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Search - "bad timing"
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https://git.kernel.org/…/ke…/... sure some of you are working on the patches already, if you are then lets connect cause, I am an ardent researcher for the same as of now.
So here it goes:
As soon as kernel page table isolation(KPTI) bug will be out of embargo, Whatsapp and FB will be flooded with over-night kernel "shikhuritee" experts who will share shitty advices non-stop.
1. The bug under embargo is a side channel attack, which exploits the fact that Intel chips come with speculative execution without proper isolation between user pages and kernel pages. Therefore, with careful scheduling and timing attack will reveal some information from kernel pages, while the code is running in user mode.
In easy terms, if you have a VPS, another person with VPS on same physical server may read memory being used by your VPS, which will result in unwanted data leakage. To make the matter worse, a malicious JS from innocent looking webpage might be (might be, because JS does not provide language constructs for such fine grained control; atleast none that I know as of now) able to read kernel pages, and pawn you real hard, real bad.
2. The bug comes from too much reliance on Tomasulo's algorithm for out-of-order instruction scheduling. It is not yet clear whether the bug can be fixed with a microcode update (and if not, Intel has to fix this in silicon itself). As far as I can dig, there is nothing that hints that this bug is fixable in microcode, which makes the matter much worse. Also according to my understanding a microcode update will be too trivial to fix this kind of a hardware bug.
3. A software-only remedy is possible, and that is being implemented by all major OSs (including our lovely Linux) in kernel space. The patch forces Translation Lookaside Buffer to flush if a context switch happens during a syscall (this is what I understand as of now). The benchmarks are suggesting that slowdown will be somewhere between 5%(best case)-30%(worst case).
4. Regarding point 3, syscalls don't matter much. Only thing that matters is how many times syscalls are called. For example, if you are using read() or write() on 8MB buffers, you won't have too much slowdown; but if you are calling same syscalls once per byte, a heavy performance penalty is guaranteed. All processes are which are I/O heavy are going to suffer (hostings and databases are two common examples).
5. The patch can be disabled in Linux by passing argument to kernel during boot; however it is not advised for pretty much obvious reasons.
6. For gamers: this is not going to affect games (because those are not I/O heavy)
Meltdown: "Meltdown" targeted on desktop chips can read kernel memory from L1D cache, Intel is only affected with this variant. Works on only Intel.
Spectre: Spectre is a hardware vulnerability with implementations of branch prediction that affects modern microprocessors with speculative execution, by allowing malicious processes access to the contents of other programs mapped memory. Works on all chips including Intel/ARM/AMD.
For updates refer the kernel tree: https://git.kernel.org/…/ke…/...
For further details and more chit-chats refer: https://lwn.net/SubscriberLink/...
~Cheers~
(Originally written by Adhokshaj Mishra, edited by me. )22 -
Made a bad pun at work. Collegue:
What about I break this beer bottle *points at it*, stick it in your throat and put it up your ass sideways afterwards?
Me: 😅 I'll stop 😅
Sometimes my timing is bad :P13 -
A common scenario strikes again today:
- Blocked on a problem at the end of the day
- Tell my wife I'm headed home
- Inspiration strikes
- time flies by coding in the zone
- realize I'm super late
- run out the door like a crazy person1 -
So I recently had a university project which focuses video game audio. We had to work in groups of 3 students and the task was to create a video game which uses audio as a gameplay mechanic.
Our idea was to create a game where you collect different audio samples which get looped as background music, and you have to select the correct ones to have a nice tune. To make it a bit more challenging we had enemies, guns and grenades plus doors which only open if the correct music is playing.
The guns fire on-beat, and the grenades always explode on the first beat of the next bar.
It was quite challenging to get things synced since even small offsets are noticable.
I wrote some nice code and theoretically it should have worked but for some reason the gun shots and the grenades didn't quite hit the beat of the music.
I tweaked stuff, created workarounds, optimized lot's of code to get execution times down but it still only worked sometimes.
I tweaked more and more only to realize that the timing drifted over time.
At that time I worked 20-30 hours on tweaking and trying to get it perfectly timed.
After recalculating some numbers I realized that all the audio samples are recorded at 135 bpm, but the guys who did the recordings said it was 130bpm.
I asked them if it could be the case that the samples are 135bpm and they said:
"yes, they are at 135 bpm as we told you"
I scrolled back in the telegram conversation only to see that they said 130.
Changing the number to 135 resolved all the problems and all of my workarounds and tweaks weren't needed.
So I worked for nearly 30 hours just because they didn't notice their fault and even when they realized that the timing is off sometimes (which took forever because they never played the game), they didn't even consider that they might have given me the wrong numbers.
This all wouldn't be that bad if both of my teammates had worked for more than 15 hours but they didn't. I did all the hard work and the only single thing they did fucked up my workflow. It fucked up the system I created and it fucked up the gameplay as things got unpredictable. Because of their fucking fault I worked as much as both of them combined IN ADDITION to all the other work I did (built 3 maps, coded everything, created animations, ...)
I love working in teams, but only if the whole team is motivated. Those two fuckers were the exact opposite.
Luckily i found the error so I could fix it, but guess with whom I'll never ever work together again?10 -
I had spent the last year working on a online store power by woocommerce with over 100k products from various suppliers. This online store utilized a custom API that would take the various formats that suppliers offer their inventory in and made them consistent. Now everything was going swimmingly initially, but then I began adding more and more products using a plug-in called WP all import. I reached around 100k products and the site would take up to an entire minute to load sometimes timing out. I got desperate so I installed several caching plugins, but to no avail this did not help me. The site was originally only supposed to take three to four months but ended up taking an entire year. Then, just yesterday I found out what went wrong and why this woocommerce website with all of these optimizations was still taking anywhere from 60 to 90 seconds to load, or just timing out entirely. I had initially thought that I needed a beefier server so I moved it to a high CPU digitalocean VM. While this did help a little bit, the site was still very slow and now I had very high CPU usage RAM usage and high disk IO. I was seriously stumped the Apache process was using a high amount of CPU and IO along with MYSQL as well. It wasn't until I started digging deeper into the database that I actually found out what the issue was. As I was loading the site I would run 'show process list' in the SQL terminal, I began to notice a very significant load time for one of the tables, so I went to go and check it out. What I did was I ran a select all query on that particular table just to see how full it was and SQL returned a error saying that I had exceeded the maximum packet size. So I was like okay what the fuck...
So I exited my SQL and re-entered it this time with a higher packet size. I ran a query that would count how many rows were in this particular table and the number came out to being in the millions. I was surprised, and what's worse is that this table belong to a plugin that I had attempted to use early in the development process to cache the site. The plugin was deactivated but apparently it had left PHP files within the wp content directory outside of the actual plugin directory, so it's still executing scripts even though the plugin itself was disabled. Basically every time I would change anything on the site, it would recache the whole thing, and it didn't delete any old records. So 100k+ products caching on saves with no garbage collection... You do the math, it's gonna be a heavy ass database. Not only that but it was serialized data, so when it did pull this metric shit ton of spaghetti from the database, PHP then had to deserialize it. Hence the high ass CPU load. I had caching enabled on the MySQL end of things so that ate the ram. I was really desperate to get this thing running.
Honest to God the main reason why this website took so long was because the load times made it miserable to work on. I just thought that the hardware that I had the site on was inadequate. I had initially started the development on a small Linux VM which apparently wasn't enough, which is why I moved it to digitalocean which also seemed to not be enough, so from there I moved to a dedicated server which still didn't seem to be enough. I was probably a few more 60-second wait times or timeouts from recommending a server cluster to my client who I know would not be willing to purchase it. The client who I promised this site to have completed in 3 months and has waited a year. Seriously, I would tell people the struggles that I would go through with this particular site and they would just tell me to just drop the site; just take the money, just take the loss. I refused to, this was really the only thing that was kicking my ass. I present myself as this high-and-mighty developer like I'm just really good at what I do but then I have this WordPress site that's just beating the shit out of me for a year. It was a very big learning experience and it was also very humbling as well, it made me realize that I really don't know as much as I think I might. It was evidence that there is still so much more to learn out there, I did learn a lot from that experience especially about optimizing websites the different types of methods to do that particular lonely on the server side and I'll be able to utilize this knowledge in the future.
I guess the moral of the story is, never really give up. Ultimately things might get so bad that you're running on hopes and dreams. Those experiences are generally the most humbling. Now I can finally present the site that I am basically a year late on to the client who will be so happy that I did not give up on the project entirely. I'll have experienced this feeling of pure euphoria, and help the small business significantly grow their revenue. Helping others is very fulfilling for me, even at my own expense.
Anyways, gonna stop ranting. Running out of characters. If you're still here... Ty for reading :')7 -
The story of how I got my dream job.
I was working for a company with a job I got just after graduating university. It was ok, not very exciting tech but I learned a lot by just surrounding myself with professional code monkeys. I was there for about a year when my company bought parts of another company and there was talk about people getting fired. This made me worried since I was the last one to get hired, so I started looking around for other jobs. I received this e-mail from a company saying they were looking for interns, what a coincidence! I adjusted my CV and sent it in.
--A few weeks pass--
It's Friday and I'm at a dinner party, it's 10pm and someone is calling me. I pick up and it's a recruiter from this company. I get very nervous but the alcohol helps me keep my cool, I pass the initial idiot test and they invite me for an interview. Yay!
I go to work on Monday and in a 1-on-1 and I tell my boss about the upcoming interview, he gives me a high-five :)
The interview is approaching and I'm feeling that I'm about to get sick, I refuse to believe this so I start taking a lot of medicine (painkillers, cough medicine etc.). I feel a bit better and thank the gods for medication.
--D-day--
I wake up, put on my nicest clothes and get on the train. I had one hour to spare just in case, which was well needed because the fucking train is late by 30 minutes. I'm still heavily medicated because of my ongoing fever. When I arrive I basically have to run there and somehow I manage to pick up a coffee on the way there which I devour in two seconds. I'm ready for the interview!
Some guy meets me in reception and the first thing he says is "My colleague doesn't speak our language so we'll have to speak english". This is fine, I speak good english but I was not prepared for this so it caught me off-guard and made me even more nervous. We get in and start talking. Things are going OK despite my numbed brain. I try to make eye-contact to make a good impression with the foreign engineer but he keeps staring somewhere which is making me nervous.
We get to the technical part on a whiteboard and this is where my brain decides to stop communicating. I'm presented a simple task which I'm struggling with finishing, and I feel the embarrassment coming over me. "NOOOOO THIS IS MY DREAM JOB, THIS CANNOT BE HAPPENING!" I'm thinking to myself. After making myself look like a complete arsehole for some time we wrap it up and just before I step out the door I say to the engineer "You should checkout my Github page, I have lots of interesting stuff there" and he says "I'll be sure to do that" but I don't believe him.
I leave the office in fury (of myself) and make my way to the train station and even though it's the middle of the day I quickly devour two beers to calm my nerves and make me feel a bit better. I was so damn disappointed in myself, I wasted the opportunity of a lifetime! I go back home to my regular (now shitty) job.
--Two days later--
I get a call from an unknown number. I pick up the phone and it's the same recruiter guy. "So how did you think it went?" he says. "To be honest, I think it went really bad", I replied. "What? Really? Because they loved you, you got the job". (this was an obvious recruiter lie) "... wat, are you sure you called the correct person?" I said and he just laughed. The day after I quit my old job the whole department gets fired - such impeccable timing.
--A few months later--
I finish my internship and they want to keep me. I'm so happy. The engineer that was in the interview works on my team. I ask him "Why did you hire me? You know as well as I do that my interview was horrible". It turns out he _did_ look at my Github profile and that's how he knew I could write code. I also heard later that for my position there was about 2000 applicants and somehow I made the interviews.
I still work there today and I couldn't be happier (Sorry for the long text).3 -
"CTO" here.
Two week ago the CEO informs me that the "investor" want to put me in contact urgently with an external software house to help me with my "bottlenecks".
The investor goes immediately on holiday, so it's not available for explanations. The CEO doesn't know much.
Today I meet the software house CTO and CEO.
They tell me that I should do a transfer of knowledge with them. That they will respect my requirements, my schedule and that they want to help me.
During the meeting the business consultant explains "his" vision. Some new development nobody understand. Not even the CEO. The other cofounder is probably in disagreement but stay silent.
I agree to cooperate with them in due time and with due scope and planning.
It appears they already signed a contract with the investor. The investor is offering to us 40 days of a senior developer, for "free".
The CEO doesn't even know the economical details of the contract and he is surprised that has been signed.He also didn't know that a person will come over for 40 (?) days and that we will have to pay the transfer expenses.
I try to be friendly. I explain to them the issues I need to solve. I say specifically that I need help on certain tasks and that my wish is that nothing "new" will start until we fix some obvious problems.
After leaving, in the evening I receive an email from the software house guy, telling me that next week I MUST allocate a slot for technical transfer and the 2 weeks after for on site training. Like that. He also mention we "agreed" on that which is false. We agreed on me deciding the timing.
We are only 2 developers, at the moment and the other one will be on holiday next week, so I'm trying to get from him a lot of things I don't know because I don't know everything.
I'm not even sure I'll be able to explain how to prepare all the environment.
Worst thing is that I don't know what will be the scope of the project.
I really don't know how to behave.
I wrote back setting my conditions. I have holiday too. I have to prepare "documentation", explanation, etc.
I don't want the "senior dev" coming when I'm not present.
Maybe I was too weak answering and I should have started a fight immediately. Because he actually AGREED to let me decide and after that he set conditions on me immediately.
I don't know.
My stomach is burning, I had a very bad digestion with fever and headache, feel like puking, plus I spent several evening hours fixing the fucking Linux kernel bug.
I want to survive. I don't want to let them oust me in this stupid way. I want to fight.
I know that if I will explode, scream or whatever I will be at fault and I'll accelerate my demise.
When I try to be "diplomatic" actually I end up being weak.
When I try to be assertive I'm in fact rude and hysterical.
I can't think anything else.
This is what burnout looks like.19 -
Monday is the deadline for a big project in my master, I worked together with 11 people for one whole year. Our repository is on a server from university and we use the uni cluster to evaluate our results.
And today the uni spontaneous turns of its electricyty for the weekend to test some fallback systems...2 -
Archlinux.org went down just now for probably not only me. Guess who was in the middle of setting up his system again3
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So today a colleague confessed to an attempt to troll my computer by SSHing into it and playing random songs. Thankfully he did not manage but he would just happen to do it the day we have a security audit.
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So happy about being about to convince management that we needed a large refactor, due to requirements change, and since the code architecture from the beginning had boundaries built before knowing all the requirements...
pulled the shame on us, this is a learning lesson card.. blah blah blah
Also explained we need to implement an RTOS, and make the system event driven... which then a stupid programmer said you mean interrupt driven ... and management lost their minds... ( bad memories of poorly executed interrupts in the past).... had to bring everyone back down to earth.. explained yes it’s interrupt driven, but interrupt driven properly unlike in the past (prior to me)... the fuck didn’t properly prioritize the interrupts and did WAYYY too much in the interrupts.
Explained we will be implementing interrupts along side DMA, and literally no message could be lost in normal execution.. and explained polling the old way along side no RTOS, Wastes power, CPU resources and throws timing off.
Same fucker spoke up and said how the fuck You supposed to do timing, all the timing will be further off... I said wrong, in this system .. unlike yours, this is discreet timing potential and accurate as fuck... unlike your round robin while loop of death.
Anyway they gave me 3 weeks.. and the system out performs, and is more power efficient than the older model.
The interrupting developer, now gives me way more respect...4 -
Biggest interview of my entire life is coming up on Thursday. I really need this to go well - it's more than double my current salary, at a time where I'm really starting to struggle to make ends meet. There's an actual "team", and from my interactions with them over the last four interviews, I think they're cool people. It's still a little unusual, because although there's a team or cohort of seniors that I'd be joining, every senior developer is still somewhat siloed, leading their own juniors. I'd also get to be remote 75% of the time, which I think I've realized is a "must have" benefit.
I don't know if it's coincidental or just bad timing then that I've been having episodes of pretty intense vertigo and panic attacks far more frequently than normal lately - even before I had this interview lined up. I realized recently that I must have some kind of anxiety disorder. I don't know if that's from the military, or just from being fucked up via my own missteps. But I can't keep having these attacks.
Anyone who's willing to share - I don't really have anyone to ask. How do you deal with this type of thing? I went to see a shrink last year, but he just gave me pills that replaced these issues with others.10 -
Why the hell does Google navigation always want to calibrate the phones compass when I just started driving?
Is it programmed like "Oh, didn't expect him to actually drive after he entered his destination, now quick, let me catch up on it now"?3 -
At this point there's a poo poking its nose out my butthole but only a few more minutes and I can finally see the output of this program, finish, go to the loo and then go home.3
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When it's early into the night
When the temperature is just right
When I'm surrounded by silence
And no distraction makes me defiance
When I'm feeling cozy and ready to read papers and program for my thesis
But I ruined the perfect night work genesis
BECAUSE I PROMISED TO GO TO MADAFUCKIN DINNER WITH FRIENDS
DAMNIT! -
Me: HM let's fire up my old pirate game prototype and see if I can do anything with it before sea of thieves comes out and everyone says I'm copying...
*Turns on Xbox and goes to store*
Me: ah fuck! -
I hate this feeling.
Changing stuff with a greamripers scythe around my neck called doubt because the available data isn't too convincing.
Then having to go big or nothing as it is an ecosystem change (e.g. changing the cipher suites of TLS, changing protocol - e.g. HTTP 1.1 to 2) so it needs to be consistent as otherwise fun stuff could happen (fun as in the grim reaper cuts off my neck except a few centimeters and plays "now your head is off, now your head is on" ).
To top it off - just few seconds after the change has happened people coming up in the support channel.
My hands are - mysteriously - not sweaty then. Rather cold.
Lil prayer to the heavens and getting the whiskey bottle...
Opening an ongoing discussion in support channel....
And they're discussing whether the page needs to have an additional arrow for going back to the last page or if the default page navigation is enough.
Constantly using @all so everyone gets pissed off due to being pinged every few seconds in a channel that was meant for emergency support.
Now my hands go from a dark red to a bright red, my nostrils flare out, my adrenaline goes through the roof and I literally wanna murder people....
Those days.
I hate those days.
And I hate the timing of some people...
Like they're deliberately fucking with me without knowing it, like the universe told them explicitly to do so just to fuck with me.
*gooozfraba*
And of course, everything else is fine and running smooth like butter, except that said discussion now goes on in a total flamewar so I get even more pings.
Sucks to be in management.
You have way to many rooms where people can annoy you.
To top it off - after being grumpy and pissed and angry for people just annoying the fuck out of me, I have to mediate.
Yeah. Cause the usual person is on vacancy.
*slowly strangling the whiskey bottle like homer does with bart*
Turns out after 15 mins listening to enraged UX designer vs Frontend Team Lead that UX designer meant a completely different thing - uploaded wrong screenshot, whole discussion was unnecessary.
*Nah. Fuck it. Drinking whiskey*
Reminding everyone what the fucking frigging support channel is meant for and that penis fights aka who got the longest schlong don't belong there....
"Yeah it was a mistake, but it wasn't so bad"
...
You pinged fucking 32 people like it was the end of the world, you ignorant fucktwads.
For over 5 mins.
For fucking frigging nothing except your tiny dicks and shitty egos.
*Second round of whiskey*
Back to work after a wasted half hour.
What says monitoring?
Ah. Everything's working.
At least luck hasn't failed me.
Good server. Brave server.
Then I hear this lil voice in my head: no.
The servers know your personality.
They're afraid. Terrified.
Somehow that thought makes me giggle always...
Childish? Maybe. But it helps on those days.... Funnily enough, remaining 3 hours noone said anything in any chat channel.
"I wonder why, I wonder how...."... *hum* -
me: getting really sick on the last day of vacation
also me: at 4am my brain is wake af trying to solve my programming problems.
bad timing brain! -
The feeling when you’re trying out a new thing as a developer and part of it is to use Google Cloud Platform and halfway through, Google starts vomiting errors and you can’t access any information and you think for a second that you broke Google before realizing that you’re not the only one having issues. #badtiming
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Not really the worst but it happened last week. Our lead Dev reviewed a pull request based on works that have been validated several times.
Suddenly, 5 minutes before leaving to take a plane for the week, he tells me that everything is to be refactored because it has no semantical sense, even if it worked perfectly and could be refactored later.
He told me that the day before the delivery and rewriting and restesting everything that had been done took 2 days, several out of worktime hours and huge stress phases. The delivery had to be delayed twice.
I'm easily stressed and a lot of things went by with bad timing (one other coder who could help me was not present, another had to leave early for his kids etc...)
That refactoring was unnecessary but it gave a bad impression to our client and made feel bad fr something I wasn't responsible for.2 -
Bad (or at least uninformed due to unclear requirements) design decisions lead to somewhat perplexing (and above all, frustrating) problems down the line...
Here I am, wrote a cli client for event bus subscription, and since EC2 is eqv to Docker, had to fix the main function to keep it alive - now the deploy stage on the ci/cd pipeline fails due to startup script timing out. But why tho?
I’m not really sure whether I should’ve designed this differently from the get-go or whether my build and deploy configs don’t match anymore due to recent changes and I should figure out what’s wrong with them... or both.
Bottom line is: I have no idea what I’m doing.9