the kernel reportthe best solution someday. where are the patches? big.little switcher not upstream...
TRANSCRIPT
![Page 2: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/2.jpg)
The kernel report(and weather forecast)
(LinuxCon Japan 2013 edition)
Jonathan CorbetLWN.net
![Page 3: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/3.jpg)
In the dim and distant past
![Page 4: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/4.jpg)
In the dim and distant past
(May 20, 2012)
The 3.4 kernel was released
![Page 5: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/5.jpg)
Since then...
69,863 changesets merged3,173 developers have contributed360+ employers have contributed5 kernels releasedThe kernel is 1.57 million lines bigger
![Page 6: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/6.jpg)
Recent release history
Release Date Days Csets Devs3.4 May 20 63 10,899 1,2863.5 July 21 62 10,957 1,1953.6 Sep 30 71 10,247 1,2163.7 Dec 10 71 11,990 1,2713.8 Feb 18 70 12,394 1,2533.9 Apr 28 69 11,910 1,3393.10 12,776* 1,237*
* so far
![Page 7: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/7.jpg)
A few headline features
Bufferbloat fixesAndroid integrationdm-verity, dm-cachex32 ABISeccomp filtersUser namespacesuprobesTCP fast openBtrfs send/receive, RAIDKernel hardening
64-bit ARM supportOpenVSwitchNUMA balancingKernel mem. acc'tingARM single zImageARM virtualizationPer-entity load trackingMemory pressure notif.Dynamic tickXFS metadata checksum...
![Page 8: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/8.jpg)
Most active employers (3.4..)
(None) 11.3%Red Hat 9.8%Intel 8.4%(unknown) 7.2%Linaro 4.5%Texas Inst. 4.2%SUSE 3.3%IBM 3.0%Vision Engraving 3.0%Samsung 2.8%Google 2.5%
NVIDIA 1.4%Wolfson Micro 1.3%Oracle 1.3%Renasas Elect. 1.2%Freescale 1.2%consultants 1.2%Broadcom 1.2%Cisco 1.1%LINBIT 1.0%Inktank Storage 1.0%Ingics Tech 1.0%
![Page 9: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/9.jpg)
Mobile/embedded participation
![Page 10: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/10.jpg)
Lots going on out there
![Page 11: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/11.jpg)
Lots going on out there(as usual)
![Page 12: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/12.jpg)
The 3.10 kernel
Due in early July
Features(Nearly) full dynamic tickBcacheMultiple ftrace buffersMemory pressure notificationsTCP tail loss probingARM single zImage workXFS metadata checksumsArm big.LITTLE preparation...
![Page 13: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/13.jpg)
Scheduling
![Page 14: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/14.jpg)
NUMA balancing
![Page 15: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/15.jpg)
NUMA balancing
![Page 16: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/16.jpg)
NUMA balancing
![Page 17: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/17.jpg)
NUMA balancing
![Page 18: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/18.jpg)
NUMA balancing
![Page 19: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/19.jpg)
Toward better NUMA performance
NUMA scheduling framework added v3.8
Ideas:A “home node” for processesActively migrate pages when processes move...
![Page 20: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/20.jpg)
There's more
![Page 21: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/21.jpg)
Power-aware scheduling
Linux is very good when there's no work to do
The problem is easy on a busy system
![Page 22: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/22.jpg)
Power-aware scheduling
![Page 23: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/23.jpg)
Power-aware scheduling
![Page 24: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/24.jpg)
Approaches to power-aware scheduling
Pack small tasks togetherDon't let them wake multiple processors
Spread big tasks outTry to get to idle quickly
![Page 25: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/25.jpg)
Wait...there's more!
![Page 26: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/26.jpg)
big.LITTLE
![Page 27: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/27.jpg)
Approaches to big.LITTLE
Switch all CPUs transparently in a hypervisorAn apparent 4-CPU systemKernel is unaware of switching
![Page 28: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/28.jpg)
Approaches to big.LITTLE
Switch all CPUs transparently in a hypervisorAn apparent 4-CPU systemKernel is unaware of switching
Bundle pairs of big and little CPUsTreat it like frequency scaling“The big.LITTLE switcher”
![Page 29: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/29.jpg)
Approaches to big.LITTLE
Switch all CPUs transparently in a hypervisorAn apparent 4-CPU systemKernel is unaware of switching
Bundle pairs of big and little CPUsTreat it like frequency scaling“The big.LITTLE switcher”
Teach the scheduler about heterogeneous systems“big LITTLE MP” patches existThe best solution someday
![Page 30: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/30.jpg)
Where are the patches?
big.LITTLE switcherNot upstreamCode not yet recently posted
big LITTLE MPEarly-stage patches postedTrouble getting review and integration
![Page 31: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/31.jpg)
Why is this stuff hard to merge?
Fear of regressions
![Page 32: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/32.jpg)
Who hacks arch/arm* (3.3-3.9)
Linaro 15%Texas Instruments 12%(none) 7%consultants 7%ARM 6%NVIDIA 6%Samsung 5%Renesas Electronics 3%Atomide 3%Free Electrons 3%Freescale 3%Calxeda 2%
![Page 33: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/33.jpg)
Who hacks {kernel,mm,fs}/
Red Hat 25%SUSE 8%NetApp 8%Google 5%Parallels 5%(none) 4%IBM 4%Oracle 4%Linaro 4%Fujitsu 4%Intel 3%Arista Networks 3%
![Page 34: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/34.jpg)
“Linux kernel development is driven by the needs of enterprise
computing.”
![Page 35: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/35.jpg)
We have an interesting integration problem
![Page 36: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/36.jpg)
Why bother?
Maybe we need two kernels?One for enterprise / desktopOne for mobile / embedded
![Page 37: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/37.jpg)
Features inflicted upon embedded by the enterprise
Symmetric multi-processingSupport for >1GB of memory on 32-bit systemsThe ext3/ext4 filesystemsThe completely fair schedulerBest-of-breed networking…
![Page 38: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/38.jpg)
One kernel for everybody is one of our strengths
![Page 39: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/39.jpg)
What about Android?
Much code merged
Some has been replacedIncluding wakelocks!
Some remains outsideION memory manager…
Google continues to innovate
![Page 40: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/40.jpg)
Networking
![Page 41: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/41.jpg)
Multipath TCP
Your phone has (at least) two interfacesOnly one is used at a time
3G celltower
IP 1.2.3.4
IP 5.6.7.8
![Page 42: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/42.jpg)
Multipath TCP
What if both could be used together?
Better bandwidthTraffic can run across both links simultaneously
More reliablePaths can come and go - connection remains
![Page 43: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/43.jpg)
Useful in data centers too
![Page 44: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/44.jpg)
Multipath TCP status
Patches existLots of information on multipath-tcp.orgSpeed record for TCP claimedMainline merging still distant
But that's not the interesting part...
![Page 45: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/45.jpg)
The innovation-hostile net
Multipath TCP is complexFlow managementCongestion controlSecurity issues…
Where the real challenge was:The dreaded middlebox
![Page 46: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/46.jpg)
Middleboxes
These boxes will:Change IP addresses on the fly (ports too)Add or remove TCP flagsResegment dataACK undelivered dataCorrupt the data itselfBlock anything that looks “scary”
Thus:MPTCP must look exactly like TCP
![Page 47: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/47.jpg)
Network innovation comes to Linux first
![Page 48: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/48.jpg)
Network innovation comes to Linux first
...but...
![Page 49: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/49.jpg)
Deploying new protocols on the net has become nearly impossible.
![Page 50: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/50.jpg)
Other interesting stuff
![Page 51: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/51.jpg)
CPU isolation
When you must have the whole CPU to yourself
With 3.10:No timer tickNo RCU callbacks…
Useful for:High-performance computingRealtime
![Page 52: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/52.jpg)
Security
![Page 53: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/53.jpg)
Attackers are reviewing our code better than we are
![Page 54: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/54.jpg)
Some improvements
Better testingTrinity - fuzz testing
Kernel hardening efforts
Useful new technologiesUser namespaces...
![Page 55: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/55.jpg)
It's still not good enough.
![Page 56: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/56.jpg)
Innovation
![Page 57: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/57.jpg)
Different views of Linux
Classic LinuxKernelGNU libcSYSV initX11Desktop env
![Page 58: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/58.jpg)
Different views of Linux
Classic LinuxKernelGNU libcSYSV initX11Desktop env
AndroidKernelBionicinit.rcSurfaceFlingerDalvik
![Page 59: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/59.jpg)
Different views of Linux
Classic LinuxKernelGNU libcSYSV initX11Desktop env
AndroidKernelBionicinit.rcSurfaceFlingerDalvik
UbuntuKernelGNU libcupstartMirUnity
![Page 60: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/60.jpg)
Are we repeating the Unix wars?
![Page 61: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/61.jpg)
![Page 62: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/62.jpg)
Interesting things are now done on Linux first
![Page 63: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/63.jpg)
![Page 64: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/64.jpg)
![Page 65: The kernel reportThe best solution someday. Where are the patches? big.LITTLE switcher Not upstream Code not yet recently posted ... Lots of information on multipath-tcp.org Speed](https://reader034.vdocuments.mx/reader034/viewer/2022050102/5f41174aaf15ce11b64a93cb/html5/thumbnails/65.jpg)
It's up to us to find the path(s)