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: 772 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;
--
WARNING: multiple messages have this Message-ID (diff)
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 10:00 UTC|newest]
Thread overview: 62+ 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
2008-06-05 9:43 ` npiggin [this message]
2008-06-05 9:43 ` [patch 1/7] mm: readahead scan lockless npiggin
2008-06-05 9:43 ` [patch 2/7] radix-tree: add gang_lookup_slot, gang_lookup_slot_tag npiggin
2008-06-05 9:43 ` npiggin
2008-06-05 9:43 ` [patch 3/7] mm: speculative page references npiggin
2008-06-05 9:43 ` npiggin
2008-06-06 14:20 ` Peter Zijlstra
2008-06-06 14:20 ` Peter Zijlstra
2008-06-06 16:26 ` Nick Piggin
2008-06-06 16:26 ` Nick Piggin
2008-06-06 16:27 ` Nick Piggin
2008-06-06 16:27 ` Nick Piggin
2008-06-09 4:48 ` Tim Pepper
2008-06-09 4:48 ` Tim Pepper
2008-06-10 19:08 ` Christoph Lameter
2008-06-10 19:08 ` Christoph Lameter
2008-06-11 3:19 ` Nick Piggin
2008-06-11 3:19 ` Nick Piggin
2008-06-05 9:43 ` [patch 4/7] mm: lockless pagecache npiggin
2008-06-05 9:43 ` npiggin
2008-06-05 9:43 ` [patch 5/7] mm: spinlock tree_lock npiggin
2008-06-05 9:43 ` npiggin
2008-06-05 9:43 ` [patch 6/7] powerpc: implement pte_special npiggin
2008-06-05 9:43 ` npiggin
2008-06-06 4:04 ` Benjamin Herrenschmidt
2008-06-06 4:04 ` Benjamin Herrenschmidt
2008-06-05 9:43 ` [patch 7/7] powerpc: lockless get_user_pages_fast npiggin
2008-06-05 9:43 ` npiggin
2008-06-09 8:32 ` Andrew Morton
2008-06-09 8:32 ` Andrew Morton
2008-06-10 3:15 ` Nick Piggin
2008-06-10 3:15 ` Nick Piggin
2008-06-10 19:00 ` Christoph Lameter
2008-06-10 19:00 ` Christoph Lameter
2008-06-11 3:18 ` Nick Piggin
2008-06-11 3:18 ` Nick Piggin
2008-06-11 4:40 ` Christoph Lameter
2008-06-11 4:40 ` Christoph Lameter
2008-06-11 4:41 ` Christoph Lameter
2008-06-11 4:41 ` Christoph Lameter
2008-06-11 4:49 ` Nick Piggin
2008-06-11 4:49 ` Nick Piggin
2008-06-11 6:06 ` Andrew Morton
2008-06-11 6:06 ` Andrew Morton
2008-06-11 6:24 ` Nick Piggin
2008-06-11 6:24 ` Nick Piggin
2008-06-11 6:50 ` Andrew Morton
2008-06-11 6:50 ` Andrew Morton
2008-06-11 23:20 ` Christoph Lameter
2008-06-11 23:20 ` Christoph Lameter
2008-06-11 4:47 ` Nick Piggin
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 11:53 ` Nick Piggin
2008-06-05 17:33 ` Linus Torvalds
2008-06-05 17:33 ` Linus Torvalds
2008-06-06 0:08 ` Nick Piggin
2008-06-06 0:08 ` Nick Piggin
2008-06-06 21:32 ` Peter Zijlstra
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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.