24edf00fb8
Resolves: https://issues.redhat.com/browse/RHEL-137945 Upstream: kdump-utils Conflict: None commit b43908c20f5a028c60b0096006a26a6e52a01279 Author: Philipp Rudo <prudo@redhat.com> Date: Wed Jan 14 15:54:25 2026 +0100 kdump-lib-initramfs: Fix performance regression in kdump_get_conf_val Rewriting kdump_get_conf_val in Bash lead to a massive performance regression. On my test system starting the kdump service took $ time kdumpctl start real 0m13.134s user 0m8.828s sys 0m7.450s which is ~20 times slower compared to kdump-utils-1.0.59-1.fc44 with $ time kdumpctl start real 0m0.641s user 0m0.208s sys 0m0.538s Looking at the traces shows that this is caused because Bash now has to handle the whole kdump.conf, including the extensive comment at the start, every time kdump_get_conf_val is called. This is done multiple times when starting the kdump service and is often cloaked by other functions, e.g. is_ssh_dump_target() or get_save_path(). To fix the issue remove comments and empty lines in a regex again so that the Bash code only has to handle valid config entries. With this change alone the performance is almost as good as the original version with $ time kdumpctl start real 0m0.780s user 0m0.330s sys 0m0.604s In the long run it would make sense to also reduce the number of calls to kdump_get_conf_val. This patch also fixes the issue that subsequent blanks are replaced by a single space. Usually this is not an issue but there are corner cases, e.g. in printf-like format strings passed as an argument, where the new behaviour is undesirable. Fixes: d81109c ("kdump-lib-initramfs: rewrite kdump_get_conf_val") Signed-off-by: Philipp Rudo <prudo@redhat.com> Signed-off-by: Philipp Rudo <prudo@redhat.com> |
||
|---|---|---|
| .gitignore | ||
| 0001-Strip-surrounding-quotes-from-configuration-values.patch | ||
| 0002-unit-tests-Add-case-for-quoted-configuration-values.patch | ||
| 0003-Allow-kdump.service-to-access-LUKS-volume-keys.patch | ||
| 0004-Restore-SELinux-label-of-crypttab-file.patch | ||
| 0005-Allow-sudo-kdumpctl-for-LUKS-dump-target.patch | ||
| 0006-Revert-Strip-surrounding-quotes-from-configuration-v.patch | ||
| 0007-kdump-lib-initramfs-rewrite-kdump_get_conf_val.patch | ||
| 0008-Add-persisent-device-if-FIPS-is-enabled.patch | ||
| 0009-kdump.sh-Centralize-the-F-suboption-handling.patch | ||
| 0010-kdump.sh-Centralize-the-num-threads-sub-option-handl.patch | ||
| 0011-kdump.sh-Skip-num-threads-when-E-and-F-option-is-pre.patch | ||
| 0012-powerpc-consider-CPU-count-while-calculating-crashke.patch | ||
| 0013-powerpc-Set-nr_cpus-16-for-kdump-kernel.patch | ||
| 0014-kexec-kdump-howto.txt-update-paragraphs-related-to-d.patch | ||
| 0015-kdump-lib-initramfs-Fix-performance-regression-in-kd.patch | ||
| gating.yaml | ||
| kdump-utils.spec | ||
| README.md | ||
| sources | ||
kdump-utils
The kdump-utils package