TODO

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PA-RISC Linux TODO (actually this is Helge's TODO list)

Updates for next newsletter

  • fixed 64bit SMP kernel & sticon on machines with more than 4GB RAM
  • Dave found O_SYNC bug in glibc
  • Migration parisc-linux.org
  • debian-ports.org access

Status & TODO 2013-12-05 (TODO-List by Helge Deller)

  • Drop HP-UX-Support, change EWOULDBLOCK=EAGAIN, possibly change number of signals (for systemd), .. what else? (I believe we should pull the plug on HP-UX entirely. If there ever was enough interest, It should be supported in a VM. Machines are relatively cheap now. So, if someone needs hpux, they can buy a machine for it.)

We have a more diverse user space under Linux and I believe in supporting open source, so we should focus on it.

  • Native types in uapi/asm/stat.h
  • From Dave: gcc thread issues including thread cancellation, glib2.0 problem,
  • use CONFIG_COMPAT_BINFMT_ELF and get rid of arch/parisc/kernel/binfmt_elf32.c
  • gcc-4.8 switch on debian, perl-bug (mmap of small files).
  • CONFIG_LONGCALL=n problems?, see: http://lwn.net/Articles/439472/ -> convert to sparsemem (http://lwn.net/Articles/440056/), patch available from James
  • add wiki page about kernel cross-compiling
  • send patches to remove UP from debian kernels, use sil680 instead of siimage, see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721191
  • gdb crashes Kernel - http://permalink.gmane.org/gmane.linux.ports.parisc/5406
  • glib2.0 atomic bug: Dave: I see the problem building various packages -- apt is is one. It occurs when multiple dot processes are started by graph when package documentation is being generated. The number of dot processes spawned depends on the number of processors on the build system. However, the faults occur even on a UP system. I debugged one of these segvs enough to see that the problem occurred in a glib2.0 library. It's using the GCC "sync" interface.
  • return ((unsigned long) mapping >> 7) & ((SHMLBA >> PAGE_SHIFT) - 1); in arch/parisc/kernel/sys_parisc.c
  • debian parisc perl bug (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=721537) shows that mmap on parisc linux is horribly inefficient. We allocate huge maps for small files. This should be improved. Mailthread: " parisc mmap: private file maps" ,http://www.spinics.net/lists/linux-parisc/msg05083.html or https://rt.perl.org/Public/Bug/Display.html?id=119567
  • More signals? > Can we change _NSIG to 69 so there are 32 RT signals as on other arches? It looks like it needs to be a power of 2. MIPS uses 128.
  • Kernel: still missing Linux kernel development (no patches available yet):
    • optimize flush_dcache_page() implementation like sparc. See Documentation/cachetlb.txt, e.g. used in aio subsystem
    • implement .con_font_set (consw) in sticon.c (to be able to change fonts at runtime)
    • Implement CONFIG_DEBUG_STACK_USAGE ?
    • fix wrong _init notation in kernel
    • NO_IRQ -> should be converted to (0) instead of (-1) -> Helge (check assembly, check in drivers/parisc/*)
    • implement alternative coding for UP/SMP. See arch/x86/include/asm/alternative.h
    • check assembly in drivers/parisc/*
    • use pdc_add_valid() in kern_addr_valid(), protect against crashable acesses (like for superio-pc-drivers-detection in lp), add pdc_add_valid() to create a probe_kernel_read() implementation.
    • arch/parisc/kernel/sys_parisc.c -> use SYSCALL_ALIAS() -> maybe
    • on C8000, report 1 socket with 2 cores.
    • implement HUGE pages (or even better transparent huge pages)
    • Review gettimeofday and clock_gettime() implementation, possibly use a light-weight-syscall and rely on cr16 and cpu speed for more accurate timing? similiar to commit http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=18ad51dd342a7eb09dbcd059d0b451b616d4dafc
  • Kernel: Low priority patches needs further work
    • Fix exception table entries to be of type int (32bit), even on 64bit kernel -> saves space. - https://patchwork.kernel.org/patch/3033801/
    • disable FP-register save/restore at kernel entry? - Helge
    • enable 16k/64k kernel page sizes (still cacheflushing-issues with SCSI driver, additional work in glibc needed to deal with >4k page size, e.g. ld-loader alignments of data/code segments)
    • Superdome support - can someone test? Should work better now with latest kernels.
    • task_struct/thread_info split -- task_struct should not be visible in entry.S, we need to move some items into thread_info -- this includes pt_regs and maybe some of the flags (ptrace, etc)
    • Visualize FX support (will probably never happen!)
  • Debian packaging work:
    • Build real debian-installer CD. See: https://wiki.debian.org/Simple-CDD/Howto
    • DONE: we need a kernel debian package (3.10 based or higher)
    • ONGOING: debian-ports/parisc repository aka. syning debs to there
    • DONE: split repository on parisc-linux.org into stable (wheezy) and unstable (sid)
  • Debian packages / Userspace work
    • IMPORTANT: fix OpenJDK - fixes required in zeroport (stack grows up!).
    • 64-bit userspace, 64-bit binutils needs to be fixed to get multiple stub section support.
    • gcc -> join 32- and 64bit compiler, make "-m64" work, get rid of hppa64-linux-gnu-gcc
  • Homepage migration:
    • ONGOING: Migration of parisc-linux.org website to https://parisc.wiki.kernel.org
    • Domain ownwer: Matt Taggart <matt@lackof.org>, Expiration Date:09-Aug-2014 23:07:58 UTC
    • DNS takeover by Thibaut Varenet on 11/11/2013 - see: http://article.gmane.org/gmane.linux.ports.parisc/5478
    • New domain owner: Thibaut VARENE <T-Bone@parisc-linux.org> <T-Bone@slashdirt.org>
    • Server administrator of parisc-linux.org: Dann Frazier - dannf@dannf.org
    • Technical contact at HP: brett.johnson@hp.com
  • palo (PA-RISC Boot Loader):
    • Modify (if possible), that palo can read (sequential) tftpbootable-vmlinuxes as well as the current boot-vmlinux images (simplifies build/handling)
    • add xz-compression support, maybe move decompression to Linux kernel instead of palo?

DONE


Kernel Testing Tools

TODO Drivers

  • IPMI support on rp-class / Support graceful shutdown from BMC on rp servers (`PC -GRACEFUL`)
  • write Lasi floppy driver
  • write Suckyio floppy driver
  • write spifi driver (rbrad)
  • modify ncr53c8xx driver for Outfield (735 & 755)
  • write GSC FDDI driver
  • write Timi ASIC (74x) support
  • EISA DMA support

Review all the todo entries below!

  • ns87415 dma doesn't work reliably on suckyio-systems
  • investigate not putting in extable entries for put_kernel_asm; will probably reduce kernel size
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