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Diffstat (limited to 'nixos/doc/manual/release-notes/rl-1909.xml')
| -rw-r--r-- | nixos/doc/manual/release-notes/rl-1909.xml | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/nixos/doc/manual/release-notes/rl-1909.xml b/nixos/doc/manual/release-notes/rl-1909.xml index e0f71aadaba5..ef23099f4f3d 100644 --- a/nixos/doc/manual/release-notes/rl-1909.xml +++ b/nixos/doc/manual/release-notes/rl-1909.xml @@ -424,6 +424,67 @@ installer after creating <literal>/var/lib/nextcloud</literal>. </para> </listitem> + <listitem> + <para> + There exists now <literal>lib.forEach</literal>, which is like <literal>map</literal>, but with + arguments flipped. When mapping function body spans many lines (or has nested + <literal>map</literal>s), it is often hard to follow which list is modified. + </para> + <para> + Previous solution to this problem was either to use <literal>lib.flip map</literal> + idiom or extract that anonymous mapping function to a named one. Both can still be used + but <literal>lib.forEach</literal> is preferred over <literal>lib.flip map</literal>. + </para> + <para> + The <literal>/etc/sysctl.d/nixos.conf</literal> file containing all the options set via + <link linkend="opt-boot.kernel.sysctl">boot.kernel.sysctl</link> was moved to + <literal>/etc/sysctl.d/60-nixos.conf</literal>, as + <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> + recommends prefixing all filenames in <literal>/etc/sysctl.d</literal> with a + two-digit number and a dash to simplify the ordering of the files. + </para> + </listitem> + <listitem> + <para> + We now install the sysctl snippets shipped with systemd. + <itemizedlist> + <para>This enables:</para> + <listitem> + <para>Loose reverse path filtering</para> + </listitem> + <listitem> + <para>Source route filtering</para> + </listitem> + <listitem> + <para> + <literal>fq_codel</literal> as a packet scheduler (this helps to fight bufferbloat) + </para> + </listitem> + </itemizedlist> + + This also configures the kernel to pass coredumps to <literal>systemd-coredump</literal>. + These sysctl snippets can be found in <literal>/etc/sysctl.d/50-*.conf</literal>, + and overridden via <link linkend="opt-boot.kernel.sysctl">boot.kernel.sysctl</link> + (which will place the parameters in <literal>/etc/sysctl.d/60-nixos.conf</literal>). + </para> + </listitem> + <listitem> + <para> + Coredumps are now acquired by <literal>systemd-coredump</literal> by default. + <literal>systemd-coredump</literal> behaviour can still be modified via + <option>systemd.coredump.extraConfig</option>. + To stick to the old behaviour (having the kernel dump to a file called <literal>core</literal> + in the working directory), without piping it through <literal>systemd-coredump</literal>, set + <option>boot.kernel.sysctl."kernel.core_pattern"</option> to <literal>"core"</literal>. + </para> + </listitem> + <listitem> + <para> + <literal>systemd.packages</literal> option now also supports generators and + shutdown scripts. Old <literal>systemd.generator-packages</literal> option has + been removed. + </para> + </listitem> </itemizedlist> </section> </section> |