On Mon, Dec 01, 2008 at 07:45:14PM +0300, Alexey Starikovskiy wrote: > Nick Piggin wrote: > >On Mon, Dec 01, 2008 at 05:02:50PM +0300, Alexey Starikovskiy wrote: > > > >>Because SLAB has standard memory wells of 2^x size. None of cached ACPI > >>objects has exactly this size, so bigger block will be used. Plus, > >>internal ACPICA caching will add some overhead. > >> > > > >That's an insane looking caching thing now that I come to closely read > >the code. There is so much stuff there that I thought it must have been > >doing something useful which is why I didn't replace the Linux functions > >with kmalloc/kfree directly. > > > >There is really some operating system you support that has such a poor > >allocator that you think ACPI can do better in 300 lines of code? Why > >not just rip that whole thing out? > > > You would laugh, this is due to Windows userspace debug library -- it > checks for > memory leaks by default, and it takes ages to do this. OK... circumvent the debug library? :) I won't argue. But I agree it is wrong for Linux so my patch is not good. It needs to use kmalloc at least. > And ACPICA maintainer is sitting on Windows, so he _cares_. > >>Do you have another interpreter in kernel space? > >> > > > >So what makes it special? > > > > > You don't know what size of program you will end up with. > DSDT could be almost empty, or you could have several thousand of SSDT > tables. OK. And I guess the sizes of the objects seem to be variable as well. I still think kmalloc would be fine, and would save memory in some situations. On tiny systems it is less likely to because each slab costs less memory. On a big system, the caches can take some MB each in some configurations. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
