Wednesday Nov 18, 2009
Gregynog is a Country house near Newtown which was left to the University of Wales. For the last 13 years it has hosted a weekend of interview skills for 2nd Year Computer Science students from Aberystwyth University, of which I have managed to miss 2.
This year Paul Humphreys and myself ran objective setting sessions. A bit like life coaching, but without the 100 quid an hour overhead.
So good luck to those who's objectives included
- Propose to his girl friends (maybe I should have pointed him to the Kepner Tregoe process for decision analysis)
- Eat a baby dolphin
- Stop smoking (not sure what, best not to ask)
- Get an industrial year which involves Android
- Finish their assignment by an appropriate date
- Write code to do xxxxx in C,C++, Haskal, Perl, Python, etc and put to on their blog.
it takes all sorts to make a world. Many of the outcomes could have been tighter and better clarified, but it was an exercise in "How"
Both Paul and I also set out our list of 10 each, so I am off to finish my 2 books I have been reading since March and Paul will have dug manure into his allotment if it ever stops raining.
Friday Nov 06, 2009
I spent the last 2 days at a customer site in the south east of England. On my way home last night I decided to explore a route up a mountain called The Blorenge. I did not take any pictures, though I am sure the view would have been great if it was light. Being Novemeber the 5th, I felt the youff of Abergaveny let me down somewhat with few fireworks going off.
The Blorenge from the north is just over 500 meters of ascent, some of which is up a old mine works incline and some on open hill side. Nearly all of it is steep, so until the top plateau there was little I was able to run. Still a great hill training venue which is quite reasonable to do at night. Indeed, I was quite surprised to see an other set of lights out running who clearly knew an easier/better way down than straight back down the north face. I really missed my Mudclaws for the 1st 100m of descent.
Many thanks to Martin Beal and his blog for the idea. I have passed 100's of time to my shame, but never though of using it as a training ground and an excuse to break the drive home up. So if Martin at the top of end of the sport can do the ascent in 21.5 minutes, those of us at the other end might find 30 minutes a good target. Last night the ascent took about 45 minutes to the plateau, but some of that
was spent reading the route description and looking for the track in the dark.
Wednesday Oct 14, 2009
Spent part of my day off doing 2 reps of Cader Idris getting in just over 6000ft of ascent and 11 miles. Pictures are not great as I used a phone, choosing to leave the camera behind to save weight. The view from the top was hazzy, so did not bother to take any more. Still, very nice morning out for mid October.
Tuesday Oct 13, 2009
12 years ago to the day I turned up 90 minutes late for my 1st day in the OS Group (clearly a lad from the country who underestimated M25 traffic by quite a lot) at Watchmoor Park. So lets play one of those NLP type positive affirmation games listing the 1st 12 things which come into my head about what has been great about the last 12 years at Sun and hence in no particular order
- CS-CTE, the people, the legacy(not just the mid week beers email alias) and its unspoken philosophy for solving hard problems broadly similar to a synthesis of Von Neumann, Buddhism, a curious Jack Russell Terrier and The Rammones. If it was a religion, I would devote my life to it.
- Rob Hulme
- People called Phil, Andrew and Wayne who appeared at 1st meeting to have larger than life minerals, but in reality don't.
- DTrace
- Hyperactive children called White, Nash and Haslam
- ATS/SGRT/SR/Rational Process/KT
- The Melanson and Gardiner show
- The post cuddly OS Group
- Punjabi National Bank
- Being an OS Ambassador before the program was castrated and had it limbs removed.
- UK Academic customers, even the ones who expect you to commit Harakiri for the C compiler being removed from Solaris 2.0
- Work from Home
Looking forward to more of the same, just different as the scale of change steps up a notch or two.
Sunday Oct 11, 2009
Nothing to do with David Lynch's rather strange early 90's TV series, but a short local mixed terrain race in Aberystwyth.
I need to stop doing the Aber Twin Peaks race. Despite the history I ran past without knowing about most of it and the marshaling, organization, en-route support, etc and goody bag all being top notch, at 7 miles and 1000ft, it is probably incompatible to train for and race in events like Highland Fling and the Nant Peris Horseshoe given my own unique combination of natural ability (not) and time to train. My time was about 10 seconds faster than last year at just under 62 minutes. So a year of training and not much progress? What did strike me was that after 5 minutes and a cup of tea I felt like I could have started running again. Last year I was a wreak for the rest of the day.
What I suspect has happened is my VO2 max has remained much the same and the threshold between where the body chooses the form of fuel (Glycogen or fat) has improved. The later not being a significant part of this race as the body typically has over an hours Glycogen store. I am much better at hill climbing and longer distances than I was this time last year.
So you get what you train for and I will continue following my running interest of longer mountain based races, but I think I will start to include a flat speed (all things are relative) session at least once every 2 weeks in my training.
Saturday Oct 10, 2009
I worked on a farm as my summer job while I was at School and University, so I feel just in claiming some agricultural heritage by sweat and toil if not by decent. About once every 3 month I buy a copy of Farmers Weekly to keep some background in what is going on in agriculture.
Buying a copy of Farmers Weekly in mid-Wales has no shame attached to it. I bought a copy titled alone the lines of "Railway Enthusiast" for my 3 year old who is mad about trains. While I did not comment, I felt the need to tell the chap in W H Smiths in Manchester Airport who I had never seen before or will ever see again that it was not for me. Still small man has got my monies worth out of the train mag.
This weeks copy of F. W. has a Opinion article by a Norfolk farmer called David Richardson who comes across as red faced, older version of Ben Goldacre in wellies which is probably a compliment. I suspect he would be quite happy if certain types of politicians were culled from politics.
Sound Science, however, is about evidence and research. It examines all possibilities. For that reason a scientist will never concede any product or process is 100% safe.
They will admit while existing knowledge shows something is 99.999% OK, there is an outside chance something may be discovered that prevents 100% designation.
It is this reluctance towards absolutism that make then vulnerable to criticism by some.
My experience of mid-Wales farmers is a tendency to pick and choose from what science has to offer as it suits them, but that is probably a mirror of the population in general and our training to believe what the media tell us on science without questioning the quality of the copy.
Also in this issue was the Farmers Weekly's Awards 2009. A good example of an exception to David Richardson's wise words where Elin Jones the local A.M. (Welsh Assembly Government Member), and Christianne Glossop, the Welsh Chief Vet, have used a combined science and common sense approach to the very real problem of Bovine TB. There is no single "black and white" right course of action around this subject, but a complex set of tradeoffs and risks. Some may say it is political suicide for Elin won't be able to count on the support of the voting Badger population in Ceredigion any longer.
Back in the equally whacky world of diagnosis of Computer System problems, claiming to be 100% sure of the root cause or fix of a problem is leading indicator for knowing too little about a computer systems ecosystem to make a useful contribution. I think so at least, but am open to evidence which may change my mind on this matter.
Tuesday Oct 06, 2009
Long, long time since I have been in the Arenig range and the Arenig race gave a perfect excuse. Pleased with a time of 1.19:54, it was as fast as I could have managed, with a bit of a sprinting tussle at the end. At 6 miles, it was shorter than I am used to, so found the faster pace of a shorter race a bit of a struggle(you get what you train for), but the running was great and the decent was fast. The last mile along a disused railway line seemed to go on for ages. Pictures in the usual place.
Cracking race, starting in the middle of nowhere. Best soup and cakes of any race west of Offa's Dyke.
After a customer visit yesterday, I took some time out on the drive home for a jog (still tired from Sunday's race) up Moel Famau. Intersected of Offa's Dyke, I think it must have the best view in Wales. To the west Snowdon, Cader Idris, Arenig's, etc and to the east Liverpool, Manchester, Wrexham, etc. OK, so it has the best view to the West in Wales. Caught the sun setting behind Snowdon as I was starting to descend, stunning. Note to self, must remember to carry camera on such adventures. Great training area and a place it would be reasonable to run at night with a head torch.
Wednesday Sep 30, 2009
The Sun Corp User Group meeting yesterday went well. We had a fair turn out, some good questions and I have been asked to do a couple of company specific sessions as follow on.
Sometimes you don't always give the best answer when answering cold. Once you have had a little time to mull it over you think of a possible better answer or an equally valid alternative approach(or you were just wrong the 1st time, it happens sometimes).
To the gentleman with the umount problem which fails every few mounts prior to a backup, I would also make sure the assumption about why
umount is failing with a busy file. If you are getting an error message in the log which points that way, then fine, if not, it would be a good idea
to get the error code of the umount2 system call when it does fail. We could use DTrace, but we could also wrap the umount command inside truss in the script
truss -t umount2 -v umount2 umount /wibble
make sure it is logged. Still think the live dump is the right way to chase this if you can script it right and don't want to sit by the machine for months on end at 2am when the backup kicks off. This is still the wrong answer as ZFS snapshots would allow you to avoid the umount altogether.
To the people concerned about Oracle performance on ZFS, the offer of 30 minutes or so of SharedShell (http://www.sun.com/123) still stands. One question I should of also asked is if the ZFS intent log is split out and on separate fast storage.
On the way home I went for a run near New Rador. Very nice area indeed and great running. I did come across a flag pole with a red flag and some signage which discussed explosives and this being a restricted area. From later discussions with a local this was a test range and people with metal detectors turn up, hoist the flag and dispose of the various bits of scattered ordnance and you really know when they are there.
I am staying to the paths next time. The thought does not appeal of either arriving on a world war 2 morter shell at the pearly gates or
being an minor character in 1 episode of Old Harry's Game who spent eternity debugging Windows and Linux performance issues with the promise of DTrace port always a few days away.
View New Radnor in a larger map
In spite of the possible objective danger, some great running but I am keeping to the paths until the clearance work is complete in 2011.
Sunday Sep 27, 2009
My typical Sunday afternoon training regime has been more along the lines of I have 2 hours, go out and run and lets see where we end up before we (man plus dog) need to turn around. Somewhat more structured this afternoon with 3 reps up Pumlumon from the west. Only about 6 miles in total. The up bits were mostly runnable, the down bits were soft and fast and the flat bits were absent. Each rep included 300m of ascent and descent. Each time I (dog stayed at home today) got to the top the weather was different. Sunny 1st time, spitting rain 2nd time and in cloud with a cold wind the 3rd ascent, all in the space of about an hour.
No pictures or timings as the battery on both the Garmin and the camera were flat, not much forward planning there then.
View Pumlumon from the west route in a larger map
In a quite different setting, on Tuesday I am presenting at the Sun Corporate User Group Breakfast Meeting in the City. More details can be found are here. I doubt porridge will be served, but there is some Coffee, pastry things and DTrace
Monday Sep 21, 2009
I was pondering a number of things on my evening run up Pumlomon last night via a new path which approaches from the West direct to the summit. No photo's as I decided to take a extra thermal in my bum bag rather than a camera which turned out to be a good choice as the sun started to set. The main pondering was if a footballer paid N millions a year had advanced their sport to the same extent as Sara Outen or Jez Bragg.
I listened to Sara Outen interviewed on Radio 2 and it was just very impressive what she had achieved in rowing across the Indian Ocean. It felt disappointing she was having to sell her boat to pay back a loan. So many daft things she could be getting on with which push the limit beyond what has been done before in a small boat with no friends.
I have not met Jez, but we have run in a few of the same races (Jez at the front, me at the other end of the field). 3rd in the Western States is a uncelebrated national success. Maybe thats the difference, real ambition and ability which push at the boundaries of what is possible does not get widely celebrated.
I don't find the calls for reform of bankers pay any more or less compelling than the case for the reform for Footballers pay. Rowing solo across the Indian Ocean has a high level of obvious risk with a very personal set of rewards. I don't see a lot of risk in being a Footballer or a Banker, so the rational for the level of monetary reward escapes me as neither appears to be pushing the boundaries of what is possible and inspiring other people. Maybe that is entertainment for you. No one is going to pay to watch footage of Sara rowing 10 hours+ a day in the middle of the ocean or Jez plodding down a trail which looks the same as the next trail.
Monday Sep 21, 2009
This looks worth a play with.
Sunday Sep 20, 2009
Taken a week to write this up, but a lot has been going on work wise in my little world. 2 years in a row the Pumlumon Challenge got fantastic weather. For those who only visit mid-Wales for this event, it is always like that. Claims of average rainfall in the region of 1760mm are just figures picked from the Internet without any factual basis, hence my year round sun tan (not).
The race is part of the Vasque series of Ultra marathons, most of which are mountain based. I did the race last year for the 1st time and this year have done 2 other races in the series.
Wynne, chief organizer managed the most informal start for a race to date. Without any warning or build up, a very informal "off you go" was quite amusing.
I was still tired from the Nant Peris Horseshoe the week before which probably demonstrates to me I have the Peris my all and a week is not enough to recover at these distances which is stating the obvious.
It was hot, I found after about 10 miles I was more tired than I should have been, so I was about 30 minutes slower than last year. Since the start is about a mile as the Red Kite flies from my house, I know the route quite well which really helped on the decent down Drosgol picking up about 10 minutes by following the secret quad bike tracks.
I enjoyed this year's race a lot more and even stopped to take a few pictures on top of Drogsol. Great event, fine organization(could have done with more water available at the bottom of Hengwm) and really good to see some of the people like Nick who I had meet on other races in the series.
A couple of photo's shows the large number of native flies which were not biting inclined. Visit them now before the Wind Turbines scheduled to be installed around Nant-y-Moch are put in place (I feel one only has the right to pass adverse comments on such things when their loft is fully insulated if you get my drift).
Friday Sep 11, 2009
Sunday Sep 06, 2009
The Nant Peris Horseshoe starts in Llanberis, takes in the summits of Elidir, Y Garn, Glyder Fawr, Lliwedd, Snowdon and Moel Cynghorion. It is considered by many runners to be the hardest fell race in the Welsh calender at 17.5 miles and 8500ft of ascent. If you think different, I would be interested to know what fell race is harder apart from maybe the Welsh 1000m race and the Tryfan Downhill Dash, do add a comment.
I was very pleased indeed to finish in 5 hours and 13 minutes, which was in the region of 1 hour 20 mins faster than last years epic. I had a target time of 5.30, so in general the race went well. The weather was no where near as hot and apart from the rock being slippery, it was really good running weather with a stiff wind and cloud on the tops, but not so much as to make it cold or navigation difficult. It is the 1st race I have run where felt I achieved my potential on the day. The ascents up Snowdon and Moel Cynghorion were very tough(be something wrong if they were not) and it was cheering for the 3 marshals on top of Snowdon to comment that I was in a much better state than last year.
Dilwen, if you read this, it is now one all for the only race that matters series, next year is the decider!
Mike Blake and friends did a excellent job of organization and marshaling getting the combination of freedom, safety and challenge just right. The contribution of the 3 sponsors(Vic Hotel in Llanberis, 1st Hydro and the Snowdon Mountain Railway) makes a huge difference to the race in terms of access to land in the Llanberis slate quarries to run over, getting the 5 gallons of water to the top of Snowdon on the train and the accommodation for the race HQ. This is one aspect that I was not aware of. It did make me and others chuckle that the prize for the 1st man(I think this is right)
was a pair of tickets on the Snowdon Railway to the summit. If you can run that race in 3 hours 12, you do not need the train to get to the submit. Be a nice treat for his grandparents maybe.
Results will end up here and some photos of the race can be found here. This pic
is taken at about a mile or so from the start, hence the rather fresh look, this pic
is take about a mile from the end, hence the general focus on putting one foot in front of the other.
Next race is much closer to home (about a mile as the Kite flies) is the Pumlumon Challenge which is good value at 27 miles and 5500ft which is part of the Ultra Running Championships. 3 of the races in this series in a year is enough for me.
Friday Sep 04, 2009
The UK Corporate Solaris Users Group on Tuesday 29th September has a breakfast meeting where we are going to sprinkle a little DTrace on your cereal.
DTrace was a requested topic at the last meeting, so in keeping with my preferred style of delivery, it will be demo only. Diagnosis and performance analysis is a full contact sport, so best to show it as it really is.
More details can be found are here
Monday Aug 31, 2009
Compared to the last 2 years of mud, it was a relief that the worst the weather did was give a serious threat of drizzle, but backed off before going through with it. The 2 previous years where we spent 3 nights sleeping in a VW Transporter van with 2 children under 5 who spent the day playing in the mud did test the resolve.
The Beautiful Days festival at Escot Park in Devon in now in its 7th year and it has taken me a week to get round to writing it up. The Guardian describe the festival as a family based folk punk hoedown with give a high level flavor. It is a middle sized festival at around 10,000 people with a mix of bands drawn from folk, punk, reggae and rock spanning the last 40 years of music, for example Hawkwind played the same stage and evening as The King Blues. With a couple of stages, you can't see every band and we also spent some time in the kids area. My highlights were
- Hawkwind : 40 years and still delivering the nearest thing to space travel through the medium of guitar based rock. Great laser show and they really deliver a wall of sound. Probably my top act of the weekend aided only by the products of the Otter Brewery which may have put me in a minority.
- The highlight in terms of exposure to new bands was The King Blues which was a folk punk mash up with some punchy lyrics.
- An other highlight of the past for me was The Blockheads. I am proud that the 1st record I bought at the age of 10 was "What a waste" giving me some punk credentials 31 years later.
Really nice balance between remembering Ian Dury and being a current band.
- I have seen the Levellers so many times, that I can't judge if they were better or worse than previous times
or other bands. I enjoyed it and playing the whole of "A Weapon called the Word" panned out well.
- Its hard to say it, but I found The Pogues a partial disappointment. There is something special about Shane MacGowan which still comes out, but he came across as being in a bit of a state(read hell of a state). Still, the Pogues were a band I had wanted to see for a long time and I am please I stayed around.
- Pronghorn, the worlds premier Cow Punk band was good fun. Suspect the are in a Gene pool of one, but still a good act for a open air stage in the afternoon.
- It should not work, but it did. Les Tribute are all dressed in red, mashing up covers of disco, rock, new romantic and every other type of chart hit from the 1980's with serious showmanship and humor. Went down really well. I am curious how they find bands like that.
- I had not heard of Lamb, Gong or the Subhumans, but all were a good way to spent an hour or so.
- I have seen Dreadzone a couple of times and they were on form. Small people really got into the spirit of it during their set.
- Howard Marks was interesting. I disagree with almost everything he says, but he is still good value listen to
- Mitch Benn who does the music bit on Radio 4 "The Now Show" was very good indeed.
- There is a lot of other stuff going on including full contact Morris dancing where they hit each other with 2 inch wooden sticks, various modern sculptures, a golf carts dressed up as a pirate ship and the option of Confession with Nuns who have whips (it would be quite hard to explain).
So, much fun had by the King family once again, made much easier by the weather and we hope to do it again next year.
An assortment of images.
Next race is the Nant Peris Horseshoe on Saturday at 18 miles and 8500ft of ascent where we have something to prove after last year's rather poor showing.
Friday Aug 07, 2009
Tomorrow, I am talking at the UKUUG conference which I am really looking forward to.
Well not actually my talk, but the event itself. I still have a very fond memory of the 1st UKUUG conference I went to in Herriot Watt University in I think 1992 and it influenced all sorts of things down the line including the series of Sun events I termed Mashups held at various UK Universities in the last year. Just technical, no marketing.
Saturday Aug 01, 2009
Chris has been exploring various limits of a lab M8000. Inspired (well, umm, also maybe board on a conf call) by this and prompted by a Twitter update on Google and recursion from Alec (don't recall if I read it first
on his blog or Twitter) got me thinking about how deep you can recurse on a modern system? So wrote some code. The marginally tricky bit was setting up the alternate stack to handle the signal on with sigaltstack.
#include < unistd.h >
#include < stdio.h >
#include < signal.h >
#include < stdlib.h >
#include < sys/resource.h >
#include < sys/mman.h >
static void handler();
static void recurse(void);
static int depth = 0;
int main()
{
struct sigaction act;
struct rlimit rlp;
stack_t ss;
getrlimit(RLIMIT_STACK, &rlp);
printf("RLIMIT_STACK = %u:%u\n", rlp.rlim_cur, rlp.rlim_max);
act.sa_handler = handler;
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
act.sa_flags |= SA_RESETHAND|SA_SIGINFO|SA_ONSTACK;
if (sigaction(SIGSEGV, &act, NULL) < 0) {
perror("sigaction failed");
exit(1);
}
if ((ss.ss_sp = mmap(NULL, SIGSTKSZ, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0)) == MAP_FAILED) {
perror("mmap failed");
exit(1);
}
ss.ss_size = SIGSTKSZ;
ss.ss_flags = 0;
if (sigaltstack(&ss, NULL) < 0) {
perror("sigaltstack failed");
exit(1);
}
recurse();
}
static void recurse(void)
{
depth++;
recurse();
}
void handler(void)
{
printf("depth = %u\n", depth);
exit(0);
}
1st attempt on a Macbook with OSX gave a number of 524030. We then moved to Solaris Nevada 110 running on one of our x86 lab system. Also tried the S10 Sparc stable server. The Sparc numbers are a lot smaller than the x86 numbers. The Sparc numbers are similar on Solaris 10 or Nevada. What a great microbenchmark this would make to base purchases on, how deep can a system recurse with no function arguments passed. Many purchasing decisions have been made on the results of benchmarks of similar relevance to the business problem in hand so lets not dismiss totally. Anyway, back to reality.
On a Solaris 10 Sparc box we get
ebusy(5.10)$ cc -o recurse recurse.c
ebusy(5.10)$ ./recurse
RLIMIT_STACK = 1000000000:1000000000
depth = 10416627
ebusy(5.10)$ cc -m64 -o recurse recurse.c
ebusy(5.10)$ ./recurse
RLIMIT_STACK = 1000000000:1000000000
depth = 5681792
ebusy(5.10)$ uname -a
SunOS ebusy 5.10 Generic_137137-09 sun4u sparc SUNW,Sun-Fire
and on the Nevada x86 lab system we get
exdev(5.11)$ cc -o recurse recurse.c
exdev(5.11)$ ./recurse
RLIMIT_STACK = 2147483647:2147483647
depth = 16812966
exdev(5.11)$ cc -m64 -o recurse recurse.c
exdev(5.11)$ ./recurse
RLIMIT_STACK = 1000000000:1000000000
depth = 62499512
exdev(5.11)$ uname -a
SunOS exdev 5.11 snv_110 i86pc i386 i86pc
I am sure there are some games to play with increasing the hard stack limit or allocating the alternate stack a huge segment of memory and recursing through that as well. However, over 62 million stack frames is adequate for most recursive situations which will complete.
Interesting that compilation with -x02 or higher leads to assembler that does nothing and the code just sits in a loop without ever calling the function below.
exdev(5.11)$ pstack `pgrep recur`
17659: ./recurse
0000000000400f80 recurse ()
exdev(5.11)$
So a few interesting questions that will have to wait for the next conf call where I don't need to pay too much attention.
Friday Jul 31, 2009
A virtual hug of respect to all members of the noble profession on SysAdmin day.
The multitude of skills I needed to develop as a Systems Administrator, even though 15 years ago, are still essential to the job I do today.
When I visit a customer in a crisis, the Systems Administrator is typically the calmest, have the best grasp of the underlying problem and best placed
to bring the various parties involved together.
So go on, hug your systems administrator. A systems administrator is for life not just for the 31st of July.
Wednesday Jul 29, 2009
I was pondering why a large SGA segment was made up of 4M pages rather than 256M pages and decided to experiment.
A simple as can be bit of code to create an ism segment
#include < sys/types.h >
#include < sys/ipc.h >
#include < sys/shm.h >
#include < stdlib.h >
#include < unistd.h >
#include < stdio.h >
int main(int argc, char **argv)
{
int sz;
int sid;
void *a;
sz = atoi(argv[1]);
if ((sid = shmget(getpid(), sz * (1024 * 1024), IPC_CREAT)) == -1)
{
perror("shmget failed");
exit(1);
}
if ((a = shmat(sid, (void *)0, SHM_SHARE_MMU)) == -1)
{
perror("shmat failed");
exit(1);
}
sleep(60);
}
In a system with UltraSparc VI+ cpu's (panther) I found by default asking for a 1G ISM segment, we were still producing 4M pages according to pmap -xs. A little bit of kernel code reading and we found the decision is made in map_pgszism which looks like this
map_pgszism(caddr_t addr, size_t len)
591 {
592 uint_t szc;
593 size_t pgsz;
594
595 for (szc = mmu_page_sizes - 1; szc >= TTE4M; szc--) {
596 if (disable_ism_large_pages & (1 << szc))
597 continue;
598
599 pgsz = hw_page_array[szc].hp_size;
600 if ((len >= pgsz) && IS_P2ALIGNED(addr, pgsz))
601 return (pgsz);
602 }
603
604 return (DEFAULT_ISM_PAGESIZE);
605 }
606
A little poking around with mdb shows the value of
disable_ism_large_pages to be 0x36. In the common code it is set to 0x2, so must be some platform specific code resetting this value. Poking disable_ism_large_pages to 0x2 with mdb meant the pages for the ISM segment were now 256M in size as reported by pmap. No recommended as a spur of the moment action for your production E25K running Oracle.
disable_ism_large_pages gets set in hat_init_pagesize as an or of disable_large_pages which is set to a shifting and bitmasking perturbation of mmu_exported_pagesize_mask. So a few more hops leads to bugid 6313025 which describes why 32M and 256M pages were turned off for the Panther cpu. Executing application code from the larger (>4M) pages caused nasty thing to happen. The bug is dated 2005 and I had a very distant memory of it, but it was worth tracking down the specifics.
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Good luck with your objectives.