GNU/Linux S5R3 App 4.09 available for Beta test

A new Linux App is available from our Beta Test page.

It has a number of new features:

- The most important difference is the new handling of floating-point problems that previously showed up as "Input domain error" or "Non-finite Dphi_alpha" (exit status 99). Instead of checking critical values for being finite at certain points the App will now throw a floating-point execption (FPE) when a NaN or a FPU stack error is encountered. First this allows us to remove the time-consuming explicit finite checks, and second this gives us a clearer idea where in the code these problems actually happen. (We are not sure whether these only occur on machines with hardware problems (usually too hot CPU), or whether there is still a software bug left). These errors should now show up with an exit status 8 and a stack dump in stderr output.

- Apparently the slight modifications we made to the code in the last minute when switching to S5R3 confused the branch prediction of gcc for a case distinction in the innermost loop of the program, which had a severe impact on performance. We now added a hint to gcc to optimize the more frequently used path.

- The new checkpointing code that was previously seen on the 4.07 Windows App has been used here, too. An (unwanted) side effect is that the checkpoint files are incompatible with the current official Linux App, so there is no picking up of tasks in progress by a different App. The app_info.xml in this package, however, should allow for completing tasks that have been assigned to 4.02 with this App, and new tasks should be assigned to 4.09, so you should be able to switch to anonymous platform at any time.

- From the 4.07 Windows App this one also inherits the possibility of disabling the graphics (thread) by putting a file EAH_NO_GRAPHICS into the BOINC folder; no messing with graphics installation or the .so file is required.

BM