article , Hrishikesh goyal wrote: >-=-=-=-=-=- > >Hello Sir, > >Alright, I started some ext2fs specific thing, and trying to understand the >code. And I refer to Linux docs for understanding of ext4fs. The heading in >my ext4fs understanding includes documentation >For "extents" and "block groups". >Another term for research: multiblock alllocator. > >I cloned NetBSD src on Linux. I am thinking of building cross compiler for >NetBSD on Linux >Kindly instruct me further There is already a way to cross-compile NetBSD on linux. There is a build.sh script on the top level directory that will do all the work for you and a "BUILDING" file with instructions. OTOH, you might invest some time installing NetBSD on a real machine or an emulator just to become more familiar with the system before starting to work on it. christos
Re: Interrupt time inflation on Xen
Le 2016-03-14 13:40, Thor Lancelot Simon a écrit : On Mon, Mar 14, 2016 at 12:10:29PM +0100, Jean-Yves Migeon wrote: And same question applies if you reduce bs (128m from 1g for example) I'll run the other test today or tomorrow -- this one's a "no" -- the problem is just as bad with bs=64k Alright. (did I say I was using a 1g blocksize before? I wasn't, I was using a 1m blocksize). Fair point :o When you get used to 1K blocks output... -- Jean-Yves Migeon
Re: Interrupt time inflation on Xen
On Mon, Mar 14, 2016 at 12:10:29PM +0100, Jean-Yves Migeon wrote: > > And same question applies if you reduce bs (128m from 1g for example) I'll run the other test today or tomorrow -- this one's a "no" -- the problem is just as bad with bs=64k (did I say I was using a 1g blocksize before? I wasn't, I was using a 1m blocksize). -- Thor Lancelot Simont...@panix.com "We cannot usually in social life pursue a single value or a single moral aim, untroubled by the need to compromise with others." - H.L.A. Hart
Re: Interrupt time inflation on Xen
On 2016-03-14 00:08, Thor Lancelot Simon wrote: I had occasion a couple of days ago to try to block-copy a very large filesystem from a xen dom0 to another machine across a fast local network. I tried this: sysctl -w kern.sbmax=1000 sysctl -w net.inet.tcp.sendbuf_auto=0 dd if=/dev/rsd0g bs=1048576 | ttcp -t -b 2097152 -l 131072 -fm -p 9001 172.0.0.1 On the far end, I had simply the corresponding ttcp -r job (with corresponding socket/tcp sysctls in place) redirected to a file. The underlying hardware is a RAID5 of 300GB SAS drives on an Areca 1680. The Ethernet controller in use is a 'wm'. All supported offload functionality is turned on (turning it off just slows things down). Shockingly, I saw the system go to 0% idle time, with 45-55% "Interrupt" and the rest "System". Interrupts per second were a comparatively low 1500, about 500 disk and 1000 network. Throughput was horrible -- about 35MB/sec. This might not be related, or useful, but it do sound similar to what I've been seeing on VAXen for a few years now. I get unexpectedly high interrupt rates, but most significantly, I can get ridiculous system time when doing something like a "cvs update". I have never had the time to try and figure it out, but I normally have over 50% (usually around 70%) in system when doing this. Which does not seem reasonable. But once more, this might be a red herring, so feel free to ignore. Johnny
Re: Interrupt time inflation on Xen
Le 2016-03-14 00:08, Thor Lancelot Simon a écrit : [snip] I am going to install a different disk controller and see what happens, but I am not totally optimistic. Does anyone have any idea what might be going on? Nope, but I would be interested in the throughput you get when you pipe dd if=/dev/rsd0g to /dev/null and dev/zero to ttcp (withou gzip), simultaneously. Do you see any difference in the disk throughput when stopping ttcp? And same question applies if you reduce bs (128m from 1g for example) -- Jean-Yves Migeon
Re: GSoC 2016
Hello Sir, Alright, I started some ext2fs specific thing, and trying to understand the code. And I refer to Linux docs for understanding of ext4fs. The heading in my ext4fs understanding includes documentation For "extents" and "block groups". Another term for research: multiblock alllocator. I cloned NetBSD src on Linux. I am thinking of building cross compiler for NetBSD on Linux Kindly instruct me further Hrishikesh On Fri, Mar 11, 2016 at 6:31 PM, Hrishikesh goyal < mhrishik...@student.nitw.ac.in> wrote: > Hi sir, > I am pursuing BTech (branch CSE) at National Institute of Technology > Warangal, (India). I have implemented a basic unix file system(system V fs) > with limited functionality for linux-kernel-3.13.0.48. Now I am interested > in contribution to open source especially in netbsd-filesystem project > (adding journalism in ext3fs or writing in ext4fs) by applying in GSoC > 2016. and improve my skills. Please instruct me further. > > Regards > Hrishikesh > > >
