Re: [PATCH] rmap 15c

[Rik van Riel]

On Thu, 30 Jan 2003, Marc-Christian Petersen wrote:
> On Thursday 30 January 2003 14:32, Rik van Riel wrote:
>
> Hi Rik,
>
> > rmap 15c:
> >   - backport and audit akpm's reliable pte_chain alloc
> >     code from 2.5                                         (me)
> >   - reintroduce cache size tuning knobs in /proc          (me)
> >     | on very, very popular request
>
> GREAT to see this. Already merged for wolk4.0s-pre10 :)

Better merge this little patch, too.  Arjan spotted this
bug and now I'm not sure why rmap15c worked at all, let
alone why it survived a night of stress testing ... ;)

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
#	           ChangeSet	1.793   -> 1.794
#	           fs/exec.c	1.24    -> 1.25
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 03/01/31	[e-mail]	1.794
# uh oh, here we could end up freeing a used pte_chain
# (thanks arjan)
# --------------------------------------------
#
diff -Nru a/fs/exec.c b/fs/exec.c
--- a/fs/exec.c	Fri Jan 31 12:44:30 2003
+++ b/fs/exec.c	Fri Jan 31 12:44:30 2003
@@ -308,7 +308,7 @@
 	flush_dcache_page(page);
 	flush_page_to_ram(page);
 	set_pte(pte, pte_mkdirty(pte_mkwrite(mk_pte(page, PAGE_COPY))));
-	page_add_rmap(page, pte, pte_chain);
+	pte_chain = page_add_rmap(page, pte, pte_chain);
 	tsk->mm->rss++;
 	pte_unmap(pte);
 	spin_unlock(&tsk->mm->page_table_lock);

Rik
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