From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f175.google.com (mail-ig0-f175.google.com [209.85.213.175]) by kanga.kvack.org (Postfix) with ESMTP id 843E16B0253 for ; Tue, 8 Dec 2015 15:25:59 -0500 (EST) Received: by igcto18 with SMTP id to18so25200233igc.0 for ; Tue, 08 Dec 2015 12:25:59 -0800 (PST) Received: from smtprelay.hostedemail.com (smtprelay0249.hostedemail.com. [216.40.44.249]) by mx.google.com with ESMTPS id p19si9665791igr.55.2015.12.08.12.25.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 Dec 2015 12:25:58 -0800 (PST) Date: Tue, 8 Dec 2015 15:25:55 -0500 From: Steven Rostedt Subject: Re: [PATCH v3 2/7] mm/gup: add gup trace points Message-ID: <20151208152555.1c03ae54@gandalf.local.home> In-Reply-To: <1449603595-718-3-git-send-email-yang.shi@linaro.org> References: <1449603595-718-1-git-send-email-yang.shi@linaro.org> <1449603595-718-3-git-send-email-yang.shi@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Yang Shi Cc: akpm@linux-foundation.org, mingo@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linaro-kernel@lists.linaro.org On Tue, 8 Dec 2015 11:39:50 -0800 Yang Shi wrote: > For slow version, just add trace point for raw __get_user_pages since all > slow variants call it to do the real work finally. > > Signed-off-by: Yang Shi > --- > mm/gup.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/mm/gup.c b/mm/gup.c > index deafa2c..44f05c9 100644 > --- a/mm/gup.c > +++ b/mm/gup.c > @@ -18,6 +18,9 @@ > > #include "internal.h" > > +#define CREATE_TRACE_POINTS > +#include > + > static struct page *no_page_table(struct vm_area_struct *vma, > unsigned int flags) > { > @@ -462,6 +465,8 @@ long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm, > if (!nr_pages) > return 0; > > + trace_gup_get_user_pages(start, nr_pages); > + > VM_BUG_ON(!!pages != !!(gup_flags & FOLL_GET)); > > /* > @@ -599,6 +604,7 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm, > if (!(vm_flags & vma->vm_flags)) > return -EFAULT; > > + trace_gup_fixup_user_fault(address); > ret = handle_mm_fault(mm, vma, address, fault_flags); > if (ret & VM_FAULT_ERROR) { > if (ret & VM_FAULT_OOM) > @@ -1340,6 +1346,8 @@ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, > start, len))) > return 0; > > + trace_gup_get_user_pages_fast(start, (unsigned long) nr_pages); typecast shouldn't be needed. But I'm wondering, it would save space in the ring buffer if we used unsigend int instead of long. Will nr_pages ever be bigger than 4 billion? -- Steve > + > /* > * Disable interrupts. We use the nested form as we can already have > * interrupts disabled by get_futex_key. -- 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