From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx140.postini.com [74.125.245.140]) by kanga.kvack.org (Postfix) with SMTP id 47F096B004D for ; Thu, 2 Aug 2012 10:06:44 -0400 (EDT) Date: Thu, 2 Aug 2012 09:06:41 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH] slub: use free_page instead of put_page for freeing kmalloc allocation In-Reply-To: <1343913065-14631-1-git-send-email-glommer@parallels.com> Message-ID: References: <1343913065-14631-1-git-send-email-glommer@parallels.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Glauber Costa Cc: linux-kernel@vger.kernel.org, Andrew Morton , linux-mm@kvack.org, David Rientjes , Pekka Enberg On Thu, 2 Aug 2012, Glauber Costa wrote: > diff --git a/mm/slub.c b/mm/slub.c > index e517d43..9ca4e20 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -3453,7 +3453,7 @@ void kfree(const void *x) > if (unlikely(!PageSlab(page))) { > BUG_ON(!PageCompound(page)); > kmemleak_free(x); > - put_page(page); > + __free_pages(page, compound_order(page)); Hmmm... put_page would have called put_compound_page(). which would have called the dtor function. dtor is set to __free_pages() ok which does mlock checks and verifies that the page is in a proper condition for freeing. Then it calls free_one_page(). __free_pages() decrements the refcount and then calls __free_pages_ok(). So we loose the checking and the dtor stuff with this patch. Guess that is ok? Acked-by: Christoph Lameter -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org