Use a ring-buffer like multi-version object structure which allows
always having a coherent object; we use this to avoid having to
disable IRQs while reading sched_clock() and avoids a problem when
getting an NMI while changing the cyc2ns data.
MAINLINE PRE POST
sched_clock_stable: 1 1 1
(cold) sched_clock: 329841 331312 257223
(cold) local_clock: 301773 310296 309889
(warm) sched_clock: 38375 38247 25280
(warm) local_clock: 100371 102713 85268
(warm) rdtsc: 27340 27289 24247
sched_clock_stable: 0 0 0
(cold) sched_clock: 382634 372706 301224
(cold) local_clock: 396890 399275 399870
(warm) sched_clock: 38194 38124 25630
(warm) local_clock: 143452 148698 129629
(warm) rdtsc: 27345 27365 24307
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-s567in1e5ekq2nlyhn8f987r@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SGI UV tlb shootdown code panics the system with a NULL
pointer deference if 'nobau' is specified on the boot
commandline.
uv_flush_tlb_other() gets called for every flush, whether the
BAU is disabled or not. It should not be keeping the s_enters
statistic while the BAU is disabled.
The panic occurs because during initialization
init_per_cpu_tunables() does not set the bcp->statp pointer if
'nobau' was specified.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@vger.kernel.org> # 3.12.x
Link: http://lkml.kernel.org/r/E1VnzBi-0005yF-MU@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 cleanup patches from Ingo Molnar:
"Misc smaller cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: ptrace.c only needs export.h and not the full module.h
x86, apb_timer: remove unused variable percpu_timer
um: don't compare a pointer to 0
arch/x86/platform/uv: use ARRAY_SIZE where possible
The flush tlb optimization code has logical issue on UV
platform. It doesn't flush the full range at all, since it
simply ignores its 'end' parameter (and hence also the "all"
indicator) in uv_flush_tlb_others() function.
Cliff's notes:
| I tested the patch on a UV. It has the effect of either
| clearing 1 or all TLBs in a cpu. I added some debugging to
| test for the cases when clearing all TLBs is overkill, and in
| practice it happens very seldom.
Reported-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Tested-by: Cliff Wickman <cpw@sgi.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86/mm changes from Peter Anvin:
"The big change here is the patchset by Alex Shi to use INVLPG to flush
only the affected pages when we only need to flush a small page range.
It also removes the special INVALIDATE_TLB_VECTOR interrupts (32
vectors!) and replace it with an ordinary IPI function call."
Fix up trivial conflicts in arch/x86/include/asm/apic.h (added code next
to changed line)
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/tlb: Fix build warning and crash when building for !SMP
x86/tlb: do flush_tlb_kernel_range by 'invlpg'
x86/tlb: replace INVALIDATE_TLB_VECTOR by CALL_FUNCTION_VECTOR
x86/tlb: enable tlb flush range support for x86
mm/mmu_gather: enable tlb flush range in generic mmu_gather
x86/tlb: add tlb_flushall_shift knob into debugfs
x86/tlb: add tlb_flushall_shift for specific CPU
x86/tlb: fall back to flush all when meet a THP large page
x86/flush_tlb: try flush_tlb_single one by one in flush_tlb_range
x86/tlb_info: get last level TLB entry number of CPU
x86: Add read_mostly declaration/definition to variables from smp.h
x86: Define early read-mostly per-cpu macros
x86 has no flush_tlb_range support in instruction level. Currently the
flush_tlb_range just implemented by flushing all page table. That is not
the best solution for all scenarios. In fact, if we just use 'invlpg' to
flush few lines from TLB, we can get the performance gain from later
remain TLB lines accessing.
But the 'invlpg' instruction costs much of time. Its execution time can
compete with cr3 rewriting, and even a bit more on SNB CPU.
So, on a 512 4KB TLB entries CPU, the balance points is at:
(512 - X) * 100ns(assumed TLB refill cost) =
X(TLB flush entries) * 100ns(assumed invlpg cost)
Here, X is 256, that is 1/2 of 512 entries.
But with the mysterious CPU pre-fetcher and page miss handler Unit, the
assumed TLB refill cost is far lower then 100ns in sequential access. And
2 HT siblings in one core makes the memory access more faster if they are
accessing the same memory. So, in the patch, I just do the change when
the target entries is less than 1/16 of whole active tlb entries.
Actually, I have no data support for the percentage '1/16', so any
suggestions are welcomed.
As to hugetlb, guess due to smaller page table, and smaller active TLB
entries, I didn't see benefit via my benchmark, so no optimizing now.
My micro benchmark show in ideal scenarios, the performance improves 70
percent in reading. And in worst scenario, the reading/writing
performance is similar with unpatched 3.4-rc4 kernel.
Here is the reading data on my 2P * 4cores *HT NHM EP machine, with THP
'always':
multi thread testing, '-t' paramter is thread number:
with patch unpatched 3.4-rc4
./mprotect -t 1 14ns 24ns
./mprotect -t 2 13ns 22ns
./mprotect -t 4 12ns 19ns
./mprotect -t 8 14ns 16ns
./mprotect -t 16 28ns 26ns
./mprotect -t 32 54ns 51ns
./mprotect -t 128 200ns 199ns
Single process with sequencial flushing and memory accessing:
with patch unpatched 3.4-rc4
./mprotect 7ns 11ns
./mprotect -p 4096 -l 8 -n 10240
21ns 21ns
[ hpa: http://lkml.kernel.org/r/1B4B44D9196EFF41AE41FDA404FC0A100BFF94@SHSMSX101.ccr.corp.intel.com
has additional performance numbers. ]
Signed-off-by: Alex Shi <alex.shi@intel.com>
Link: http://lkml.kernel.org/r/1340845344-27557-3-git-send-email-alex.shi@intel.com
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
On SGI's UV2 the BAU (Broadcast Assist Unit) driver can hang
under a heavy load. To cure this:
- Disable the UV2 extended status mode (see UV2_EXT_SHFT), as
this mode changes BAU behavior in more ways then just delivering
an extra bit of status. Revert status to just two meaningful bits,
like UV1.
- Use no IPI-style resets on UV2. Just give up the request for
whatever the reason it failed and let it be accomplished with
the legacy IPI method.
- Use no alternate sending descriptor (the former UV2 workaround
bcp->using_desc and handle_uv2_busy() stuff). Just disable the
use of the BAU for a period of time in favor of the legacy IPI
method when the h/w bug leaves a descriptor busy.
-- new tunable: giveup_limit determines the threshold at which a hub is
so plugged that it should do all requests with the legacy IPI method for a
period of time
-- generalize disable_for_congestion() (renamed disable_for_period()) for
use whenever a hub should avoid using the BAU for a period of time
Also:
- Fix find_another_by_swack(), which is part of the UV2 bug workaround
- Correct and clarify the statistics (new stats s_overipilimit, s_giveuplimit,
s_enters, s_ipifordisabled, s_plugged, s_congested)
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131459.GC31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch enables the BAU to be turned on or off dynamically.
echo "on" > /proc/sgi_uv/ptc_statistics
echo "off" > /proc/sgi_uv/ptc_statistics
The system may be booted with or without the nobau option.
Whether the system currently has the BAU off can be seen in
the /proc file -- normally with the baustats script.
Each cpu will have a 1 in the bauoff field if the BAU was turned
off, so baustats will give a count of cpus that have it off.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131330.GB31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Correct the calculation of a destination timeout period, which
is used to distinguish between a destination timeout and the
situation where all the target software ack resources are full
and a request is returned immediately.
The problem is that integer arithmetic was overflowing, yielding
a very large result.
Without this fix destination timeouts are identified as resource
'plugged' events and an ipi method of resource releasing is
unnecessarily employed.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120622131212.GA31884@sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The SGI Altix UV2 BAU (Broadcast Assist Unit) as used for
tlb-shootdown (selective broadcast mode) always uses UV2
broadcast descriptor format. There is no need to clear the
'legacy' (UV1) mode, because the hardware always uses UV2 mode
for selective broadcast.
But the BIOS uses general broadcast and legacy mode, and the
hardware pays attention to the legacy mode bit for general
broadcast. So the kernel must not clear that mode bit.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/E1SccoO-0002Lh-Cb@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Initialize two spinlocks in tlb_uv.c and also properly define/initialize
the uv_irq_lock.
The lack of explicit initialization seems to be functionally
harmless, but it is diagnosed when these are turned on:
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_LOCKDEP=y
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Cc: Dimitri Sivanich <sivanich@sgi.com>
Link: http://lkml.kernel.org/r/E1RnXd1-0003wU-PM@eag09.americas.sgi.com
[ Added the uv_irq_lock initialization fix by Dimitri Sivanich ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds separate accounting of UV2 message "strong
nack's" in the BAU statistics.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212238.GF5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch moves the ack of the BAU interrupt to the beginning
of the interrupt handler so that there is less possibility of a
lost interrupt and slower response to a shootdown message.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212146.GE5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch removes an unnecessary test for a
no-destination-resources-available condition that looks like a
destination timeout in UV1, but is separately distinguishable in
UV2.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116212050.GD5767@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch implements a workaround for a UV2 hardware bug.
The bug is a non-atomic update of a memory-mapped register. When
hardware message delivery and software message acknowledge occur
simultaneously the pending message acknowledge for the arriving
message may be lost. This causes the sender's message status to
stay busy.
Part of the workaround is to not acknowledge a completed message
until it is verified that no other message is actually using the
resource that is mistakenly recorded in the completed message.
Part of the workaround is to test for long elapsed time in such
a busy condition, then handle it by using a spare sending
descriptor. The stay-busy condition is eventually timed out by
hardware, and then the original sending descriptor can be
re-used. Most of that logic change is in keeping track of the
current descriptor and the state of the spares.
The occurrences of the workaround are added to the BAU
statistics.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211947.GC5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Move the call to enable_timeouts() forward so that
BAU_MISC_CONTROL is initialized before using it in
calculate_destination_timeout().
Fix the calculation of a BAU destination timeout
for UV2 (in calculate_destination_timeout()).
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211848.GB5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Update the use of the Broadcast Assist Unit on SGI Altix UV2 to
the use of native UV2 mode on new hardware (not the legacy mode).
UV2 native mode has a different format for a broadcast message.
We also need quick differentiaton between UV1 and UV2.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20120116211750.GA5767@sgi.com
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is a workaround for a UV2 hub bug that affects the format of system
global addresses.
The GRU API for UV2 was inadvertently broken by a hardware change. The
format of the physical address used for TLB dropins and for addresses used
with instructions running in unmapped mode has changed. This change was
not documented and became apparent only when diags failed running on
system simulators.
For UV1, TLB and GRU instruction physical addresses are identical to
socket physical addresses (although high NASID bits must be OR'ed into the
address).
For UV2, socket physical addresses need to be converted. The NODE portion
of the physical address needs to be shifted so that the low bit is in bit
39 or bit 40, depending on an MMR value.
It is not yet clear if this bug will be fixed in a silicon respin. If it
is fixed, the hub revision will be incremented & the workaround disabled.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Fix a memory leak in init_per_cpu() when the topology check
fails.
The leak should never occur on deployed systems. It would only occur
in an unexpected topology that would make the BAU unuseable as a result.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.981533045@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Remove the large stack-resident cpumask_t from
reset_with_ipi()'s stack by allocating one per uvhub.
Due to the limited size of the stack the potentially huge cpumask_t may
cause stack overrun. We haven't seen it happen yet, but we need to make it
a practice not to push such structures onto the stack.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Link: http://lkml.kernel.org/r/20110621122242.832589130@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Rename 'bau_targ_hubmask' to 'pnmask' for clarity.
The BAU distribution bit mask is indexed by pnode number, not hub or
blade number. This important fact is not clear while the mask is
called a 'hubmask'.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.630995969@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix reset_with_ipi() to look up a cpu for a blade based on the
distribution map being indexed by the potentially sparsely
numbered pnode.
This patch is critical to tlb shootdown on a partitioned UV
system, or one with nonconsecutive blade numbers.
The distribution map bits represent pnodes relative to the partition base
pnode. Previous to this patch it had been assuming bits based on 0-based,
consecutive blade ids.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.497700003@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix for the topology in which there is a socket 1 on a blade
with no socket 0.
Only call make_per_cpu_thp() for present sockets.
We have only seen this fail for internal configurations.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.363757364@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a call by tunables_write() to smp_processor_id() within a
preemptable region.
Call get_cpu()/put_cpu() around the region where the returned
cpu number is actually used, which makes it non-preemptable.
A DEBUG_PREEMPT warning is prevented.
UV does not support cpu hotplug yet, but this is a step toward
that ability as well.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Link: http://lkml.kernel.org/r/20110621122242.086384966@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
SGI UV's uv_tlb.c driver has become rather hard to read, with overly large
functions, non-standard coding style and (way) too long variable, constant
and function names and non-obvious code flow sequences.
This patch improves the readability and maintainability of the driver
significantly, by doing the following strict code cleanups with no side
effects:
- Split long functions into shorter logical functions.
- Shortened some variable and structure member names.
- Added special functions for reads and writes of MMR regs with
very long names.
- Added the 'tunables' table to shortened tunables_write().
- Added the 'stat_description' table to shorten uv_ptc_proc_write().
- Pass fewer 'stat' arguments where it can be derived from the 'bcp'
argument.
- Function definitions consistent on one line, and inline in few (short) cases.
- Moved some small structures and an atomic inline function to the header file.
- Moved some local variables to the blocks where they are used.
- Updated the copyright date.
- Shortened uv_write_global_mmr64() etc. using some aliasing; no
line breaks. Renamed many uv_.. functions that are not exported.
- Aligned structure fields.
[ note that not all structures are aligned the same way though; I'd like
to keep the extensive commenting in some of them. ]
- Shortened some long structure names.
- Standard pass/fail exit from init_per_cpu()
- Vertical alignment for mass initializations.
- More separation between blocks of code.
Tested on a 16-processor Altix UV.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: penberg@kernel.org
Link: http://lkml.kernel.org/r/E1QOw12-0004MN-Lp@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch adds support for a new version of the SGI UV hub
chip. The hub chip is the node controller that connects multiple
blades into a larger coherent SSI.
For the most part, UV2 is compatible with UV1. The majority of
the changes are in the addresses of MMRs and in a few cases, the
contents of MMRs. These changes are the result in changes in the
system topology such as node configuration, processor types,
maximum nodes, physical address sizes, etc.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Link: http://lkml.kernel.org/r/20110511175028.GA18006@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is a fix for the SGI Altix-UV Broadcast Assist Unit code,
which is used for TLB flushing.
Certain hardware configurations (that customers are ordering)
cause nasids (numa address space id's) to be non-consecutive.
Specifically, once you have more than 4 blades in a IRU
(Individual Rack Unit - or 1/2 rack) but less than the maximum
of 16, the nasid numbering becomes non-consecutive. This
currently results in a 'catastrophic error' (CATERR) detected by
the firmware during OS boot. The BAU is generating an 'INTD'
request that is targeting a non-existent nasid value. Such
configurations may also occur when a blade is configured off
because of hardware errors. (There is one UV hub per blade.)
This patch is required to support such configurations.
The problem with the tlb_uv.c code is that is using the
consecutive hub numbers as indices to the BAU distribution bit
map. These are simply the ordinal position of the hub or blade
within its partition. It should be using physical node numbers
(pnodes), which correspond to the physical nasid values. Use of
the hub number only works as long as the nasids in the partition
are consecutive and increase with a stride of 1.
This patch changes the index to be the pnode number, thus
allowing nasids to be non-consecutive.
It also provides a table in local memory for each cpu to
translate target cpu number to target pnode and nasid.
And it improves naming to properly reflect 'node' and 'uvhub'
versus 'nasid'.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/E1QJmxX-0002Mz-Fk@eag09.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Stop including <linux/delay.h> in x86 header files which don't
need it. This will let the compiler complain when this header is
not included by source files when it should, so that
contributors can fix the problem before building on other
architectures starts to fail.
Credits go to Geert for the idea.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <20110325152014.297890ec@endymion.delvare>
[ this also fixes an upstream build bug in drivers/media/rc/ite-cir.c ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The BAU's initialization of the broadcast description header is
lacking the coherence domain (high bits) in the nasid. This
causes a catastrophic system failure when running on a system
with multiple coherence domains.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
LKML-Reference: <E1PxKBB-0005F0-3U@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a hard-coded limit of a maximum of 16 cpu's per socket.
The UV Broadcast Assist Unit code initializes by scanning the
cpu topology of the system and assigning a master cpu for each
socket and UV hub. That scan had an assumption of a limit of 16
cpus per socket. With Westmere we are going over that limit.
The UV hub hardware will allow up to 32.
If the scan finds the system has gone over that limit it returns
an error and we print a warning and fall back to doing TLB
shootdowns without the BAU.
Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: <stable@kernel.org> # .37.x
LKML-Reference: <E1PZol7-0000mM-77@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch for SGI UV systems addresses a problem whereby
interrupt transactions being looped back from a local IOH,
through the hub to a local CPU can (erroneously) conflict with
IO port operations and other transactions.
To workaound this we set a high bit in the APIC IDs used for
interrupts. This bit appears to be ignored by the sockets, but
it avoids the conflict in the hub.
Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
LKML-Reference: <20101116222352.GA8155@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
___
arch/x86/include/asm/uv/uv_hub.h | 4 ++++
arch/x86/include/asm/uv/uv_mmrs.h | 19 ++++++++++++++++++-
arch/x86/kernel/apic/x2apic_uv_x.c | 25 +++++++++++++++++++++++--
arch/x86/platform/uv/tlb_uv.c | 2 +-
arch/x86/platform/uv/uv_time.c | 4 +++-
5 files changed, 49 insertions(+), 5 deletions(-)
The [vk][cmz]alloc(_node) family of functions return void
pointers which it's completely unnecessary/pointless to cast to
other pointer types since that happens implicitly.
This patch removes such casts from arch/x86.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Cc: trivial@kernel.org
Cc: amd64-microcode@amd64.org
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
LKML-Reference: <alpine.LNX.2.00.1011082310220.23697@swampdragon.chaosbits.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
