linux/arch/ia64/kernel
Ingo Molnar 6cb54819d7 [PATCH] remove sys_set_zone_reclaim()
This removes sys_set_zone_reclaim() for now.  While i'm sure Martin is
trying to solve a real problem, we must not hard-code an incomplete and
insufficient approach into a syscall, because syscalls are pretty much
for eternity.  I am quite strongly convinced that this syscall must not
hit v2.6.13 in its current form.

Firstly, the syscall lacks basic syscall design: e.g. it allows the
global setting of VM policy for unprivileged users. (!) [ Imagine an
Oracle installation and a SAP installation on the same NUMA box fighting
over the 'optimal' setting for this flag. What will they do? Will they
try to set the flag to their own preferred value every second or so? ]

Secondly, it was added based on a single datapoint from Martin:

 http://marc.theaimsgroup.com/?l=linux-mm&m=111763597218177&w=2

where Martin characterizes the numbers the following way:

 ' Run-to-run variability for "make -j" is huge, so these numbers aren't
   terribly useful except to see that with reclaim the benchmark still
   finishes in a reasonable amount of time. '

in other words: the fundamental problem has likely not been solved, only
a tendential move into the right direction has been observed, and a
handful of numbers were picked out of a set of hugely variable results,
without showing the variability data. How much variance is there
run-to-run?

I'd really suggest to first walk the walk and see what's needed to get
stable & predictable kernel compilation numbers on that NUMA box, before
adding random syscalls to tune a particular aspect of the VM ... which
approach might not even matter once the whole picture has been analyzed
and understood!

The third, most important point is that the syscall exposes VM tuning
internals in a completely unstructured way. What sense does it make to
have a _GLOBAL_ per-node setting for 'should we go to another node for
reclaim'? If then it might make sense to do this per-app, via numalib or
so.

The change is minimalistic in that it doesnt remove the syscall and the
underlying infrastructure changes, only the user-visible changes.  We
could perhaps add a CAP_SYS_ADMIN-only sysctl for this hack, a'ka
/proc/sys/vm/swappiness, but even that looks quite counterproductive
when the generic approach is that we are trying to reduce the number of
external factors in the VM balance picture.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-01 10:03:56 -07:00
..
acpi-ext.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
acpi.c [ACPI] merge acpi-2.6.12 branch into latest Linux 2.6.13-rc... 2005-07-12 17:21:56 -04:00
asm-offsets.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
brl_emu.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
cyclone.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
domain.c [PATCH] Dynamic sched domains: ia64 changes 2005-06-25 16:24:45 -07:00
efi.c [PATCH] ia64 uncached alloc 2005-06-21 18:46:18 -07:00
efi_stub.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
entry.h [IA64] Drop spurious paren in entry.h 2005-06-20 09:34:02 -07:00
entry.S [PATCH] remove sys_set_zone_reclaim() 2005-08-01 10:03:56 -07:00
fsys.S Auto merge with /home/aegl/GIT/linus 2005-06-15 14:06:48 -07:00
gate-data.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
gate.lds.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
gate.S [IA64] need r29=psr *after* rsm psr.i 2005-04-27 21:22:40 -07:00
head.S [IA64] Fix build errors for !HOTPLUG case. 2005-04-22 14:46:24 -07:00
ia64_ksyms.c [IA64] __ia64_syscall() is no longer used anywhere in the kernel. Remove it. 2005-04-27 21:10:45 -07:00
init_task.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
iosapic.c [IA64] assign_irq_vector() should not panic 2005-07-11 10:30:07 -07:00
irq.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
irq_ia64.c [IA64] assign_irq_vector() should not panic 2005-07-11 10:30:07 -07:00
irq_lsapic.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
ivt.S [IA64] Speed up lfetch.fault [NULL] 2005-06-28 09:28:16 -07:00
jprobes.S [PATCH] Kprobes/IA64: architecture specific JProbes support 2005-06-23 09:45:22 -07:00
kprobes.c [PATCH] kprobes: fix namespace problem and sparc64 build 2005-07-05 19:19:00 -07:00
machvec.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
Makefile [IA64] fix generic/up builds 2005-07-06 18:18:10 -07:00
mca.c [ACPI] Evaluate CPEI Processor Override flag 2005-07-12 00:01:41 -04:00
mca_asm.S [IA64] cpu hotplug: return offlined cpus to SAL 2005-04-22 14:44:40 -07:00
mca_drv.c [IA64] MCA recovery improvements 2005-05-03 13:47:42 -07:00
mca_drv.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
mca_drv_asm.S [IA64] MCA recovery improvements 2005-05-03 13:47:42 -07:00
minstate.h [IA64] Fix stack placement when INIT hits in kernel mode. 2005-05-06 10:16:07 -07:00
module.c [IA64] Module gp must point to valid memory 2005-06-08 11:41:31 -07:00
numa.c [IA64] fix generic/up builds 2005-07-06 18:18:10 -07:00
pal.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
palinfo.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
patch.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon.c [IA64] remove linux/version.h include from arch/ia64 2005-07-11 09:58:52 -07:00
perfmon_default_smpl.c [IA64] perfmon: make pfm_sysctl a global, and other cleanup 2005-04-25 13:08:30 -07:00
perfmon_generic.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon_itanium.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
perfmon_mckinley.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
process.c [PATCH] Don't export machine_restart, machine_halt, or machine_power_off. 2005-07-26 14:35:42 -07:00
ptrace.c Auto merge with /home/aegl/GIT/ia64-test 2005-06-28 08:24:49 -07:00
sal.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
salinfo.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
semaphore.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
setup.c Auto merge with /home/aegl/GIT/linus 2005-07-13 12:15:43 -07:00
sigframe.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.c [IA64] restore_sigcontext is not preempt safe 2005-07-06 15:31:15 -07:00
smp.c [IA64] Fix another IA64 preemption problem 2005-06-28 10:01:19 -07:00
smpboot.c [IA64] fix generic/up builds 2005-07-06 18:18:10 -07:00
sys_ia64.c [IA64] sys_mmap doesn't follow posix.1 when parameter len=0 2005-05-26 10:19:07 -07:00
time.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
topology.c [IA64] Fix undefined reference to can_cpei_retarget for simulator 2005-07-14 09:21:47 -07:00
traps.c [IA64] Make ia64 die() preempt safe 2005-07-06 15:44:55 -07:00
unaligned.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
uncached.c [PATCH] ia64 uncached alloc 2005-06-21 18:46:18 -07:00
unwind.c [IA64] unwind.c uses wrong unat from switch_stack 2005-07-27 14:18:08 -07:00
unwind_decoder.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
unwind_i.h Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vmlinux.lds.S [PATCH] kprobes/ia64: refuse kprobe on ivt code 2005-06-27 15:23:54 -07:00