On Tue, Jan 26, 2016 at 03:29:38PM -0800, David Rientjes wrote: > On Tue, 26 Jan 2016, Heiko Carstens wrote: > > > On Tue, Jan 26, 2016 at 10:18:25AM +0100, Christian Borntraeger wrote: > > > We can use debug_pagealloc_enabled() to check if we can map > > > the identity mapping with 1MB/2GB pages as well as to print > > > the current setting in dump_stack. > > > > > > Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx> > > > --- > > > arch/s390/kernel/dumpstack.c | 4 +++- > > > arch/s390/mm/vmem.c | 10 ++++------ > > > 2 files changed, 7 insertions(+), 7 deletions(-) > > > > > > diff --git a/arch/s390/kernel/dumpstack.c b/arch/s390/kernel/dumpstack.c > > > index dc8e204..a1c0530 100644 > > > --- a/arch/s390/kernel/dumpstack.c > > > +++ b/arch/s390/kernel/dumpstack.c > > > @@ -11,6 +11,7 @@ > > > #include <linux/export.h> > > > #include <linux/kdebug.h> > > > #include <linux/ptrace.h> > > > +#include <linux/mm.h> > > > #include <linux/module.h> > > > #include <linux/sched.h> > > > #include <asm/processor.h> > > > @@ -186,7 +187,8 @@ void die(struct pt_regs *regs, const char *str) > > > printk("SMP "); > > > #endif > > > #ifdef CONFIG_DEBUG_PAGEALLOC > > > - printk("DEBUG_PAGEALLOC"); > > > + printk("DEBUG_PAGEALLOC(%s)", > > > + debug_pagealloc_enabled() ? "enabled" : "disabled"); > > > #endif > > > > I'd prefer if you change this to > > > > if (debug_pagealloc_enabled()) > > printk("DEBUG_PAGEALLOC"); > > > > That way we can get rid of yet another ifdef. Having > > "DEBUG_PAGEALLOC(disabled)" doesn't seem to be very helpful. > > > > I'd agree if CONFIG_DEBUG_PAGEALLOC only did anything when > debug_pagealloc_enabled() is true, but that doesn't seem to be the case. > When CONFIG_DEBUG_SLAB is enabled, for instance, CONFIG_DEBUG_PAGEALLOC > also enables stackinfo storing and poisoning and it's not guarded by > debug_pagealloc_enabled(). > > It seems like CONFIG_DEBUG_PAGEALLOC enables debugging functionality > outside the scope of the debug_pagealloc=on kernel parameter, so > DEBUG_PAGEALLOC(disabled) actually does mean something. Hello, David. I tried to fix CONFIG_DEBUG_SLAB case on 04/16 of following patchset. http://thread.gmane.org/gmane.linux.kernel.mm/144527 I found that there are more sites to fix but not so many. We can do it. Thanks. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>