| Message ID | 20220609185024.447922-3-mathieu.desnoyers@efficios.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Thu, Jun 9, 2022 at 2:50 PM Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote: > > The current implementation of the 20_linux_xen script implements its > menu items sorting in bash with a quadratic algorithm, calling "sed", > "sort", "head", and "grep" to compare versions between individual lines, > which is annoyingly slow for kernel developers who can easily end up > with 50-100 kernels in their boot partition. > > This fix is ported from the 10_linux script, which has a similar > quadratic code pattern. > > [ Note: this is untested. I would be grateful if anyone with a Xen > environment could test it before it is merged. ] Hi, Mathieu, I tested by manually applying patch 2/5 on top of Fedora 36's installed /etc/grub.d/20_linux_xen, and manually applying patch 1/5 to /usr/share/grub/grub-mkconfig_lib. It seems to generate grub.cfg menuentry-ies in the correct order. Note for patch 1/5, it's best practice to use "$@" with the double quotes to prevent word splitting of arguments. Doesn't really matter for that function at this time though. Regards, Jason
----- On Jun 10, 2022, at 4:00 PM, Jason Andryuk jandryuk@gmail.com wrote: > On Thu, Jun 9, 2022 at 2:50 PM Mathieu Desnoyers > <mathieu.desnoyers@efficios.com> wrote: >> >> The current implementation of the 20_linux_xen script implements its >> menu items sorting in bash with a quadratic algorithm, calling "sed", >> "sort", "head", and "grep" to compare versions between individual lines, >> which is annoyingly slow for kernel developers who can easily end up >> with 50-100 kernels in their boot partition. >> >> This fix is ported from the 10_linux script, which has a similar >> quadratic code pattern. >> >> [ Note: this is untested. I would be grateful if anyone with a Xen >> environment could test it before it is merged. ] > > Hi, Mathieu, > > I tested by manually applying patch 2/5 on top of Fedora 36's > installed /etc/grub.d/20_linux_xen, and manually applying patch 1/5 to > /usr/share/grub/grub-mkconfig_lib. It seems to generate grub.cfg > menuentry-ies in the correct order. Noted. Added your Tested-by to patch 2/5. Thanks! > > Note for patch 1/5, it's best practice to use "$@" with the double > quotes to prevent word splitting of arguments. Doesn't really matter > for that function at this time though. I'll update patch 1/5 with this change. It's best practice indeed. I notice that there are quite a few other places in grub-mkconfig_lib.in that do follow this best practice though. Thanks, Mathieu > > Regards, > Jason
diff --git a/util/grub.d/20_linux_xen.in b/util/grub.d/20_linux_xen.in index 51a983926..4382303c1 100644 --- a/util/grub.d/20_linux_xen.in +++ b/util/grub.d/20_linux_xen.in @@ -237,11 +237,17 @@ esac # yet, so it's empty. In a submenu it will be equal to '\t' (one tab). submenu_indentation="" +# Perform a reverse version sort on the entire xen_list and linux_list. +# Temporarily replace the '.old' suffix by ' 1' and append ' 2' for all +# other files to order the '.old' files after their non-old counterpart +# in reverse-sorted order. + +reverse_sorted_xen_list=$(echo ${xen_list} | tr ' ' '\n' | sed -e 's/\.old$/ 1/; / 1$/! s/$/ 2/' | version_sort -r | sed -e 's/ 1$/.old/; s/ 2$//') +reverse_sorted_linux_list=$(echo ${linux_list} | tr ' ' '\n' | sed -e 's/\.old$/ 1/; / 1$/! s/$/ 2/' | version_sort -r | sed -e 's/ 1$/.old/; s/ 2$//') + is_top_level=true -while [ "x${xen_list}" != "x" ] ; do - list="${linux_list}" - current_xen=`version_find_latest $xen_list` +for current_xen in ${reverse_sorted_xen_list}; do xen_basename=`basename ${current_xen}` xen_dirname=`dirname ${current_xen}` rel_xen_dirname=`make_system_path_relative_to_its_root $xen_dirname` @@ -273,8 +279,7 @@ while [ "x${xen_list}" != "x" ] ; do fi done - while [ "x$list" != "x" ] ; do - linux=`version_find_latest $list` + for linux in ${reverse_sorted_linux_list}; do gettext_printf "Found linux image: %s\n" "$linux" >&2 basename=`basename $linux` dirname=`dirname $linux` @@ -351,13 +356,10 @@ while [ "x${xen_list}" != "x" ] ; do linux_entry "${OS}" "${version}" "${xen_version}" recovery \ "${GRUB_CMDLINE_LINUX_RECOVERY} ${GRUB_CMDLINE_LINUX}" "${GRUB_CMDLINE_XEN}" fi - - list=`echo $list | tr ' ' '\n' | fgrep -vx "$linux" | tr '\n' ' '` done if [ x"$is_top_level" != xtrue ]; then echo ' }' fi - xen_list=`echo $xen_list | tr ' ' '\n' | fgrep -vx "$current_xen" | tr '\n' ' '` done # If at least one kernel was found, then we need to
The current implementation of the 20_linux_xen script implements its menu items sorting in bash with a quadratic algorithm, calling "sed", "sort", "head", and "grep" to compare versions between individual lines, which is annoyingly slow for kernel developers who can easily end up with 50-100 kernels in their boot partition. This fix is ported from the 10_linux script, which has a similar quadratic code pattern. [ Note: this is untested. I would be grateful if anyone with a Xen environment could test it before it is merged. ] Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: xen-devel@lists.xenproject.org --- Changes since v4: - Combine sed -e '...' -e '...' into sed -e '...; ...' --- util/grub.d/20_linux_xen.in | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)