From: npiggin@suse.de
To: akpm@linux-foundation.org, torvalds@linux-foundation.org
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
benh@kernel.crashing.org, paulus@samba.org
Subject: [patch 1/7] mm: readahead scan lockless
Date: Thu, 05 Jun 2008 19:43:01 +1000 [thread overview]
Message-ID: <20080605094825.530462000@nick.local0.net> (raw)
In-Reply-To: <20080605094300.295184000@nick.local0.net>
[-- Attachment #1: mm-readahead-scan-lockless.patch --]
[-- Type: text/plain, Size: 997 bytes --]
radix_tree_next_hole is implemented as a series of radix_tree_lookup()s. So
it can be called locklessly, under rcu_read_lock().
Signed-off-by: Nick Piggin <npiggin@suse.de>
---
Index: linux-2.6/mm/readahead.c
===================================================================
--- linux-2.6.orig/mm/readahead.c
+++ linux-2.6/mm/readahead.c
@@ -382,9 +382,9 @@ ondemand_readahead(struct address_space
if (hit_readahead_marker) {
pgoff_t start;
- read_lock_irq(&mapping->tree_lock);
- start = radix_tree_next_hole(&mapping->page_tree, offset, max+1);
- read_unlock_irq(&mapping->tree_lock);
+ rcu_read_lock();
+ start = radix_tree_next_hole(&mapping->page_tree, offset,max+1);
+ rcu_read_unlock();
if (!start || start - offset > max)
return 0;
--
--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2008-06-05 9:43 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-05 9:43 [patch 0/7] speculative page references, lockless pagecache, lockless gup npiggin
2008-06-05 9:43 ` npiggin [this message]
2008-06-05 9:43 ` [patch 2/7] radix-tree: add gang_lookup_slot, gang_lookup_slot_tag npiggin
2008-06-05 9:43 ` [patch 3/7] mm: speculative page references npiggin
2008-06-06 14:20 ` Peter Zijlstra
2008-06-06 16:26 ` Nick Piggin
2008-06-06 16:27 ` Nick Piggin
2008-06-09 4:48 ` Tim Pepper
2008-06-10 19:08 ` Christoph Lameter
2008-06-11 3:19 ` Nick Piggin
2008-06-05 9:43 ` [patch 4/7] mm: lockless pagecache npiggin
2008-06-05 9:43 ` [patch 5/7] mm: spinlock tree_lock npiggin
2008-06-05 9:43 ` [patch 6/7] powerpc: implement pte_special npiggin
2008-06-06 4:04 ` Benjamin Herrenschmidt
2008-06-05 9:43 ` [patch 7/7] powerpc: lockless get_user_pages_fast npiggin
2008-06-09 8:32 ` Andrew Morton
2008-06-10 3:15 ` Nick Piggin
2008-06-10 19:00 ` Christoph Lameter
2008-06-11 3:18 ` Nick Piggin
2008-06-11 4:40 ` Christoph Lameter
2008-06-11 4:41 ` Christoph Lameter
2008-06-11 4:49 ` Nick Piggin
2008-06-11 6:06 ` Andrew Morton
2008-06-11 6:24 ` Nick Piggin
2008-06-11 6:50 ` Andrew Morton
2008-06-11 23:20 ` Christoph Lameter
2008-06-11 4:47 ` Nick Piggin
2008-06-05 11:53 ` [patch 0/7] speculative page references, lockless pagecache, lockless gup Nick Piggin
2008-06-05 17:33 ` Linus Torvalds
2008-06-06 0:08 ` Nick Piggin
2008-06-06 21:32 ` Peter Zijlstra
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=20080605094825.530462000@nick.local0.net \
--to=npiggin@suse.de \
--cc=akpm@linux-foundation.org \
--cc=benh@kernel.crashing.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=paulus@samba.org \
--cc=torvalds@linux-foundation.org \
/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