Usb Disk 2.0 Pmap

[Astryd Boschee]

Theres 128kB that aren't in RAM (that'd be Rss), aren't in swap (that's zero, plus it's disabled on this machine) and aren't left on disk as a named file (this segment doesn't mmap a file). So what are they?

They are not mapped to any device and they are not resident in memory, so they can only be purely virtual. They exhibit the kernel having assigned virtual memory to the process that is not (yet) associated with any actual storage. This is a thing that happens.

I was trying to understand the behaviour of pmap and how vectors are updated inside of a generic function call. I wanted to know if new variables were being constantly created in pmap and whether this was truly efficient or if I should be using this differently.

In your example, by passing X to pmap, you are copying (actually, serializing and deserializing) each vector in X to its respective remote process, doing the work, and then the return function acts to copy the vector back. pmap collects the returned values into a list.

Do you have any thoughts on what it would mean to write the data to disk, load it onto each thread with something like Serialization, use it, and then put it back on the hard disk? In my full application, I unfortunately need to create the vector on the main thread before using it on the parallel threads, so I can not avoid the copy.

I've observed the same behavior using both plan(multisession, workers = availableCores()) called from RStudio and using plan(multicore) and calling from an R session running in the terminal. I've also tried reducing the number of workers from 32 to 8 with no luck.

Examining htop it looks like something isn't working correctly with the cores. This screenshot was taken when I set plan (multisession, workers = 8), but you can see activity on all 32 cores. You can also see that in addition to the 8 main sessions of R there many other R sessions that are also occurring. I'm wondering if something is causing extra sessions to spin up and not close down that is bogging down the whole system over time.

Screenshot from 2021-09-22 21-57-2912451055 327 KB

The full code is available here, I haven't had luck creating a minimal reproducible example of the code. But, given that it works fine on mac and windows I don't think the modelling code is the problem.

I think the problem is with furrr creating additional r sessions that aren't closing down. I just looked at htop again several minutes after closing RStudio and it shows heavy activity on all 32 cores, with rsessions still running. Any suggestions?

I think the problem is with furrr creating additional r sessions that aren't closing down. I just looked at htop again several minutes after closing RStudio and it shows heavy activity on all 32 cores, with rsessions still running.

However, what it cannot protect against is when you use futures to parallelize some code, and that code itself uses a non-future parallelization method to parallelize, e.g. hardcoded mclapply(..., mc.cores = detectCores()) or similar. This can also happen when there is C/C++/Fortran code that runs in so called multi-threaded code. So, if there's indeed nested parallelism going on, I suspect this types of reasons.

FWIW, the "red" load in your htop screenshot represents kernel load. In other words, the Linux kernel is really busy trying to catch up with very low-level tasks. This can for instance happens if there is a lot of disk I/O going on.

You might be interested to know when I dual booted the same hardware into windows 10 the code executed very quickly and without issue. There seems to be something specifically going on in Ubuntu. In both cases I was running identical code on fresh R (and Ubuntu/Windows) installs.

I put together some benchmarking code which you can see here if this is of further interest to you: . The upshot is that all of the synthetic control methods, except the very simplest, ran substantially slower on ubuntu than windows 10.

There are two ways to parallelise. Fork and socket.

Linux can support both, Windows only socket. My guess is that your custom function involves a function that had a mode where if it can fork then it does its own parallelization, but when it can't it doesn't. This would explain the apparent behaviour of nested parallelism in Linux but normal parallelism on Windows

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Hi! What do you get when you access the cache_files attribute of your dataset? map with multiprocessing can be an issue for in-memory datasets due to data being copied to the subprocesses (more info).

Datasets are memory mapped from disk, so accessing slices of data counts as adding them to RSS memory. Though it will not fill your physical memory since it pages out the slices of data as soon as any other process requires some memory. Therefore your RSS memory keeps increasing as you iterate on the dataset, but without OOM because the slices of data that are not used anymore are paged out if your system demands memory for something else.

It seems as if the memory was not release after finish processing. The only workaround for me now is to use with_transform for lazily mapping on the fly instead which cannot be cached to disk and cause a bottleneck to my GPU .

Having a bootable Linux on flash drive is very handly tool for a web developer. When I was about to create one, my TDK 16GB flash drive becomes inaccessible in my Windows 7 file explorer. The Windows explorer detected it and shows "Removable drive (H:)". When I clicked the drive, it prompted me to insert a disk in Drive H: as if it were acting as a CD or DVD drive. I checked it on my "Device Manager" and found my flash drive registered as "USB Disk 30X USB Device". I tried some known fix: uninstalled/re-installed the drive's device driver, re-assigned new Drive letter and nothing worked. I thought of giving it a low level format and in this article will show how to do it. Disclaimer: webfoobar assumes no responsibility for any data loss or permanent damage executing the following tutorial steps (use at your own risk).

Click the "USB Parameters" tab and populate the VID, PID, Vendor Name, Product Name and USB Power Consumption fields. The VID and PID are important others can be anything (the USB Power Consumption can be found when ChipGenius display the detailed information of the flash drive earlier). Click "OK" button:

@Tony you must have downloaded a software that is not compatible with your flash drive (the software can recognize your flashdrive but its program isn't built for your flash drive brand/model). Kindly follow the steps 3 and 4 above carefully.

CUANDO YA PENSABA QUE IBA A VOTAR MI USB, DESPUES DE DOS DIAS NAVEGANDO EN INTERNET, INSTALANDO PROGRAMAS Y CACHARREANDO, ME ENCONTRE CON ESTE POST, BAJE ESTE MISMO SOFTWARE QUE USASTE Y ME SIRVIO PERFECTAMENTE.

MUCHAS GRACIAS

I watched a video and than read your article, both shown the same method, I could find a solution entering my USB's VID and PID information in Flashboot.ru but in the utils column, it shows "Firmware" which after a lot of searching on Google, I don't know what it is and where to find this kind of util. Please help me.

I haven't tried installing Linux on a flash drive yet. If your flash drive become inaccessible because of installing Linux in it, the tutorial above might help fix again your flash drive. Just please follow it carefully.

If I have a flash drive like that,, I will try and error every utility/tool available until I found the util/tool that works. Again - Disclaimer: webfoobar assumes no responsibility for any data loss executing the following tutorial steps (use at your own risk).

Please read step #4. In this case, choose whatever your gut feel tells you (do a trial and error). Again remember as disclaimer webfoobar assumes no responsibility for any data loss or permanent damage (use the suggestion at your own risk).

Refer to step #4. Choose whatever you think will work (do a trial and error). Again remember as disclaimer webfoobar assumes no responsibility for any data loss or permanent damage (use the suggestion at your own risk).

Yes, it might. Or you do trial and error, refer to step #4 and choose another tool whatever you think will work until you find one that the start button works. Please remember as disclaimer webfoobar assumes no responsibility for any data loss or permanent damage (use the suggestion at your own risk).

Than you very much brother. It worked perfectly on Toshiba transmemory 16 Gb flash drive. I tried diskpart and lot of other utilities. When I waS about to throw it away I bumped into your article. You saved my day. Thanks a lot.

Please check again step #4. I suggest, choose whatever you think will work until you find one that works (do a trial and error). Again remember as disclaimer webfoobar assumes no responsibility for any data loss or permanent damage (use the suggestion at your own risk).

You can do a trial and error, select the tool that you think will work until you find one that works. Again remember as disclaimer webfoobar assumes no responsibility for any data loss or permanent damage (use the suggestion at your own risk).

As of this writing, the latest version of Solr is 5.2.1. In this step by step guide we will install that version and integrate it with Drupal 7 Panopoly distro site using Search API module. Actually, Panopoly distro is already shipped with Search API and Search API Solr Search modules. All we need to do is to configure the pre-setup Search API Solr server and index. The good thing about using Search API is that it is already integrated with Views module and we can do unlimited customization with our search results.

As of this writing, Bootstrap Drupal theme only supports LESS. This tutorial will show how to create bootstrap sub-theme supporting SASS and use Grunt to manage our workflow effectively. My operating system is Windows. Therefore, the shell commands, output, etc. that will be shown here are for Windows.

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