On Thu, 2010-05-13 at 17:51 +0800, Changli Gao wrote:
> +void *__kvmalloc(size_t size, gfp_t flags)
> +{
> + void *ptr;
> +
> + if (size < PAGE_SIZE)
> + return kmalloc(size, GFP_KERNEL | flags);
> + size = PAGE_ALIGN(size);
> + if (is_power_of_2(size))
> + ptr = (void *)__get_free_pages(GFP_KERNEL | flags |
> + __GFP_NOWARN, get_order(size));
> + else
> + ptr = alloc_pages_exact(size, GFP_KERNEL | flags |
> + __GFP_NOWARN);
> + if (ptr != NULL) {
> + virt_to_head_page(ptr)->private = size;
> + return ptr;
> + }
> +
> + ptr = vmalloc(size);
> + if (ptr != NULL && (flags & __GFP_ZERO))
> + memset(ptr, 0, size);
> +
> + return ptr;
> +}
> +EXPORT_SYMBOL(__kvmalloc);
So if I do kvmalloc(size, GFP_ATOMIC) I get GFP_KERNEL|GFP_ATOMIC, which
is not a recommended variation because one should not mix __GFP_WAIT and
__GFP_HIGH.
So I would simply drop the gfp argument to avoid confusion.
> +void __kvfree(void *ptr, bool inatomic)
> +{
> + if (unlikely(ZERO_OR_NULL_PTR(ptr)))
> + return;
> + if (is_vmalloc_addr(ptr)) {
> + if (inatomic) {
> + struct work_struct *work;
> +
> + work = ptr;
> + BUILD_BUG_ON(sizeof(struct work_struct) > PAGE_SIZE);
> + INIT_WORK(work, kvfree_work);
> + schedule_work(work);
> + } else {
> + vfree(ptr);
> + }
> + } else {
> + struct page *page;
> +
> + page = virt_to_head_page(ptr);
> + if (PageSlab(page) || PageCompound(page))
> + kfree(ptr);
> + else if (is_power_of_2(page->private))
> + free_pages((unsigned long)ptr,
> + get_order(page->private));
> + else
> + free_pages_exact(ptr, page->private);
> + }
> +}
> +EXPORT_SYMBOL(__kvfree);
NAK, I really utterly dislike that inatomic argument. The alloc side
doesn't function in atomic context either. Please keep the thing
symmetric in that regards.
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