From: Juan Perez-Sanchez <lithoxs@gmail.com>
To: linux-8086 <linux-8086@vger.kernel.org>
Cc: Jody Bruchon <jody@jodybruchon.com>
Subject: [PATCH 6 of 6]
Date: Sun, 17 Mar 2013 13:22:44 -0600 [thread overview]
Message-ID: <CAD6VGub-BLG2A2DY+zyWg8nn8=QBFB4hHvi1aEUc7NsX7yJqkQ@mail.gmail.com> (raw)
[-- Attachment #1: Type: text/plain, Size: 794 bytes --]
Hi,
Fixed a problem which produced a kernel message error when running
the command "fsck". Now that the implementation of read and write file
is cleaner, it was very easy to find and fix the problem in file
fs/block_dev.c.
General optimization in files arch/i86/drivers/block/doshd.c,
arch/i86/mm/init.c, arch/i86/mm/malloc.c, arch/i86/mm/user.c,
fs/buffer.c fs/minix/file.c, kernel/printk.c and kernel/sched.c,
removing unused variables and redundant statements, using pointers
instead of array indexing, using do{}while() whenever possible and
simplifying code.
3. As result of the modifications the code size was reduced in 112 bytes.
The Image builded without errors. The kernel was tested with QEMU and
dioscuri emulators. Also in a PPro pc booting from floppy.
Greetings,
Juan
[-- Attachment #2: elksZ.patch --]
[-- Type: application/octet-stream, Size: 7167 bytes --]
diff -Nurb elks.orig/arch/i86/drivers/block/doshd.c elks/arch/i86/drivers/block/doshd.c
--- elks.orig/arch/i86/drivers/block/doshd.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/arch/i86/drivers/block/doshd.c 2013-03-06 17:37:50.000000000 -0600
@@ -532,8 +532,8 @@
return 0;
#ifdef TEMP_PRINT_DRIVES_MAX
- for (i = 0; i < TEMP_PRINT_DRIVES_MAX; i++) {
- drivep = drive_info + i;
+ drivep = drive_info;
+ for (i = 0; i < TEMP_PRINT_DRIVES_MAX; i++, drivep++) {
if (drivep->heads != 0) {
char *unit = "kMGT";
__u32 size = ((__u32) drivep->sectors) * 5 /* 0.1 kB units */;
diff -Nurb elks.orig/arch/i86/mm/init.c elks/arch/i86/mm/init.c
--- elks.orig/arch/i86/mm/init.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/arch/i86/mm/init.c 2013-03-06 14:32:03.000000000 -0600
@@ -34,10 +34,11 @@
__u16 basemem = setupw(0x2a);
__u16 xms = setupw(2); /* Fetched by boot code */
- for (pi = 0; ((int)pi) < 16; pi++) {
+ pi = 0;
+ do {
proc_name[(int)pi] = setupb(0x30 + (int)pi);
cpuid[(int)pi] = setupb(0x50 + (int)pi);
- }
+ } while((int)(++pi) < 16);
proc_name[16] = cpuid[16] = '\0';
#ifdef CONFIG_ARCH_SIBO
@@ -52,7 +53,7 @@
arch_cpu > 5 ? 'A' : 'X', proc_name, basemem);
if (arch_cpu < 6)
xms = 0; /* XT bios hasn't got xms interrupt */
- if (xms)
+ else
printk(", %dK extended memory (XMS)", xms);
if (*cpuid)
printk(", CPUID `%s'", cpuid);
diff -Nurb elks.orig/arch/i86/mm/malloc.c elks/arch/i86/mm/malloc.c
--- elks.orig/arch/i86/mm/malloc.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/arch/i86/mm/malloc.c 2013-03-06 15:09:26.000000000 -0600
@@ -161,7 +161,7 @@
register struct malloc_hole *best = NULL;
while (m) {
- if (m->extent >= size && m->flags == HOLE_FREE)
+ if (m->flags == HOLE_FREE && m->extent >= size)
if (!best || best->extent > m->extent)
best = m;
m = m->next;
@@ -483,14 +483,14 @@
void mm_init(seg_t start, seg_t end)
{
- register struct malloc_hole *holep = &holes[0];
- register char *pct;
+ register struct malloc_hole *holep = &holes[MAX_SEGMENTS - 1];
/*
* Mark pages free.
*/
- for (pct = (char *) 1 ; ((int) pct) < MAX_SEGMENTS ; pct++)
- holes[(int)pct].flags = HOLE_SPARE;
+ do {
+ holep->flags = HOLE_SPARE;
+ } while(--holep > holes);
/*
* Single hole containing all user memory.
diff -Nurb elks.orig/arch/i86/mm/user.c elks/arch/i86/mm/user.c
--- elks.orig/arch/i86/mm/user.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/arch/i86/mm/user.c 2013-03-04 13:20:18.000000000 -0600
@@ -228,7 +228,8 @@
int fs_memcmp(void *s, void *d, size_t len)
{
- unsigned char *p1 = s, *p2 = d;
+ register unsigned char *p1 = s;
+ register unsigned char *p2 = d;
int c = 0;
while (len-- && !c)
diff -Nurb elks.orig/fs/block_dev.c elks/fs/block_dev.c
--- elks.orig/fs/block_dev.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/fs/block_dev.c 2013-03-04 19:11:19.000000000 -0600
@@ -23,13 +23,11 @@
char *buf, size_t count, int wr)
{
register struct buffer_head *bh;
- block_t block;
kdev_t dev;
unsigned int offset;
size_t chars;
- int written;
+ int written = 0;
- written = 0;
dev = inode->i_rdev;
while (count > 0) {
@@ -37,7 +35,6 @@
/*
* Offset to block/offset
*/
- block = (block_t) (filp->f_pos >> BLOCK_SIZE_BITS);
offset = ((unsigned int)filp->f_pos) & (BLOCK_SIZE - 1);
/*
@@ -50,15 +47,13 @@
* Read the block in - use getblk on a write
* of a whole block to avoid a read of the data.
*/
- if(wr == BLOCK_WRITE && chars == BLOCK_SIZE) {
- bh = getblk(dev, block);
- map_buffer(bh);
- } else {
- bh = bread(dev, block);
- if (!bh)
+ bh = getblk(dev, (block_t)(filp->f_pos >> BLOCK_SIZE_BITS));
+ if((wr == BLOCK_READ) || (chars != BLOCK_SIZE)) {
+ if (!readbuf(bh))
return written ? written : -EIO;
}
+ map_buffer(bh);
if (wr == BLOCK_WRITE) {
/*
* Alter buffer, mark dirty
diff -Nurb elks.orig/fs/buffer.c elks/fs/buffer.c
--- elks.orig/fs/buffer.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/fs/buffer.c 2013-03-04 13:20:18.000000000 -0600
@@ -204,15 +204,14 @@
{
register struct buffer_head *bh;
- for (;;) {
- if (!(bh = find_buffer(dev, block)))
- return NULL;
+ while((bh = find_buffer(dev, block))) {
bh->b_count++;
wait_on_buffer(bh);
if (bh->b_dev == dev && bh->b_blocknr == block)
- return bh;
+ break;
bh->b_count--;
}
+ return bh;
}
/*
@@ -235,11 +234,10 @@
* now so as to ensure that there are still clean buffers available
* for user processes to use (and dirty) */
- for (;;) {
+ do {
bh = get_hash_table(dev, block);
if (bh != NULL) {
- if (buffer_clean(bh))
- if (buffer_uptodate(bh))
+ if (buffer_clean(bh) && buffer_uptodate(bh))
put_last_lru(bh);
return bh;
}
@@ -248,9 +246,7 @@
* So I will remove it for now
*/
- if (!find_buffer(dev, block))
- break;
- }
+ } while(find_buffer(dev, block));
/*
* Create a buffer for this job.
diff -Nurb elks.orig/fs/minix/file.c elks/fs/minix/file.c
--- elks.orig/fs/minix/file.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/fs/minix/file.c 2013-03-04 19:02:17.000000000 -0600
@@ -195,7 +195,7 @@
written = -ENOSPC;
break;
}
- if (chars != BLOCK_SIZE && !buffer_uptodate(bh)) {
+ if (chars != BLOCK_SIZE) {
if (!readbuf(bh)) {
if (!written)
written = -EIO;
diff -Nurb elks.orig/kernel/printk.c elks/kernel/printk.c
--- elks.orig/kernel/printk.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/kernel/printk.c 2013-03-05 15:59:41.000000000 -0600
@@ -74,7 +74,8 @@
static void numout(unsigned long v, int width, int base, int useSign,
int Upper, int Zero)
{
- char *bp, *bp2;
+ register char *bp;
+ char *bp2;
char buf[12];
if (width > sizeof(buf)) /* Error-check width specified */
@@ -206,7 +207,8 @@
void panic(char *error, ...)
{
va_list p;
- int *bp = (int *) &error - 2, i = 0, j;
+ register int *bp = (int *) &error - 2;
+ int i = 0, j;
kputs("\npanic: ");
va_start(p, error);
diff -Nurb elks.orig/kernel/sched.c elks/kernel/sched.c
--- elks.orig/kernel/sched.c 2013-03-04 13:20:07.000000000 -0600
+++ elks/kernel/sched.c 2013-03-04 13:20:18.000000000 -0600
@@ -48,8 +48,7 @@
return;
}
nr_running--;
- p->next_run->prev_run = p->prev_run;
- p->prev_run->next_run = p->next_run;
+ (p->next_run->prev_run = p->prev_run)->next_run = p->next_run;
p->next_run = p->prev_run = NULL;
#ifdef CONFIG_SWAP
p->last_running = jiffies;
@@ -207,14 +206,12 @@
do {
prev = next;
- if (!(next = next->tl_next))
- goto link_tmr;
- } while(next->tl_expires < timer->tl_expires);
+ } while((next = next->tl_next) && (next->tl_expires < timer->tl_expires));
- (timer->tl_next = next)->tl_prev = timer;
-
- link_tmr:
(timer->tl_prev = prev)->tl_next = timer;
+ if((timer->tl_next = next))
+ next->tl_prev = timer;
+
restore_flags(flags);
}
reply other threads:[~2013-03-17 19:22 UTC|newest]
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