7 ms·

This is one of the reasons I prefer to use Linux over systems such as Windows or OSX. I love the public discussion over the direction of technical details; the

by phaemon 13y ago

This is one of the reasons I prefer to use Linux over systems such as Windows or OSX. I love the public discussion over the direction of technical details; the to-and-fro on the benefits of esoteric technologies. The whole openness of the culture.

mrb 13y ago
There is not much discussion about Windows internals, not only because they are not shared, but also because quite frankly the Windows kernel evolves slower than the Linux kernel in terms of new algorithms implemented. For example it is almost certain that Microsoft never tested I/O schedulers, process schedulers, filesystem optimizations, TCP/IP stack tweaks for wireless networks, etc, as much as the Linux community did. One can tell just by seeing the sheer amount of intense competition and interest amongst Linux kernel developers to research all these areas. The net result of that is a generally acknowledged fact that Windows is slower than Linux when running complex workloads that push network/disk/cpu scheduling to its limit: https://news.ycombinator.com/item?id=3368771 https://news.ycombinator.com/item?id=3368771 A really concrete and technical example is the network throughput in Windows Vista which is degraded when playing audio! http://blogs.technet.com/b/markrussinovich/archive/2007/08/27/1833290.aspx http://blogs.technet.com/b/markrussinovich/archive/2007/08/2... Note: my post may sound I am freely bashing Windows, but I am not. This is the cold hard truth. Countless of multi-platform developers will attest to this, me included. I can't even remember the number of times I have written a multi-platform program in C or Java that always runs slower on Windows than on Linux, across dozens of different versions of Windows and Linux. The last time I troubleshooted a Windows performance issue, I found out it was the MFT of an NTFS filesystem was being fragmented; this to say I am generally regarded as the one guy in the company who can troubleshoot any issue, yet I acknowledge I can almost never get Windows to perform as good as, or better than Linux, when there is a performance discrepancy in the first place.
- chinpokomon 13y ago
  Well Mark's post was interesting, but this is also old news now, is it not? Microsoft has had two OS updates since then and hot fixes and service packs. The biggest difference I see is that the Linux Kernel can be tweaked to specific performance characteristics at build time, whereas Windows can only be altered by runtime configuration. depending on what you might want to change, you may not have that capability. Going back to the article about network latency while playing media, the breakdown seems to show that this was a bug, and bugs happen. To Linux's credit, those bugs are probably patched more quickly and even if it hasn't been promoted to release, if someone has made a patch, you can incorporate your own fix. If not, the landscape doesn't look any different for Linux vs. Windows in that regard.
  - mrb 13y ago
    I have never seen a description or mention of a bugfix for this Vista problem. The root of the issue is that DPCs are very CPU-intensive due to the inherent design of the Windows network stack and drivers. A bug like this just does not "simply" happen as you make it seem. The root cause is lack of innovation in the kernel. The bloat does not get fixed. The software architecture they used to handle 10/100 Mbps of network traffic does not scale to 1000 Mbps.
    - cokernel_hacker 13y ago
      Can you please elaborate on this inherent design flaw? My understanding of NTOS DPCs is that they are quite similar to Linux tasklets/bottom-half interrupt handlers.
      - aionescu 13y ago
        A simple problem is that DPCs are not scheduled in any way (there's some very primitive queueing and delivery algorithms), or more importantly, are not scheduled in any way that correlates with the thread scheduler's view. So between four cores, if Network DPC/ISRs are abusing Core 1, but the thread scheduler sees an idle-ish low priority thread using up Core 0, and Core 1, 2, 3 are all Idle (because it doesn't understand DPCs/ISRs), it'll pick Core 1 for this thread (just because round-robin). I'm omitting NUMA/SMT and assuming all of these are 4 regular cores on the same socket. One could argue a better decision would've been to pick Core 2 and/or 3, but there's nothing to guide the scheduler to make this decision. But it's not that "DPCs" are a design flaw. It's the way that Windows drivers have been encouraged by Microsoft to be written. You'll see most Windows drivers have an ISR and DPC. If you look at IOKit (Mac's driver framework), almost all drivers run at the equivalent of Passive Level (IRQL 0) outside of the ISR/DPC path -- the OS makes sure of that. Because Windows driver devs are encouraged to write ISR/DPC code, and because this code runs at high IRQL, it means that bugs and inefficiencies in drivers show a much larger performance degradation. And when you buy a shit 0.01$ OEM NIC, and you have to do MAC filtering, L2 layering, checksum validation and packet reconstruction in your DPC, plus there's no MSI and/or interrupt coalescing, you're kind of f*cked as a Windows driver.
- deleted 13y ago
  [deleted]
- deleted 13y ago
  [deleted]
  - mrb 13y ago
    Reposted here: http://blog.zorinaq.com/?e=74 http://blog.zorinaq.com/?e=74 This is too insightful to be lost in the cracks of HN. And here: https://news.ycombinator.com/item?id=5689731 https://news.ycombinator.com/item?id=5689731 :)
  - gizmo686 13y ago
    The original author has requested that the hash and filename he used in the begging to prove his identity be removed.
    - mrb 13y ago
      Can't edit the post :( I emailed pg@ and info@ycombinator.com an hour ago already to ask for redaction.
      - mpyne 13y ago
        Can you delete it and re-post a redacted one?
        mrb 13y ago
        I had pg@ delete my HN post, so to leave only the properly re-edited version on my blog.
  - deleted 13y ago
    [deleted]
  - varent 13y ago
    I have the same experience in an established tech company in the bay area. Exactly the same has happened - lots of new hires. Bad management. Really silly review process. Features are valued over fixing things. There's no mentorship process for said new hires. This has obvious flow-on effects. The old timers don't get promoted into management but end up fixing more and more bugs (because they're the ones that know stuff well enough to fix said bugs.) They get frustrated and leave, or they just give up and take a pay check. The management values "time to deliver" over any kind of balance with "fix existing issues", "make things better", "fix long standing issues", "do code/architecture review to try and improve things over the long run." They're going to get spanked if anyone shows up in their marketspace. Oh wait, but they're transitioning to an IP licensing company instead of "make things people buy." So even if they end up delivering crap, their revenue comes from licensing patents and IP rather than making things. Oops. Thank god there's a startup mentality in the bay area.
- redstripe 13y ago
  That deleted post from the MSFTer is pretty damning, but is the difference one that really matters? Take a look at these benchmarks that were posted here recently: https://news.ycombinator.com/item?id=5644880 https://news.ycombinator.com/item?id=5644880 There isn't a single comment in that whole thread about how outrageously bad EC2 performance is. Meanwhile I'd bet that most HN startups run on EC2, heroku or other virtualized cloud platforms. And how many are using dog slow interpreted languages like python or ruby? It looks to me like people around here are quite willing to take very large performance hits for the sake of convenience. I find Windows to be a small performance hit for the sake of convenience.
  - olalonde 13y ago
    As a developer, I fail to see in what way is Windows convenient.
    - chippy 13y ago
      um, it comes on the computer already installed? .... I know weak, but it's the only idea I could think of.
      - Anon_Cow 13y ago
        You can buy computers with Linux pre-installed nowadays too. I used to use Windows exclusively until about 4 years ago. Up to the time i switched, I occasionally was testing a few Linux distros, and repeatedly came to the conclusion that drivers were still an issue, and that Linux wasn't ready for the average user's desktop. Not so anymore, since about 2009. From that time on, the only thing without a Linux driver I encountered (there are many more, just not that widespread that it should matter) was an HP printer. Which is why I stopped using Windows altogether. My experience since then? Windows is a royal PITA to use and maintain. Linux, with KDE as the desktop manager, isn't just faster, it's way friendlier for users. One example, which to me is huge: on Windows, you need to run the updater of every f..ing software provider from which you have purchased an app. On Linux, there's just one updater for everything. another one: on Windows, even with all the discount programs for students and others, you have to spend thousands of dollars before you get equivalents of all apps installed that you get for free when you select developer workstation for a Linux installer. Agreed, games are the only thing that Linux doesn't yet cover as well as Windows - both development and play. However, wanna bet that Linux will tip the balance in this area too, in at most five years?
- ksk 13y ago
  Sorry, I have never noticed Windows being slower than Linux. And usually when people complain, they usually have an incomplete understanding of what they're doing (nothing personal!). The links that you posted in support of your claim are irrelevant IMO. Compiling has nothing whatsoever to do with windows internals. You're comparing Visual Studio a full fledged IDE with dozens of extra threads running source indexing, source code completion/help indexing and dozens of other things that gcc does not do. To make a fair comparison you will have to just compare cl.exe with gcc with a bunch of makefiles (yes you can have makefiles on windows too). Then your "real concrete and technical" example is actually a bug in windows vista which was fixed around 6 years ago. And your claim about MFT fragmentation kind of sounds bizzare to be honest. Since Vista the OS internally runs a scheduled task to run a partial-defrag that takes care of it. I'm not sure what went wrong in your case. I'm not saying you imagined the slowness, I believe you experienced what you said. So lets test your theory. Since you can write code runs slower only on Windows - give us some C code that runs horribly on Windows.
  - vilanye 13y ago
    There is a rather large difference between "runs slower" and "runs horribly". What you did is try to move the goal posts.
    - ksk 13y ago
      What? What "goal posts"? Jesus.. not everything is a nerd war to prove something right/wrong. I have no emotional investment in the outcome. I guess the only solution is to tag my comments "Hey this is a casual conversational comment" or else people read too much into the wording.
- cpsales 13y ago
  I always had the feeling that Microsoft is made up of two types of developers: 1) noobs like those who created the MetroUI and have absolutely no knowledge of the Windows history - they always introduce new and pointless features, and they also usually undo the work of the other type of developer: 2) geniues (this is not a pun), like those who improved Windows performance so much starting with Windows XP and who know both the history and the users of Windows inside-out
- asdqwezxc 13y ago
  http://pastebin.com/KXpg5wgz http://pastebin.com/KXpg5wgz
- Anon_Cow 13y ago
  `

by phaemon 13y ago

mrb 13y ago

There is not much discussion about Windows internals, not only because they are not shared, but also because quite frankly the Windows kernel evolves slower than the Linux kernel in terms of new algorithms implemented. For example it is almost certain that Microsoft never tested I/O schedulers, process schedulers, filesystem optimizations, TCP/IP stack tweaks for wireless networks, etc, as much as the Linux community did. One can tell just by seeing the sheer amount of intense competition and interest amongst Linux kernel developers to research all these areas. The net result of that is a generally acknowledged fact that Windows is slower than Linux when running complex workloads that push network/disk/cpu scheduling to its limit: https://news.ycombinator.com/item?id=3368771 https://news.ycombinator.com/item?id=3368771 A really concrete and technical example is the network throughput in Windows Vista which is degraded when playing audio! http://blogs.technet.com/b/markrussinovich/archive/2007/08/27/1833290.aspx http://blogs.technet.com/b/markrussinovich/archive/2007/08/2... Note: my post may sound I am freely bashing Windows, but I am not. This is the cold hard truth. Countless of multi-platform developers will attest to this, me included. I can't even remember the number of times I have written a multi-platform program in C or Java that always runs slower on Windows than on Linux, across dozens of different versions of Windows and Linux. The last time I troubleshooted a Windows performance issue, I found out it was the MFT of an NTFS filesystem was being fragmented; this to say I am generally regarded as the one guy in the company who can troubleshoot any issue, yet I acknowledge I can almost never get Windows to perform as good as, or better than Linux, when there is a performance discrepancy in the first place.

chinpokomon 13y ago
Well Mark's post was interesting, but this is also old news now, is it not? Microsoft has had two OS updates since then and hot fixes and service packs. The biggest difference I see is that the Linux Kernel can be tweaked to specific performance characteristics at build time, whereas Windows can only be altered by runtime configuration. depending on what you might want to change, you may not have that capability. Going back to the article about network latency while playing media, the breakdown seems to show that this was a bug, and bugs happen. To Linux's credit, those bugs are probably patched more quickly and even if it hasn't been promoted to release, if someone has made a patch, you can incorporate your own fix. If not, the landscape doesn't look any different for Linux vs. Windows in that regard.
- mrb 13y ago
  I have never seen a description or mention of a bugfix for this Vista problem. The root of the issue is that DPCs are very CPU-intensive due to the inherent design of the Windows network stack and drivers. A bug like this just does not "simply" happen as you make it seem. The root cause is lack of innovation in the kernel. The bloat does not get fixed. The software architecture they used to handle 10/100 Mbps of network traffic does not scale to 1000 Mbps.
  - cokernel_hacker 13y ago
    Can you please elaborate on this inherent design flaw? My understanding of NTOS DPCs is that they are quite similar to Linux tasklets/bottom-half interrupt handlers.
    - aionescu 13y ago
      A simple problem is that DPCs are not scheduled in any way (there's some very primitive queueing and delivery algorithms), or more importantly, are not scheduled in any way that correlates with the thread scheduler's view. So between four cores, if Network DPC/ISRs are abusing Core 1, but the thread scheduler sees an idle-ish low priority thread using up Core 0, and Core 1, 2, 3 are all Idle (because it doesn't understand DPCs/ISRs), it'll pick Core 1 for this thread (just because round-robin). I'm omitting NUMA/SMT and assuming all of these are 4 regular cores on the same socket. One could argue a better decision would've been to pick Core 2 and/or 3, but there's nothing to guide the scheduler to make this decision. But it's not that "DPCs" are a design flaw. It's the way that Windows drivers have been encouraged by Microsoft to be written. You'll see most Windows drivers have an ISR and DPC. If you look at IOKit (Mac's driver framework), almost all drivers run at the equivalent of Passive Level (IRQL 0) outside of the ISR/DPC path -- the OS makes sure of that. Because Windows driver devs are encouraged to write ISR/DPC code, and because this code runs at high IRQL, it means that bugs and inefficiencies in drivers show a much larger performance degradation. And when you buy a shit 0.01$ OEM NIC, and you have to do MAC filtering, L2 layering, checksum validation and packet reconstruction in your DPC, plus there's no MSI and/or interrupt coalescing, you're kind of f*cked as a Windows driver.
deleted 13y ago
[deleted]
deleted 13y ago
[deleted]
- mrb 13y ago
  Reposted here: http://blog.zorinaq.com/?e=74 http://blog.zorinaq.com/?e=74 This is too insightful to be lost in the cracks of HN. And here: https://news.ycombinator.com/item?id=5689731 https://news.ycombinator.com/item?id=5689731 :)
- gizmo686 13y ago
  The original author has requested that the hash and filename he used in the begging to prove his identity be removed.
  - mrb 13y ago
    Can't edit the post :( I emailed pg@ and info@ycombinator.com an hour ago already to ask for redaction.
    - mpyne 13y ago
      Can you delete it and re-post a redacted one?
      - mrb 13y ago
        I had pg@ delete my HN post, so to leave only the properly re-edited version on my blog.
- deleted 13y ago
  [deleted]
- varent 13y ago
  I have the same experience in an established tech company in the bay area. Exactly the same has happened - lots of new hires. Bad management. Really silly review process. Features are valued over fixing things. There's no mentorship process for said new hires. This has obvious flow-on effects. The old timers don't get promoted into management but end up fixing more and more bugs (because they're the ones that know stuff well enough to fix said bugs.) They get frustrated and leave, or they just give up and take a pay check. The management values "time to deliver" over any kind of balance with "fix existing issues", "make things better", "fix long standing issues", "do code/architecture review to try and improve things over the long run." They're going to get spanked if anyone shows up in their marketspace. Oh wait, but they're transitioning to an IP licensing company instead of "make things people buy." So even if they end up delivering crap, their revenue comes from licensing patents and IP rather than making things. Oops. Thank god there's a startup mentality in the bay area.
redstripe 13y ago
That deleted post from the MSFTer is pretty damning, but is the difference one that really matters? Take a look at these benchmarks that were posted here recently: https://news.ycombinator.com/item?id=5644880 https://news.ycombinator.com/item?id=5644880 There isn't a single comment in that whole thread about how outrageously bad EC2 performance is. Meanwhile I'd bet that most HN startups run on EC2, heroku or other virtualized cloud platforms. And how many are using dog slow interpreted languages like python or ruby? It looks to me like people around here are quite willing to take very large performance hits for the sake of convenience. I find Windows to be a small performance hit for the sake of convenience.
- olalonde 13y ago
  As a developer, I fail to see in what way is Windows convenient.
  - chippy 13y ago
    um, it comes on the computer already installed? .... I know weak, but it's the only idea I could think of.
    - Anon_Cow 13y ago
      You can buy computers with Linux pre-installed nowadays too. I used to use Windows exclusively until about 4 years ago. Up to the time i switched, I occasionally was testing a few Linux distros, and repeatedly came to the conclusion that drivers were still an issue, and that Linux wasn't ready for the average user's desktop. Not so anymore, since about 2009. From that time on, the only thing without a Linux driver I encountered (there are many more, just not that widespread that it should matter) was an HP printer. Which is why I stopped using Windows altogether. My experience since then? Windows is a royal PITA to use and maintain. Linux, with KDE as the desktop manager, isn't just faster, it's way friendlier for users. One example, which to me is huge: on Windows, you need to run the updater of every f..ing software provider from which you have purchased an app. On Linux, there's just one updater for everything. another one: on Windows, even with all the discount programs for students and others, you have to spend thousands of dollars before you get equivalents of all apps installed that you get for free when you select developer workstation for a Linux installer. Agreed, games are the only thing that Linux doesn't yet cover as well as Windows - both development and play. However, wanna bet that Linux will tip the balance in this area too, in at most five years?
ksk 13y ago
Sorry, I have never noticed Windows being slower than Linux. And usually when people complain, they usually have an incomplete understanding of what they're doing (nothing personal!). The links that you posted in support of your claim are irrelevant IMO. Compiling has nothing whatsoever to do with windows internals. You're comparing Visual Studio a full fledged IDE with dozens of extra threads running source indexing, source code completion/help indexing and dozens of other things that gcc does not do. To make a fair comparison you will have to just compare cl.exe with gcc with a bunch of makefiles (yes you can have makefiles on windows too). Then your "real concrete and technical" example is actually a bug in windows vista which was fixed around 6 years ago. And your claim about MFT fragmentation kind of sounds bizzare to be honest. Since Vista the OS internally runs a scheduled task to run a partial-defrag that takes care of it. I'm not sure what went wrong in your case. I'm not saying you imagined the slowness, I believe you experienced what you said. So lets test your theory. Since you can write code runs slower only on Windows - give us some C code that runs horribly on Windows.
- vilanye 13y ago
  There is a rather large difference between "runs slower" and "runs horribly". What you did is try to move the goal posts.
  - ksk 13y ago
    What? What "goal posts"? Jesus.. not everything is a nerd war to prove something right/wrong. I have no emotional investment in the outcome. I guess the only solution is to tag my comments "Hey this is a casual conversational comment" or else people read too much into the wording.
cpsales 13y ago
I always had the feeling that Microsoft is made up of two types of developers: 1) noobs like those who created the MetroUI and have absolutely no knowledge of the Windows history - they always introduce new and pointless features, and they also usually undo the work of the other type of developer: 2) geniues (this is not a pun), like those who improved Windows performance so much starting with Windows XP and who know both the history and the users of Windows inside-out
asdqwezxc 13y ago
http://pastebin.com/KXpg5wgz http://pastebin.com/KXpg5wgz
Anon_Cow 13y ago
`