On Sat, 26 Jan 2008, Andrew Morton wrote:

On Thu, 24 Jan 2008 10:50:29 -0600 David Teigland <[EMAIL PROTECTED]> wrote:
From: Fabio M. Di Nitto <[EMAIL PROTECTED]>

gcc does not guarantee that a static buffer is 64bit aligned. This change
allows sparc64 to work.


This buffer is not static: changelog needs fixing: s/static/auto/

---
 fs/dlm/midcomms.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c
index f8c69dd..da653b5 100644
--- a/fs/dlm/midcomms.c
+++ b/fs/dlm/midcomms.c
@@ -58,7 +58,7 @@ static void copy_from_cb(void *dst, const void *base, 
unsigned offset,
 int dlm_process_incoming_buffer(int nodeid, const void *base,
                                unsigned offset, unsigned len, unsigned limit)
 {
-       unsigned char __tmp[DLM_INBUF_LEN];
+       unsigned char __tmp[DLM_INBUF_LEN] __attribute__((aligned(64)));
        struct dlm_header *msg = (struct dlm_header *) __tmp;
        int ret = 0;
        int err = 0;

Why does DLM require that this thing be 64-bit aligned?

It all looks rather ugly.  Can't this stuff be implemeted within the C type
system somehow?


how about this one:

From adfe3b0654583d34b0840d20a69e4306d5b98caf Mon Sep 17 00:00:00 2001
Message-Id: <[EMAIL PROTECTED]>
From: Fabio M. Di Nitto <[EMAIL PROTECTED]>
Date: Tue, 29 Jan 2008 06:35:20 +0100
Subject: [PATCH 1/1] dlm: align midcomms message buffer

gcc does not guarantee that an auto buffer is 64bit aligned.
This change allows sparc64 to work.

Signed-off-by: Fabio M. Di Nitto <[EMAIL PROTECTED]>
---
:100644 100644 f8c69dd... 53b7af2... M  fs/dlm/midcomms.c
 fs/dlm/midcomms.c |   13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/dlm/midcomms.c b/fs/dlm/midcomms.c
index f8c69dd..53b7af2 100644
--- a/fs/dlm/midcomms.c
+++ b/fs/dlm/midcomms.c
@@ -58,8 +58,11 @@ static void copy_from_cb(void *dst, const void *base, 
unsigned offset,
 int dlm_process_incoming_buffer(int nodeid, const void *base,
                                unsigned offset, unsigned len, unsigned limit)
 {
-       unsigned char __tmp[DLM_INBUF_LEN];
-       struct dlm_header *msg = (struct dlm_header *) __tmp;
+       union {
+               unsigned char __buf[DLM_INBUF_LEN];
+               struct dlm_header dlm;
+       } __tmp;
+       struct dlm_header *msg = &__tmp.dlm;
        int ret = 0;
        int err = 0;
        uint16_t msglen;
@@ -100,8 +103,8 @@ int dlm_process_incoming_buffer(int nodeid, const void 
*base,
                   in the buffer on the stack (which should work for most
                   ordinary messages). */

-               if (msglen > sizeof(__tmp) &&
-                   msg == (struct dlm_header *) __tmp) {
+               if (msglen > DLM_INBUF_LEN &&
+                   msg == &__tmp.dlm) {
                        msg = kmalloc(dlm_config.ci_buffer_size, GFP_KERNEL);
                        if (msg == NULL)
                                return ret;
@@ -119,7 +122,7 @@ int dlm_process_incoming_buffer(int nodeid, const void 
*base,
                dlm_receive_buffer(msg, nodeid);
        }

-       if (msg != (struct dlm_header *) __tmp)
+       if (msg != &__tmp.dlm)
                kfree(msg);

        return err ? err : ret;
--
1.5.3.8


--
I'm going to make him an offer he can't refuse.
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