linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Johannes Weiner <hannes@cmpxchg.org>
To: "Andrew Morton" <akpm@linux-foundation.org>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: [patch 1/4] mm: page_alloc: remove order assumption from __free_pages_bootmem()
Date: Tue, 13 Dec 2011 14:58:28 +0100	[thread overview]
Message-ID: <1323784711-1937-2-git-send-email-hannes@cmpxchg.org> (raw)
In-Reply-To: <1323784711-1937-1-git-send-email-hannes@cmpxchg.org>

Even though bootmem passes an order with the page to be freed,
__free_pages_bootmem() assumes that 1 << order is always BITS_PER_LONG
if non-zero.  While this happens to be true, it's not really robust.
Remove that assumption and use 1 << order instead.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
---
 mm/page_alloc.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 2b8ba3a..4d5e91c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -703,13 +703,14 @@ void __meminit __free_pages_bootmem(struct page *page, unsigned int order)
 		set_page_refcounted(page);
 		__free_page(page);
 	} else {
-		int loop;
+		unsigned int nr_pages = 1 << order;
+		unsigned int loop;
 
 		prefetchw(page);
-		for (loop = 0; loop < BITS_PER_LONG; loop++) {
+		for (loop = 0; loop < nr_pages; loop++) {
 			struct page *p = &page[loop];
 
-			if (loop + 1 < BITS_PER_LONG)
+			if (loop + 1 < nr_pages)
 				prefetchw(p + 1);
 			__ClearPageReserved(p);
 			set_page_count(p, 0);
-- 
1.7.7.3

--
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/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>

  reply	other threads:[~2011-12-13 13:58 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-13 13:58 [patch 0/4] mm: bootmem / page allocator bootstrap fixlets Johannes Weiner
2011-12-13 13:58 ` Johannes Weiner [this message]
2011-12-13 22:05   ` [patch 1/4] mm: page_alloc: remove order assumption from __free_pages_bootmem() Andrew Morton
2011-12-13 13:58 ` [patch 2/4] mm: page_alloc: generalize order handling in __free_pages_bootmem() Johannes Weiner
2011-12-13 13:58 ` [patch 3/4] mm: bootmem: drop superfluous range check when freeing pages in bulk Johannes Weiner
2011-12-13 15:28   ` Uwe Kleine-König
2011-12-13 15:44     ` Johannes Weiner
2011-12-13 13:58 ` [patch 4/4] mm: bootmem: try harder to free " Johannes Weiner
2011-12-14 20:20   ` Uwe Kleine-König
2011-12-14 20:42     ` Johannes Weiner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1323784711-1937-2-git-send-email-hannes@cmpxchg.org \
    --to=hannes@cmpxchg.org \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=u.kleine-koenig@pengutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).