[pve-devel] [PATCH ceph 3/4 v5] exclude ceph-osd-crimson when running dwz
Kefu Chai
k.chai at proxmox.com
Mon Jan 26 12:13:04 CET 2026
On Sat Jan 24, 2026 at 12:54 PM CST, Kefu Chai wrote:
> On Fri Jan 23, 2026 at 9:03 PM CST, Fabian Grünbichler wrote:
>> On January 23, 2026 8:56 am, Kefu Chai wrote:
>>> The dwz tool tries to deduplicate debug information across binaries,
>>> but it has limits on the number of DWARF DIE (Debug Information Entries)
>>> it can handle. Large C++ binaries especially those using templates
>>> heavilily (like Ceph's crimson components), often exceed these limits.
>>>
>>> When building packages with DWZ enabled, the debian packging fails with:
>>>
>>> ```
>>> dh_dwz: error: Aborting due to earlier error
>>> ```
>>>
>>> So let's make ceph-crimson-osd an exception when running dwz. This
>>> change will not backported to tentacle as tentacle does not build
>>> crimson by default.
>>
>> FWIW, dh_dwz will be dropped from the default sequence in forky/DH-14,
>> so we could also consider nop-ing it entirely (unless that blows up
>> binary sizes too much?).
>>
>
> Thanks for sharing! This information is critical for this change. Will
> we release tentacle along with forky as the base system?
>
> I will compare the package sizes with and without dwz enabled, and get
> back to you over the mailing list. if sizes difference is minimal or
> smallish, I will export DWZ=false to disable it.
>
The following table shows the size comparison of debug packages (dbg) compiled
from ceph 20.2.0-pve1 with and without DWZ compression:
+---------------------------------+--------------+--------------+--------------+------------+
| Package Name | With DMZ (MB) | Without (MB) | Diff (MB) | Ratio |
+=================================+==============+==============+==============+============+
| ceph-base-dbg | 151.0 | 181.7 | +30.7 | 16.89% |
| ceph-common-dbg | 949.5 | 1091.1 | +141.7 | 12.99% |
| ceph-exporter-dbg | 8.3 | 8.6 | +0.3 | 3.94% |
| ceph-fuse-dbg | 14.1 | 15.2 | +1.1 | 7.13% |
| ceph-immutable-object-cache-dbg | 4.7 | 5.3 | +0.5 | 9.86% |
| ceph-mds-dbg | 79.3 | 88.2 | +8.9 | 10.10% |
| ceph-mgr-dbg | 33.8 | 36.8 | +2.9 | 7.99% |
| ceph-mon-dbg | 194.2 | 220.4 | +26.2 | 11.91% |
| ceph-osd-dbg | 3.7 | 3.9 | +0.2 | 4.53% |
| ceph-test-dbg | 1488.9 | 1827.4 | +338.5 | 18.52% |
| cephfs-mirror-dbg | 8.0 | 9.3 | +1.3 | 14.19% |
| libcephfs-daemon-dbg | 0.1 | 0.1 | +0.0 | 2.51% |
| libcephfs-proxy2-dbg | 0.1 | 0.1 | +0.0 | 1.43% |
| libcephfs2-dbg | 12.7 | 13.5 | +0.8 | 6.02% |
| librados2-dbg | 98.4 | 108.4 | +10.0 | 9.22% |
| libradosstriper1-dbg | 7.1 | 7.3 | +0.2 | 2.83% |
| librbd1-dbg | 113.7 | 150.9 | +37.3 | 24.70% |
| librgw2-dbg | 300.4 | 332.9 | +32.5 | 9.75% |
| libsqlite3-mod-ceph-dbg | 2.2 | 2.3 | +0.0 | 1.78% |
| python3-cephfs-dbg | 1.3 | 1.3 | -0.0 | -0.03% |
| python3-rados-dbg | 1.2 | 1.2 | +0.0 | 0.82% |
| python3-rbd-dbg | 2.2 | 2.2 | -0.0 | -0.01% |
| python3-rgw-dbg | 0.6 | 0.6 | +0.0 | 0.17% |
| radosgw-dbg | 584.8 | 646.6 | +61.8 | 9.56% |
| rbd-fuse-dbg | 2.1 | 2.2 | +0.1 | 6.22% |
| rbd-mirror-dbg | 117.5 | 153.7 | +36.2 | 23.56% |
| rbd-nbd-dbg | 3.4 | 3.6 | +0.2 | 4.28% |
+---------------------------------+--------------+--------------+--------------+------------+
| TOTAL | 4183.2 | 4914.8 | +731.5 | 14.88% |
+---------------------------------+--------------+--------------+--------------+------------+
While a 14.88% reduction may seem modest, it translates to over 700 MB saved per
build. Not sure if we care about this overhead though.. Please let me
know what do you think. I will update the patch accordingly.
>>>
>>> Signed-off-by: Kefu Chai <k.chai at proxmox.com>
>>> ---
>>> ...lude-ceph-osd-crimson-from-dwz-compr.patch | 52 +++++++++++++++++++
>>> patches/series | 1 +
>>> 2 files changed, 53 insertions(+)
>>> create mode 100644 patches/0053-debian-rules-exclude-ceph-osd-crimson-from-dwz-compr.patch
>>>
>>> diff --git a/patches/0053-debian-rules-exclude-ceph-osd-crimson-from-dwz-compr.patch b/patches/0053-debian-rules-exclude-ceph-osd-crimson-from-dwz-compr.patch
>>> new file mode 100644
>>> index 00000000000..c5f477adb30
>>> --- /dev/null
>>> +++ b/patches/0053-debian-rules-exclude-ceph-osd-crimson-from-dwz-compr.patch
>>> @@ -0,0 +1,52 @@
>>> +From 126f3623e3c36bf0bd233b01fd452aeec0415d89 Mon Sep 17 00:00:00 2001
>>> +From: Kefu Chai <k.chai at proxmox.com>
>>> +Date: Fri, 23 Jan 2026 15:04:47 +0800
>>> +Subject: [PATCH] debian/rules: exclude ceph-osd-crimson from dwz compression
>>> +
>>> +When building with DWZ enabled, the debian packaging fails with:
>>> +```
>>> + dh_dwz: error: Aborting due to earlier error
>>> +```
>>> +Running the dwz command manually reveals the root cause:
>>> +```
>>> + $ dwz -mdebian/ceph-osd-crimson/usr/lib/debug/.dwz/x86_64-linux-gnu/ceph-osd-crimson.debug \
>>> + -M/usr/lib/debug/.dwz/x86_64-linux-gnu/ceph-osd-crimson.debug -- \
>>> + debian/ceph-osd-crimson/usr/bin/ceph-osd-crimson \
>>> + debian/ceph-osd-crimson/usr/bin/crimson-store-nbd
>>> + dwz: debian/ceph-osd-crimson/usr/bin/ceph-osd-crimson: Too many DIEs, not optimizing
>>> + dwz: Too few files for multifile optimization
>>> +```
>>> +The dwz tool has a limit on the number of DWARF DIEs (Debug Information
>>> +Entries) it can process. The ceph-osd-crimson binary, being a large C++
>>> +executable with extensive template usage, exceeds this limit, causing
>>> +dwz to exit with status 1 and fail the build.
>>> +
>>> +This change excludes only ceph-osd-crimson from dwz processing using
>>> +the -X flag, allowing other binaries in the package to still benefit
>>> +from DWARF compression while avoiding the build failure.
>>> +
>>> +Please note, we always disable DWZ in ceph-build's ceph-dev-pipeline.
>>> +
>>> +Signed-off-by: Kefu Chai <k.chai at proxmox.com>
>>> +---
>>> + debian/rules | 4 ++++
>>> + 1 file changed, 4 insertions(+)
>>> +
>>> +diff --git a/debian/rules b/debian/rules
>>> +index 4d31ffd069f..9082c9c4dd2 100755
>>> +--- a/debian/rules
>>> ++++ b/debian/rules
>>> +@@ -53,6 +53,10 @@ endif
>>> +
>>> + ifeq ($(DWZ), false)
>>> + override_dh_dwz:
>>> ++else
>>> ++override_dh_dwz:
>>> ++ # Exclude ceph-osd-crimson due to excessive debug info (too many DIEs)
>>> ++ dh_dwz -Xceph-osd-crimson
>>> + endif
>>> +
>>> + # for python3-${pkg} packages
>>> +--
>>> +2.47.3
>>> +
>>> diff --git a/patches/series b/patches/series
>>> index 53e0e6b83ca..874bef96aa4 100644
>>> --- a/patches/series
>>> +++ b/patches/series
>>> @@ -50,3 +50,4 @@
>>> 0050-debian-rules-enable-WITH_CRIMSON-when-pkg.ceph.crims.patch
>>> 0051-debian-ceph.spec-fix-ceph-osd-upgrade-conflicts.patch
>>> 0052-cmake-build-static-seastar-for-release-builds.patch
>>> +0053-debian-rules-exclude-ceph-osd-crimson-from-dwz-compr.patch
>>> --
>>> 2.47.3
>>>
>>>
>>>
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>>>
>>>
>>>
>>
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