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| -rw-r--r-- | open_issues/smp.mdwn | 59 |
1 files changed, 56 insertions, 3 deletions
diff --git a/open_issues/smp.mdwn b/open_issues/smp.mdwn index b0287a48..0be706e3 100644 --- a/open_issues/smp.mdwn +++ b/open_issues/smp.mdwn @@ -38,6 +38,59 @@ https://en.wikipedia.org/wiki/File:SMP_-_Symmetric_Multiprocessor_System.svg --> # Current Status +As of September 2024, the SMP support is implemented for i386 with +working internet, because it boots with only one cpu in the default +processor set. The slave processors are temporarily disabled until +they can be safely used per task. We are unable to turn on the full +set at boot time due to race bugs. Debian Hurd provides SMP enabled +GNU Mach kernels. + +# How to test the current SMP support + +The easiest way to test the SMP support, is via the [[qemu +guide|https://www.gnu.org/software/hurd/hurd/running/qemu.html]]. +Once you have the Hurd running you can build an SMP enabled GNU Mach. + + $ git clone git://git.savannah.gnu.org/hurd/gnumach.git + $ cd gnumach + $ autoreconf -i + $ mkdir build + $ cd build + $ ../configure --enable-ncpus=4 --enable-apic --enable-kdb --disable-linux-groups + $ make gnumach.gz + $ su + # mv /boot/gnumach-1.8-486.gz /boot/gnumach-1.8-486.gz.bak + # cp gnumach.gz /boot/gnumach-1.8-486.gz + +You may optionally update `/boot/grub/grub.cfg` change `hd0` to `wd0` +and add `console=com0` + + /boot/gnumach-1.8-486.gz root=part:2:device:wd0 console=com0 + +update `/etc/fstab` and update `wd0` instead of `hd0`. + +``` +/dev/wd0s2 / ext2 defaults 0 1 +/dev/wd0s1 none swap sw 0 0 +``` + +You can shutdown via `/sbin/poweroff`. + +start qemu with `-smp 4` and add `-nographic` if you want to use `com0`. + + $ qemu-system-i386 -M q35,accel=kvm -smp 4 -m 2G -net \ + user,hostfwd=tcp::2223-:22 -net nic -hda debian-hurd-VERSION.img \ + -nographic + +To test smp: + + $ sudo /path/to/smp /bin/bash + $ stress -c 7 + +smp.c source can be found +[[here|https://lists.gnu.org/archive/html/bug-hurd/2024-02/msg00088.html]]. + +# What was done to get the 32-bit SMP support The GNU Mach source code includes many special cases for multiprocessor, controlled by #if NCPUS > 1 macro. @@ -95,7 +148,7 @@ have to build an isolated environment to execute the non-thread-safe drivers. ### Task list -1. Implement a routine to detect and identify the processors +1. DONE Implement a routine to detect and identify the processors This routine must check the number of processors, initialize the lapic of BSP (the master processor), and assign a kernel ID for each processor. This kernel @@ -180,7 +233,7 @@ have to build an isolated environment to execute the non-thread-safe drivers. Kernel/APIC array until it finds the same APIC ID. Then it will return the index (Kernel ID) of this position. -2. Implement a routine to initialize the processors +2. DONE Implement a routine to initialize the processors This routine will initialize the lapic of each processor and other structures @@ -191,7 +244,7 @@ have to build an isolated environment to execute the non-thread-safe drivers. Developer Guide, Volume 3. [link](https://software.intel.com/sites/default/files/managed/a4/60/325384-sdm-vol-3abcd.pdf) -3. Implement `intel_startCPU()` +3. DONE Implement `intel_startCPU()` This function will initialize the descriptor tables of the processor specified by the |