public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Adrian Bunk <bunk@stusta.de>
To: spyro@f2s.com
Cc: linux-kernel@vger.kernel.org
Subject: [2.6 patch] fix arm26 THREAD_SIZE
Date: Fri, 6 Jan 2006 17:16:08 +0100	[thread overview]
Message-ID: <20060106161608.GG12131@stusta.de> (raw)

arm26 currently has a 256 kB THREAD_SIZE (sic).

Looking at the comment in the code, this seems to be based on a 
misunderstanding.

The comment says:
this needs attention (see kernel/fork.c which gets a nice div by zero if 
this is lower than 8*32768

kernel/fork.c does:
  max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE)

Therefore, a division by 0 is impossible for all reasonable cases with
THREAD_SIZE >= PAGE_SIZE.

Since the minimum PAGE_SIZE Linux uses on the arm26 architecture is 16k, 
PAGE_SIZE should be sufficient for THREAD_SIZE.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

--- linux-2.6.15-mm1-full/include/asm-arm26/thread_info.h.old	2006-01-06 16:45:40.000000000 +0100
+++ linux-2.6.15-mm1-full/include/asm-arm26/thread_info.h	2006-01-06 16:46:07.000000000 +0100
@@ -80,8 +80,7 @@
 	return (struct thread_info *)(sp & ~0x1fff);
 }
 
-/* FIXME - PAGE_SIZE < 32K */
-#define THREAD_SIZE		(8*32768) // FIXME - this needs attention (see kernel/fork.c which gets a nice div by zero if this is lower than 8*32768
+#define THREAD_SIZE	PAGE_SIZE
 #define task_pt_regs(task) ((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE - 8) - 1)
 
 extern struct thread_info *alloc_thread_info(struct task_struct *task);


             reply	other threads:[~2006-01-06 16:16 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-01-06 16:16 Adrian Bunk [this message]
2006-01-07  0:37 ` [2.6 patch] fix arm26 THREAD_SIZE Ian Molton
  -- strict thread matches above, loose matches on Subject: below --
2006-01-09 22:22 Adrian Bunk

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=20060106161608.GG12131@stusta.de \
    --to=bunk@stusta.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=spyro@f2s.com \
    /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