Re: Turkeys and dynamic linking
Michael Edenfield wrote: * Kent Stewart [EMAIL PROTECTED] [031127 17:50]: On Thursday 27 November 2003 12:31 pm, Bill Moran wrote: walt wrote: To all of you who celebrate Thanksgiving today, I wish you a happy one! And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? Don't they fix the performance hit by moving performance-critical parts of the application into kernel space (such as IIS and MSSQL)? At least, that's what Eric Raymond claims in his latest book. I don't think that's an approach I would like to see FreeBSD take. snip As far as moving things into the kernel, I'm not sure what ESR is referring to. It's easy to get code into kernel-space by making it a device driver, but AFAIK SQL Server code comes all from normal DLL libraries, all in user space. Looks like I overstated it a bit, from the book: While NT will use an MMU, NT versions after 3.5 have the system GUI wired into the same address space as the privileged kernel for performance reasons. Recent versions even wire the webserver into kernel space in an attempt to match the speed of Unix-based webservers. -- Bill Moran Potential Technologies http://www.potentialtech.com ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
Turkeys and dynamic linking
To all of you who celebrate Thanksgiving today, I wish you a happy one! And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Turkeys and dynamic linking
On Thu, 2003-11-27 at 15:15, walt wrote: And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? My understanding is that they perform a special linking/postprocessing step which optimizes executables for fast runtime linking and loading. -- brandon s. allbery[linux,solaris,freebsd,perl] [EMAIL PROTECTED] system administrator [WAY too many hats][EMAIL PROTECTED] electrical and computer engineering, carnegie mellon univ. KF8NH ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Turkeys and dynamic linking
walt wrote: To all of you who celebrate Thanksgiving today, I wish you a happy one! And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? Don't they fix the performance hit by moving performance-critical parts of the application into kernel space (such as IIS and MSSQL)? At least, that's what Eric Raymond claims in his latest book. I don't think that's an approach I would like to see FreeBSD take. -- Bill Moran Potential Technologies http://www.potentialtech.com ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Turkeys and dynamic linking
On Thursday 27 November 2003 12:31 pm, Bill Moran wrote: walt wrote: To all of you who celebrate Thanksgiving today, I wish you a happy one! And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? Don't they fix the performance hit by moving performance-critical parts of the application into kernel space (such as IIS and MSSQL)? At least, that's what Eric Raymond claims in his latest book. I don't think that's an approach I would like to see FreeBSD take. It all depends because if you only have 1 dll loaded for multiple applications, which is one of the features I understand is built into Windows, you have real savings. You share the code and own the data. Kent -- Kent Stewart Richland, WA http://users.owt.com/kstewart/index.html ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: Turkeys and dynamic linking
* Kent Stewart [EMAIL PROTECTED] [031127 17:50]: On Thursday 27 November 2003 12:31 pm, Bill Moran wrote: walt wrote: To all of you who celebrate Thanksgiving today, I wish you a happy one! And speaking of turkeys, does anyone know how Microsoft handles the performance issues associated with dynamic linking? Do they do anything special, or just ignore the whole thing? Don't they fix the performance hit by moving performance-critical parts of the application into kernel space (such as IIS and MSSQL)? At least, that's what Eric Raymond claims in his latest book. I don't think that's an approach I would like to see FreeBSD take. It all depends because if you only have 1 dll loaded for multiple applications, which is one of the features I understand is built into Windows, you have real savings. You share the code and own the data. Windows' dynamic linker works in a similar way to what Apple does in terms of sharing dll code. It makes an attempt to load libraries at the same base address in all processes, so that one DLL can be easily mapped into multiple processes. When you build a DLL, you supply a preferred address where it should be loaded. If Windows can load the library there, it does so. It also tries to load DLL's in thh same order each time. Since every process in the system likely relies on kernel32.dll, and probably user32.dll and gdi32.dll and others, Windows is almost always able to put those libraries at the same place in each process. So it doesn't have to read kernel32.dll from disk, since the OS itself has it loaded from the beginning. It just needs to do the fixups. For user-defined libraries, there's a decent chance that the same thing will happen. If not, then you have to pay the penalty to remap the library from scratch into a new location. As far as moving things into the kernel, I'm not sure what ESR is referring to. It's easy to get code into kernel-space by making it a device driver, but AFAIK SQL Server code comes all from normal DLL libraries, all in user space. --Mike pgp0.pgp Description: PGP signature
