Re: [PATCH 2.6.19-rc6] sparc: replace kmalloc+memset with kzalloc

From: Yan Burman
Date: Fri Nov 24 2006 - 14:07:00 EST


Stefan Richter wrote:
Yan Burman wrote:
...
--- linux-2.6.19-rc5_orig/arch/sparc/kernel/sun4d_irq.c 2006-11-09 12:16:21.000000000 +0200
+++ linux-2.6.19-rc5_kzalloc/arch/sparc/kernel/sun4d_irq.c 2006-11-11 22:44:04.000000000 +0200
@@ -545,8 +545,7 @@ void __init sun4d_init_sbi_irq(void)
nsbi = 0;
for_each_sbus(sbus)
nsbi++;
- sbus_actions = (struct sbus_action *)kmalloc (nsbi * 8 * 4 * sizeof(struct sbus_action), GFP_ATOMIC);
- memset (sbus_actions, 0, (nsbi * 8 * 4 * sizeof(struct sbus_action)));
+ sbus_actions = kzalloc (nsbi * 8 * 4 * sizeof(struct sbus_action), GFP_ATOMIC);
for_each_sbus(sbus) {
#ifdef CONFIG_SMP
extern unsigned char boot_cpu_id;

I'm not sure about this ^ hunk, but...

diff -rubp linux-2.6.19-rc5_orig/arch/sparc/mm/io-unit.c linux-2.6.19-rc5_kzalloc/arch/sparc/mm/io-unit.c
--- linux-2.6.19-rc5_orig/arch/sparc/mm/io-unit.c 2006-11-09 12:16:21.000000000 +0200
+++ linux-2.6.19-rc5_kzalloc/arch/sparc/mm/io-unit.c 2006-11-11 22:44:04.000000000 +0200
@@ -41,9 +41,8 @@ iounit_init(int sbi_node, int io_node, s
struct linux_prom_registers iommu_promregs[PROMREG_MAX];
struct resource r;
- iounit = kmalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
+ iounit = kzalloc(sizeof(struct iounit_struct), GFP_ATOMIC);
- memset(iounit, 0, sizeof(*iounit));
iounit->limit[0] = IOUNIT_BMAP1_START;
iounit->limit[1] = IOUNIT_BMAP2_START;
iounit->limit[2] = IOUNIT_BMAPM_START;

...in this ^, the old code and your update don't check for NULL return.

Both of this parts are done at early stages, so it is probably:
a) Impossible to recover from failure
b) If you run out of memory at this stage, you are probably in very big trouble anyway

I could modify it to check and panic if the check fails.
Would that be better?

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