The patch titled Subject: slub: restore slub_debug=- behavior has been added to the -mm tree. Its filename is slub-restore-slub_debug=-behavior.patch This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/slub-restore-slub_debug%3D-behavior.patch and later at https://ozlabs.org/~akpm/mmotm/broken-out/slub-restore-slub_debug%3D-behavior.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Stephen Boyd <swboyd@xxxxxxxxxxxx> Subject: slub: restore slub_debug=- behavior Petch series "slub: Print non-hashed pointers in slub debugging", v3. I was doing some debugging recently and noticed that my pointers were being hashed while slub_debug was on the kernel commandline. Let's force on the no hash pointer option when slub_debug is on the kernel commandline so that the prints are more meaningful. The first two patches are something else I noticed while looking at the code. The message argument is never used so the debugging messages are not as clear as they could be and the slub_debug=- behavior seems to be busted. Then there's a printf fixup from Joe and the final patch is the one that force disables pointer hashing. This patch (of 4): Passing slub_debug=- on the kernel commandline is supposed to disable slub debugging. This is especially useful with CONFIG_SLUB_DEBUG_ON where the default is to have slub debugging enabled in the build. Due to some code reorganization this behavior was dropped, but the code to make it work mostly stuck around. Restore the previous behavior by disabling the static key when we parse the commandline and see that we're trying to disable slub debugging. Link: https://lkml.kernel.org/r/20210601182202.3011020-1-swboyd@xxxxxxxxxxxx Link: https://lkml.kernel.org/r/20210601182202.3011020-2-swboyd@xxxxxxxxxxxx Fixes: ca0cab65ea2b ("mm, slub: introduce static key for slub_debug()") Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Petr Mladek <pmladek@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slub.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/slub.c~slub-restore-slub_debug=-behavior +++ a/mm/slub.c @@ -1428,6 +1428,8 @@ static int __init setup_slub_debug(char out: if (slub_debug != 0 || slub_debug_string) static_branch_enable(&slub_debug_enabled); + else + static_branch_disable(&slub_debug_enabled); if ((static_branch_unlikely(&init_on_alloc) || static_branch_unlikely(&init_on_free)) && (slub_debug & SLAB_POISON)) _ Patches currently in -mm which might be from swboyd@xxxxxxxxxxxx are slub-restore-slub_debug=-behavior.patch slub-actually-use-message-in-restore_bytes.patch slub-force-on-no_hash_pointers-when-slub_debug-is-enabled.patch buildid-only-consider-gnu-notes-for-build-id-parsing.patch buildid-add-api-to-parse-build-id-out-of-buffer.patch buildid-stash-away-kernels-build-id-on-init.patch buildid-stash-away-kernels-build-id-on-init-fix.patch dump_stack-add-vmlinux-build-id-to-stack-traces.patch module-add-printk-formats-to-add-module-build-id-to-stacktraces.patch arm64-stacktrace-use-%psb-for-backtrace-printing.patch x86-dumpstack-use-%psb-%pbb-for-backtrace-printing.patch scripts-decode_stacktracesh-support-debuginfod.patch scripts-decode_stacktracesh-silence-stderr-messages-from-addr2line-nm.patch scripts-decode_stacktracesh-indicate-auto-can-be-used-for-base-path.patch buildid-mark-some-arguments-const.patch buildid-fix-kernel-doc-notation.patch kdump-use-vmlinux_build_id-to-simplify.patch