The Linux 6.15 kernel is set to remove support for IBM Cell Blade servers for those server platforms from around two decades ago that used the Cell Broadband Engine Architecture processors. IBM Cell Blades at the time powered a few supercomputers but these IBM QS20 / QS21 / QS22 platforms are no longer relevant and the IBM Linux kernel maintainers no longer even have these platforms available/running. With no apparent users remaining, it’s time to say goodbye to the IBM Cell Blades from the mainline kernel.
Back in December I wrote about the situation that Linux was looking to drop support for IBM Cell Blade servers. That death sentence has arrived with those removal patches submitted as part of the IBM PowerPC updates for the Linux 6.15 merge window.
Dropping support for the IBM Cell Blade servers lightens the kernel by some 6k lines of code and with no apparent users left running modern Linux installations on these aging servers, it’s a win-win.
The PowerPC updates for Linux 6.15 meanwhile add support for inline static calls on PPC32, enable hardware trace macro (HTM) HCALL support, support for limited address mode capability, and introduce SMP support for the OpenPOWER Microwatt. That soft processor core based on Power ISA 3.0 now supports a 2-core version with the upstream kernel code.
See the POWER pull request for the full list of POWER-related changes — and IBM Cell Blade removal — for the Linux 6.15 kernel.
