Messages in this thread | | | Subject | Re: [PATCH 1/2] kmemleak: Inform kmemleak about kernel stack allocation | From | Catalin Marinas <> | Date | Sat, 29 Aug 2009 16:08:42 +0100 |
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On Sat, 2009-08-29 at 15:28 +0100, Catalin Marinas wrote: > On Sat, 2009-08-29 at 15:29 +0200, Ingo Molnar wrote: > > * Catalin Marinas <catalin.marinas@arm.com> wrote: > > > > > Traversing all the tasks in the system for scanning the kernel > > > stacks requires locking which increases the kernel latency > > > considerably. This patch informs kmemleak about newly allocated or > > > freed stacks so that they are treated as any other allocated > > > object. Subsequent patch will remove the explicit stack scanning > > > from mm/kmemleak.c. > > > > > > Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> > > > Cc: Ingo Molnar <mingo@redhat.com> > > > --- > > > arch/x86/include/asm/thread_info.h | 7 ++++++- > > > arch/x86/kernel/process.c | 2 ++ > > > kernel/fork.c | 7 ++++++- > > > 3 files changed, 14 insertions(+), 2 deletions(-) > > > > > > diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h > > > index fad7d40..f26432a 100644 > > > --- a/arch/x86/include/asm/thread_info.h > > > +++ b/arch/x86/include/asm/thread_info.h > > > @@ -162,7 +162,12 @@ struct thread_info { > > > #define __HAVE_ARCH_THREAD_INFO_ALLOCATOR > > > > > > #define alloc_thread_info(tsk) \ > > > - ((struct thread_info *)__get_free_pages(THREAD_FLAGS, THREAD_ORDER)) > > > +({ \ > > > + struct thread_info *ti = (struct thread_info *) \ > > > + __get_free_pages(THREAD_FLAGS, THREAD_ORDER); \ > > > + kmemleak_alloc(ti, THREAD_SIZE, 1, THREAD_FLAGS); \ > > > + ti; \ > > > +}) > > > > Sidenote:this used to be a trivial wrapper to gfp so it was > > borderline OK as a CPP macro - now it's a non-trivial CPP wrapper > > macro which is not OK. Mind converting it to an inline function? > > I tried this first but got compilation errors in files that didn't even > call this function. To make it workable, thread_info.h would need to > include additional headers. If that's acceptable, I can post an updated > patch.
Actually I think it's only the kmemleak.h header but it would get included via thread_info.h in many other files. An alternative is to make kmemleak_alloc() etc. return the pointer passed as argument and keep the macro something like:
kmemleak_alloc(__get_free_pages(...), ...)
though it is still a bit long.
-- Catalin
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