Re: [PATCH] x86/mm: lower MAP_32BIT begin to reduce heap collisions

[Dave Hansen]

On 8/25/25 03:48, Simon Liebold wrote:
> Commit 03475167fda5 ("x86: Increase brk randomness entropy for 64-bit
> systems") increased the brk randomness from 32 MiB to 1 GiB. MAP_32BIT
> looks between 1 GiB and 2 GiB for an unmapped area. Depending on the
> randomization, a heap starting high enough and being big enough can use
> up all the area that MAP_32BIT looks at, leading to allocation failures.

Isn't that still a really unreasonably gigantic heap?

Would you mind posting some actual /proc/$pid/maps output from one of
the failure cases?