On Thu, 2011-09-22 at 13:57 -0700, Colin Cross wrote:
> seq_files are often used for debugging. When things are going wrong
> due to failed physically contiguous allocations, the exponentially
> growing physically contiguous allocations in seq_read can make things
> worse. There is no need for physically contiguous memory, so switch
> to virtually contiguous memory instead.
vmalloc's are relatively expensive.
Perhaps use kmalloc when appropriate instead?
[]
> - /* don't ask for more than the kmalloc() max size */
> - if (size > KMALLOC_MAX_SIZE)
> - size = KMALLOC_MAX_SIZE;
> -
> - buf = kmalloc(size, GFP_KERNEL);
> + buf = vmalloc(size);
> if (!buf)
> return -ENOMEM;
if (size > KMALLOC_MAX_SIZE)
buf = vmalloc(size, GFP_KERNEL)
else
buf = kmalloc(size, GFP_KERNEL);
> + vfree(m->buf);
if (m->size > KMALLOC_MAX_SIZE)
vfree(m->buf);
else
kfree(m->buf);
> m->buf = buf;
> m->size = size;
>
> @@ -106,7 +103,7 @@ static int traverse(struct seq_file *m, loff_t offset)
> return 0;
> }
> if (!m->buf) {
> - m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
> + m->buf = vmalloc(m->size = PAGE_SIZE);
embedding the set of m->size like this is ugly.
[do the same as above kmalloc/vmalloc based on size]
etc.
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