Moves the option that instructs Node.js to-remap its static code to
large pages from a configure-time option to a runtime option. This
should make it easy to assess the performance impact of such a change
without having to custom-build.

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#30954
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Co-authored-by: David Carlier <devnexen@gmail.com>

Re-introduce the build-time option as a no-op in order to retain
backward compatibility for LTS purposes.

Backport-PR-URL: nodejs#32092
Re: nodejs#31063 (review)
PR_URL: nodejs#31075
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#31095
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

The usage of the relevant methods from the file is conditional so make
the include conditional too.

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#31078
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Emit a warning when the user configures with `--use-largepages` and/or
`--use-largepages-script-lld` informing them that the option is now
available as a Node.js runtime option once it is built.

Backport-PR-URL: nodejs#32092
Refs: nodejs#31063 (comment)
PR-URL: nodejs#31103
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

`__executable_start` is provided by GNU's and LLVM's default linker
scripts, obviating the need to plug in a custom linker script.

The problem with our bespoke linker script is that it works with ld.bfd
but not ld.gold and cannot easily be ported because the latter linker
doesn't understand the `INSERT BEFORE` directive.

The /proc/self/maps scanner is updated to account for the fact that
there are a number of sections between `&__executable_start` and
the start of the .text section.

Fortunately, those sections are all mapped into the same memory segment
so we only need to look at the next line to find the start of our text
segment.

Fixes: nodejs#31520

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#31547
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>

Restrict the usage of the C preprocessor directive enabling large
pages support to the large pages implementation. This cleans up the
code in src/node.cc.

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#31904
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

We create an object file in assembly which introduces the symbol
`__node_text_start` into the .text section and place the resulting
object file as the first file the linker encounters. We do this to
ensure that we can recognize the boundaries of the .text section when
attempting to establish the address range to map to large pages.

Additionally, we rename the section containing the remapping code from
`.lpstub` to `lpstub` so as to take advantage of the linker's feature
whereby it inserts the symbol `__start_lpstub` when the section's name
can be rendered as a valid C variable. We need this symbol in order to
avoid self-mapping the remapping code to large pages, because doing so
would cause the process to crash.

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#31981
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Signed-off-by: Gabriel Schulhof <gabriel.schulhof@intel.com>

The ninja build places objects in a different directory.

Co-authored-by: Gabriel Schulhof <gabriel.schulhof@intel.com>
Signed-off-by: Richard Lau <riclau@uk.ibm.com>

Backport-PR-URL: nodejs#32092
PR-URL: nodejs#32071
Reviewed-By: Matheus Marchini <mat@mmarchini.me>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

Moves the option that instructs Node.js to-remap its static code to
large pages from a configure-time option to a runtime option. This
should make it easy to assess the performance impact of such a change
without having to custom-build.

Backport-PR-URL: #32092
PR-URL: #30954
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Co-authored-by: David Carlier <devnexen@gmail.com>

Re-introduce the build-time option as a no-op in order to retain
backward compatibility for LTS purposes.

Backport-PR-URL: #32092
Re: #31063 (review)
PR_URL: #31075
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Backport-PR-URL: #32092
PR-URL: #31095
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

The usage of the relevant methods from the file is conditional so make
the include conditional too.

Backport-PR-URL: #32092
PR-URL: #31078
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>

Emit a warning when the user configures with `--use-largepages` and/or
`--use-largepages-script-lld` informing them that the option is now
available as a Node.js runtime option once it is built.

Backport-PR-URL: #32092
Refs: #31063 (comment)
PR-URL: #31103
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

`__executable_start` is provided by GNU's and LLVM's default linker
scripts, obviating the need to plug in a custom linker script.

The problem with our bespoke linker script is that it works with ld.bfd
but not ld.gold and cannot easily be ported because the latter linker
doesn't understand the `INSERT BEFORE` directive.

The /proc/self/maps scanner is updated to account for the fact that
there are a number of sections between `&__executable_start` and
the start of the .text section.

Fortunately, those sections are all mapped into the same memory segment
so we only need to look at the next line to find the start of our text
segment.

Fixes: #31520

Backport-PR-URL: #32092
PR-URL: #31547
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>

Restrict the usage of the C preprocessor directive enabling large
pages support to the large pages implementation. This cleans up the
code in src/node.cc.

Backport-PR-URL: #32092
PR-URL: #31904
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

We create an object file in assembly which introduces the symbol
`__node_text_start` into the .text section and place the resulting
object file as the first file the linker encounters. We do this to
ensure that we can recognize the boundaries of the .text section when
attempting to establish the address range to map to large pages.

Additionally, we rename the section containing the remapping code from
`.lpstub` to `lpstub` so as to take advantage of the linker's feature
whereby it inserts the symbol `__start_lpstub` when the section's name
can be rendered as a valid C variable. We need this symbol in order to
avoid self-mapping the remapping code to large pages, because doing so
would cause the process to crash.

Backport-PR-URL: #32092
PR-URL: #31981
Reviewed-By: Franziska Hinkelmann <franziska.hinkelmann@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Signed-off-by: Gabriel Schulhof <gabriel.schulhof@intel.com>

The ninja build places objects in a different directory.

Co-authored-by: Gabriel Schulhof <gabriel.schulhof@intel.com>
Signed-off-by: Richard Lau <riclau@uk.ibm.com>

Backport-PR-URL: #32092
PR-URL: #32071
Reviewed-By: Matheus Marchini <mat@mmarchini.me>
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: Shelley Vohr <codebytere@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>