> Am 03.09.2025 um 17:48 schrieb Jan Hubicka <[email protected]>:
>
> Hi,
> the number of LTO partitions should exceed number of CPUs (or hyper-threads)
> of
> commonly used CPUs.
Commonly used. But yes, exceeds is quite relative ;). I guess it’s more like
exceeding the maximum number of threads seen on server platforms (with 2
CPU’s?).
> I think it is time to increase it again and as discussed
> in the LTO and toplevel asm thread, doing so scales quite well. Tmp file usage
> grows from 2.7 to 2.9MB which seems acceptable. Overall build time on machine
> with 256 hyperthreads is comparable.
>
> Bootstrapped/regtested x86_64-linux, comitted.
>
> gcc/ChangeLog:
>
> * params.opt (-param=lto-partitions=): INcrease default value from 128 to
> 512.
>
> diff --git a/gcc/params.opt b/gcc/params.opt
> index ac1b2c7eb26..dd53d830895 100644
> --- a/gcc/params.opt
> +++ b/gcc/params.opt
> @@ -462,7 +462,7 @@ Common Joined UInteger Var(param_min_partition_size)
> Init(10000) Param
> Minimal size of a partition for LTO (in estimated instructions).
>
> -param=lto-partitions=
> -Common Joined UInteger Var(param_lto_partitions) Init(128) IntegerRange(1,
> 65536) Param
> +Common Joined UInteger Var(param_lto_partitions) Init(512) IntegerRange(1,
> 65536) Param
> Number of partitions the program should be split to.
>
> Enum
