On 12/4/25 22:57, Andrew Morton wrote:
On Wed, 3 Dec 2025 19:33:56 -0700 Shuah Khan <[email protected]> wrote:
This reverts commit 39231e8d6ba7f794b566fd91ebd88c0834a23b98.
Enabling HAVE_GIGANTIC_FOLIOS broke kernel build and git clone on two
systems. git fetch-pack fails when cloning large repos and make hangs
or errors out of Makefile.build with Error: 139. These failures are
random with git clone failing after fetching 1% of the objects, and
make hangs while compiling random files.
The blow is is one of the git clone failures:
git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
linux_6.19
Cloning into 'linux_6.19'...
remote: Enumerating objects: 11173575, done.
remote: Counting objects: 100% (785/785), done.
remote: Compressing objects: 100% (373/373), done.
remote: Total 11173575 (delta 534), reused 505 (delta 411), pack-reused
11172790 (from 1)
Receiving objects: 100% (11173575/11173575), 3.00 GiB | 7.08 MiB/s, done.
Resolving deltas: 100% (9195212/9195212), done.
fatal: did not receive expected object 0002003e951b5057c16de5a39140abcbf6e44e50
fatal: fetch-pack: invalid index-pack output
39231e8d6ba7 simply shuffles ifdefs and Kconfig items, so I assume it
exposed a pre-existing bug.
Reverting 39231e8d6ba7 will re-hide that bug.
And that isn't a bad thing. If we re-hide the bug in 6.18.x and in
mainline then that relieves the people who are hitting this and it
takes the pressure off David, Mike and yourself to get the underlying
bug fixed in a hurry.
So I think I'll queue this as a hotfix, plan to send it Linuswards in a
couple of days.
Or Linus may choose to apply it directly or to do a local revert of
39231e8d6ba7. But I don't see how a local revert will get communicated
to the 6.18.x maintainers.
David, Linus, opinions please?
I have so far no indication that this patch here would change anything
relevant to the problem we are seeing, all it does is changing
MAX_FOLIO_ORDER that does not affect any logic we would really care
about here (safety checks and snapshot_page()).
Can we please wait a bit so we have confirmation that it's not a
leftover from the huge-zero-folio thingy or something different?
As Mike reports, he found ways to reproduce something similar even with
39231e8d6ba7 reverted.
--
Cheers
David
