I was reminded off-list by someone who knows WAS better than I do that unzipping of JAR files renders content sharing moot. Sad, but true. JIT does the same thing.
So ... I am a huge fan of XIP, and we should all use it more. But we still have "opportunities" in all application areas. Even when the sharing is hindered, using DCSS for filesystems is a great advantage. VM can manage the storage. Then if you have content in a DCSS backed filesystem which can utilize mmap(), XIP comes into play and makes things just that much better. -- R; <>< Rick Troth Velocity Software http://www.velocitysoftware.com/ On Fri, Mar 18, 2011 at 08:57, Richard Troth <vmcow...@gmail.com> wrote: > You get a double benefit from XIP. Not only is the content shared by all > guests (so if just one guest is using it, CP has already paged it in), but > from the Linux perspective it is "point and shoot". (That's why they call > it execute in place. But you knew that.) Ordinarily, programs have to be > copied from a filesystem into memory, even if the filesystem is backed by > memory rather than disk. > > -- R; <>< > > > > > On Mar 18, 2011 8:32 AM, "Mark Wheeler" <mwheele...@hotmail.com> wrote: >> Mark, >> >> That's an excellent suggestion, inasmuch as we have a couple dozen of >> these servers running and, if nothing else, sharing code could reduce >> overall demand for memory. Obviously, the bigger win would be if this is the >> code that is actually being paged in and causing the delays, since by >> sharing it would be more likely to be in storage already. >> >> The larger problem is going to be getting buy-in from the app owner to >> implement such a thing. >> >> Best regards, >> >> Mark >> >> >>> Date: Thu, 17 Mar 2011 14:55:07 -0600 >>> From: mp...@novell.com >>> Subject: Re: Where is kernel loaded in memory? >>> To: LINUX-390@VM.MARIST.EDU >>> >>> >>> On 3/17/2011 at 04:47 PM, Marcy Cortes >>> >>> <marcy.d.cor...@wellsfargo.com> wrote: >>> > When you have some memory intensive night time activities, like say >>> > scanning >>> > checks in cron jobs, or heavy batch stuff, these things happen. We >>> > added >>> > more memory :(, although lowering the heap size did help some. >>> > >>> > Anyway you can prime the pump (script to touch your pages in a cron >>> > job?)? >>> >>> Putting the application into an xip2 file system on a DCSS might help >>> with this quite a bit. >>> >>> >>> Mark Post >>> >>> ---------------------------------------------------------------------- >>> For LINUX-390 subscribe / signoff / archive access instructions, >>> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or >>> visit >>> http://www.marist.edu/htbin/wlvindex?LINUX-390 >>> ---------------------------------------------------------------------- >>> For more information on Linux on System z, visit >>> http://wiki.linuxvm.org/ >> >> ---------------------------------------------------------------------- >> For LINUX-390 subscribe / signoff / archive access instructions, >> send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or >> visit >> http://www.marist.edu/htbin/wlvindex?LINUX-390 >> ---------------------------------------------------------------------- >> For more information on Linux on System z, visit >> http://wiki.linuxvm.org/ > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
