Jan Beulich
2011-Oct-11 14:00 UTC
[Xen-devel] [PATCH] linux-2.6.18: streamline clearing of memory in a few places
- use kzalloc() in favor of kmalloc()+memset() in one more spot
- use clear_page() in favor of memset(, 0, PAGE_SIZE) (also use
copy_page() in favor of memcpy(, , PAGE_SIZE))
- don''t redundantly clear memory
Signed-off-by: Jan Beulich <jbeulich@suse.com>
--- a/arch/i386/mm/init-xen.c
+++ b/arch/i386/mm/init-xen.c
@@ -558,7 +558,7 @@ void __init paging_init(void)
* dummy page. */
set_fixmap(FIX_SHARED_INFO, xen_start_info->shared_info);
HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
- memset(empty_zero_page, 0, sizeof(empty_zero_page));
+ clear_page(empty_zero_page);
/* Setup mapping of lower 1st MB */
for (i = 0; i < NR_FIX_ISAMAPS; i++)
--- a/arch/x86_64/mm/init-xen.c
+++ b/arch/x86_64/mm/init-xen.c
@@ -218,7 +218,7 @@ static __init void *spp_getpage(void)
else if (start_pfn < table_end) {
ptr = __va(start_pfn << PAGE_SHIFT);
start_pfn++;
- memset(ptr, 0, PAGE_SIZE);
+ clear_page(ptr);
} else
ptr = alloc_bootmem_pages(PAGE_SIZE);
if (!ptr || ((unsigned long)ptr & ~PAGE_MASK))
@@ -376,7 +376,7 @@ static __meminit void *alloc_static_page
*phys = start_pfn << PAGE_SHIFT;
start_pfn++;
- memset((void *)va, 0, PAGE_SIZE);
+ clear_page((void *)va);
return (void *)va;
}
@@ -728,7 +728,7 @@ static void xen_finish_init_mapping(void
/* Switch to the real shared_info page, and clear the dummy page. */
set_fixmap(FIX_SHARED_INFO, xen_start_info->shared_info);
HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
- memset(empty_zero_page, 0, sizeof(empty_zero_page));
+ clear_page(empty_zero_page);
/* Set up mapping of lowest 1MB of physical memory. */
for (i = 0; i < NR_FIX_ISAMAPS; i++)
--- a/drivers/xen/core/gnttab.c
+++ b/drivers/xen/core/gnttab.c
@@ -543,7 +543,7 @@ int gnttab_copy_grant_page(grant_ref_t r
new_addr = page_address(new_page);
addr = page_address(page);
- memcpy(new_addr, addr, PAGE_SIZE);
+ copy_page(new_addr, addr);
pfn = page_to_pfn(page);
mfn = pfn_to_mfn(pfn);
--- a/drivers/xen/core/machine_reboot.c
+++ b/drivers/xen/core/machine_reboot.c
@@ -89,7 +89,7 @@ static void post_suspend(int suspend_can
BUG();
HYPERVISOR_shared_info = (shared_info_t *)fix_to_virt(FIX_SHARED_INFO);
- memset(empty_zero_page, 0, PAGE_SIZE);
+ clear_page(empty_zero_page);
fpp = PAGE_SIZE/sizeof(unsigned long);
for (i = 0, j = 0, k = -1; i < max_pfn; i += fpp, j++) {
--- a/drivers/xen/core/smpboot.c
+++ b/drivers/xen/core/smpboot.c
@@ -198,17 +198,12 @@ static void __cpuinit cpu_initialize_con
ctxt.flags = VGCF_IN_KERNEL;
ctxt.user_regs.ds = __USER_DS;
ctxt.user_regs.es = __USER_DS;
- ctxt.user_regs.fs = 0;
- ctxt.user_regs.gs = 0;
ctxt.user_regs.ss = __KERNEL_DS;
ctxt.user_regs.eip = (unsigned long)cpu_bringup_and_idle;
ctxt.user_regs.eflags = X86_EFLAGS_IF | 0x1000; /* IOPL_RING1 */
- memset(&ctxt.fpu_ctxt, 0, sizeof(ctxt.fpu_ctxt));
-
smp_trap_init(ctxt.trap_ctxt);
- ctxt.ldt_ents = 0;
ctxt.gdt_frames[0] = virt_to_mfn(gdt_descr->address);
ctxt.gdt_ents = gdt_descr->size / 8;
--- a/drivers/xen/netback/interface.c
+++ b/drivers/xen/netback/interface.c
@@ -236,7 +236,6 @@ netif_t *netif_alloc(struct device *pare
SET_NETDEV_DEV(dev, parent);
netif = netdev_priv(dev);
- memset(netif, 0, sizeof(*netif));
netif->domid = domid;
netif->handle = handle;
netif->can_sg = 1;
--- a/drivers/xen/sfc_netutil/accel_cuckoo_hash.c
+++ b/drivers/xen/sfc_netutil/accel_cuckoo_hash.c
@@ -76,7 +76,7 @@ int cuckoo_hash_init(cuckoo_hash_table *
BUG_ON(length_bits >= sizeof(unsigned) * 8);
BUG_ON(key_length > sizeof(cuckoo_hash_key));
- table_mem = kmalloc(sizeof(cuckoo_hash_entry) * 2 * length, GFP_KERNEL);
+ table_mem = kzalloc(sizeof(cuckoo_hash_entry) * 2 * length, GFP_KERNEL);
if (table_mem == NULL)
return -ENOMEM;
@@ -92,9 +92,6 @@ int cuckoo_hash_init(cuckoo_hash_table *
set_hash_parameters(hashtab);
- /* Zero the table */
- memset(hashtab->table0, 0, length * 2 * sizeof(cuckoo_hash_entry));
-
return 0;
}
EXPORT_SYMBOL_GPL(cuckoo_hash_init);
--- a/drivers/xen/tpmback/interface.c
+++ b/drivers/xen/tpmback/interface.c
@@ -93,7 +93,7 @@ int tpmif_map(tpmif_t *tpmif, grant_ref_
tpmif->tx_area = area;
tpmif->tx = (tpmif_tx_interface_t *)area->addr;
- memset(tpmif->tx, 0, PAGE_SIZE);
+ clear_page(tpmif->tx);
err = bind_interdomain_evtchn_to_irqhandler(
tpmif->domid, evtchn, tpmif_be_int, 0, tpmif->devname, tpmif);
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