Operating Systems – Is Swapping Enabled by Default?

Sorry for this late answer. I faced this problem yesterday while installing Linux mint. Here is what you need to do

1. In the bios setup(you get here by hitting f10 on my system just after switching the power button), as you have disabled the secure boot option( if you have not, then do it) go to the UEFI boot order options, select Windows boot manager(or something similar, I dont remember the name), press enter to open the sub menus

2. Change to order of your boot loader keeping on top the Linux one( you can do this by pressing f5/f6). Save this by pressing f10. Ensure that the order is correctly saved by entering the sub menu once more

3. Now save and exit the bios setup. That should do the trick. I again apologize for this late answer as this was my first dual boot and the very first problem I faced was this.

Good Luck.

@Stephen_Kitt reports that "Debian 6 was current in 2011, with kernel 2.6.32, and didn’t have transparent hugepages, it had hugetlbfs. Debian used “madvise” from 2.6.38 to 4.13, where it switched to “always”. Thus Debian 7 through 9 use “madvise”, while Debian 10 will use “always”."

Some installs of Ubuntu on servers are reported as enabling hugepages for all apps. (That is, web search finds some users asking how to disable huge pages on their Ubuntu installs :-). ). Some of these mention EC2 images specifically. @couling reports their Ubuntu server on AWS does not enable hugepages for all apps. So it seemed a bit difficult to answer for Ubuntu Server. Then I found the AskUbuntu question, "Where can I get the [Ubuntu] 11.04 kernel .config file?".

In Ubuntu 16.04, specific builds are available e.g. for AWS (Amazon Web Services). Looking at kernel version 4.4.0-125.150, the AWS kernel enabled TRANSPARENT_HUGEPAGES_ALWAYS. However the generic kernel did not.

In Ubuntu 18.04, the generic kernel still did not enable TRANSPARENT_HUGEPAGES_ALWAYS.

Ubuntu 11.10 was released in October 2011, and might be the first release with TRANSPARENT_HUGEPAGES enabled. It appears to not enable TRANSPARENT_HUGEPAGES_ALWAYS.

I think current SLES - SUSE Linux Enterprise version 15, and at least versions 12 and 11 - also match the current RHEL setting. I.e. they enable transparent hugepages for all apps.

[By implication: was LWN.net correct here, or not?]

All three of the bug reports cited by kernel developer Mel Gorman, involved a web browser affected when copying to a slow USB stick or SD card. So that point of the article is well-founded. One of the reports was "internally in SUSE". In the other two cases, it is not immediately clear where the kernel configuration came from.

As @couling pointed out, if the sysfs file shows [madvise], you should not say that THP is disabled altogether. It only means that THP will not applied automatically for all apps, as in the [always] case. At least to some extent, the LWN article glossed over the distinction - the distinction between "the transparent huge pages feature is built into the kernel", and "the page fault handler will attempt to allocate a huge page", regarding a web browser which is known not to use MADV_HUGEPAGE. It is clear that most distributors enable the former, but the latter claim is not so clear to me.

I notice that according to the source code, when you choose to enable the kernel config TRANSPARENT_HUGEPAGE, the default config is (and has always been) to enable TRANSPARENT_HUGEPAGE_ALWAYS.

Perhaps LWN mis-interpreted this. Or perhaps there was a brief surge of distribution kernels released with TRANSPARENT_HUGEPAGE_ALWAYS, which were then reverted after discovering the range of potential disadvantages :-). I am not sure.