From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Mathieu Desnoyers <compudj@krystal.dyndns.org>,
Steven Rostedt <srostedt@redhat.com>
Subject: [PATCH 4/6] ring_buffer: reset buffer page when freeing
Date: Mon, 29 Sep 2008 23:02:40 -0400 [thread overview]
Message-ID: <20080930030652.497934332@goodmis.org> (raw)
In-Reply-To: 20080930030236.230994826@goodmis.org
[-- Attachment #1: ring-buffer-page-freeing.patch --]
[-- Type: text/plain, Size: 2008 bytes --]
Mathieu Desnoyers pointed out that the freeing of the page frame needs
to be reset otherwise we might trigger BUG_ON in the page free code.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
kernel/trace/ring_buffer.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
Index: linux-tip.git/kernel/trace/ring_buffer.c
===================================================================
--- linux-tip.git.orig/kernel/trace/ring_buffer.c 2008-09-29 19:59:24.000000000 -0400
+++ linux-tip.git/kernel/trace/ring_buffer.c 2008-09-29 20:07:32.000000000 -0400
@@ -128,6 +128,17 @@ struct buffer_page {
};
/*
+ * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing
+ * this issue out.
+ */
+static inline void free_buffer_page(struct buffer_page *bpage)
+{
+ reset_page_mapcount(&bpage->page);
+ bpage->page.mapping = NULL;
+ __free_page(&bpage->page);
+}
+
+/*
* We need to fit the time_stamp delta into 27 bits.
*/
static inline int test_time_stamp(u64 delta)
@@ -240,7 +251,7 @@ static int rb_allocate_pages(struct ring
free_pages:
list_for_each_entry_safe(page, tmp, &pages, list) {
list_del_init(&page->list);
- __free_page(&page->page);
+ free_buffer_page(page);
}
return -ENOMEM;
}
@@ -284,7 +295,7 @@ static void rb_free_cpu_buffer(struct ri
list_for_each_entry_safe(page, tmp, head, list) {
list_del_init(&page->list);
- __free_page(&page->page);
+ free_buffer_page(page);
}
kfree(cpu_buffer);
}
@@ -393,7 +404,7 @@ rb_remove_pages(struct ring_buffer_per_c
p = cpu_buffer->pages.next;
page = list_entry(p, struct buffer_page, list);
list_del_init(&page->list);
- __free_page(&page->page);
+ free_buffer_page(page);
}
BUG_ON(list_empty(&cpu_buffer->pages));
@@ -520,7 +531,7 @@ int ring_buffer_resize(struct ring_buffe
free_pages:
list_for_each_entry_safe(page, tmp, &pages, list) {
list_del_init(&page->list);
- __free_page(&page->page);
+ free_buffer_page(page);
}
return -ENOMEM;
}
--
next prev parent reply other threads:[~2008-09-30 3:07 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-30 3:02 [PATCH 0/6] ftrace: port to the new ring_buffer Steven Rostedt
2008-09-30 3:02 ` [PATCH 1/6] ftrace: give time for wakeup test to run Steven Rostedt
2008-09-30 3:02 ` [PATCH 2/6] Unified trace buffer Steven Rostedt
2008-09-30 9:45 ` Ingo Molnar
2008-09-30 11:53 ` Ingo Molnar
2008-09-30 12:06 ` Steven Rostedt
2008-09-30 3:02 ` [PATCH 3/6] ring_buffer: add paranoid check for buffer page Steven Rostedt
2008-09-30 3:02 ` Steven Rostedt [this message]
2008-09-30 3:02 ` [PATCH 5/6] ftrace: make work with new ring buffer Steven Rostedt
2008-09-30 3:02 ` [PATCH 6/6] ftrace: take advantage of variable length entries Steven Rostedt
2008-09-30 17:33 ` Pekka Paalanen
2008-09-30 17:45 ` Steven Rostedt
2008-10-01 4:42 ` Steven Rostedt
2008-10-01 7:54 ` Ingo Molnar
2008-10-01 14:52 ` Steven Rostedt
2008-10-01 14:52 ` [PATCH] ftrace: type cast verifier Steven Rostedt
2008-10-01 17:42 ` Ingo Molnar
2008-10-01 17:47 ` Ingo Molnar
2008-09-30 7:45 ` [PATCH 0/6] ftrace: port to the new ring_buffer Ingo Molnar
2008-09-30 8:23 ` Ingo Molnar
2008-09-30 8:30 ` Ingo Molnar
2008-09-30 9:13 ` Ingo Molnar
2008-09-30 12:04 ` Steven Rostedt
2008-09-30 12:04 ` Steven Rostedt
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