Re: [RFC PATCH 34/56] x86/alternative: Save old bytes for alternatives

From: Nikolay Borisov

Date: Thu Oct 30 2025 - 11:43:02 EST




On 10/30/25 16:39, Kaplan, David wrote:
<snip>



Yes, there is an 8B pointer to each allocation (although I didn't include that in the number above).

There's a number of ways to optimize this, doing a single 'big buffer' with perhaps a 32-bit index seems rather straightforward. And maybe there are then further ways to squeeze this. But I think we're really talking about a small amount of memory, especially compared to the other overhead noted above.



I spoke with Vlastimil who's a lot more familiar with MM and he said that allocations made early in the boot are likely to fall within the same 2mb block so actually what we are discussing here might very well fall within "premature optimisation" land.



Thanks
--David Kaplan