• Stephen Boyd's avatar
    slub: restore slub_debug=- behavior · 02ac47d0
    Stephen Boyd authored
    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@chromium.org
    Link: https://lkml.kernel.org/r/20210601182202.3011020-2-swboyd@chromium.org
    Fixes: ca0cab65 ("mm, slub: introduce static key for slub_debug()")
    Signed-off-by: default avatarStephen Boyd <swboyd@chromium.org>
    Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
    Reviewed-by: default avatarMuchun Song <songmuchun@bytedance.com>
    Cc: Christoph Lameter <cl@linux.com>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Joe Perches <joe@perches.com>
    Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    Cc: Pekka Enberg <penberg@kernel.org>
    Cc: Petr Mladek <pmladek@suse.com>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    02ac47d0
slub.c 142 KB