Re: [PATCH v5 33/40] x86/resctrl: Drop __init/__exit on assorted symbols
From: Reinette Chatre
Date: Wed Oct 23 2024 - 19:57:27 EST
Hi James,
On 10/4/24 11:03 AM, James Morse wrote:
> Because ARM's MPAM controls are probed using MMIO, resctrl can't be
> initialised until enough CPUs are online to have determined the
> system-wide supported num_closid. Arm64 also supports 'late onlined
> secondaries', where only a subset of CPUs are online during boot.
>
> These two combine to mean the MPAM driver may not be able to initialise
> resctrl until user-space has brought 'enough' CPUs online.
>
> To allow MPAM to initialise resctrl after __init text has been free'd,
> remove all the __init markings from resctrl.
>
> The existing __exit markings cause these functions to be removed by the
> linker as it has never been possible to build resctrl as a module. MPAM
> has an error interrupt which causes the driver to reset and disable
> itself. Remove the __exit markings to allow the MPAM driver to tear down
> resctrl when an error occurs.
>
> Signed-off-by: James Morse <james.morse@xxxxxxx>
> Tested-by: Carl Worth <carl@xxxxxxxxxxxxxxxxxxxxxx> # arm64
> Tested-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@xxxxxxxxxxxxxx>
> ---
> Changes since v4:
> * Earlier __init marker removal migrated here.
> ---
> arch/x86/kernel/cpu/resctrl/core.c | 6 +++---
> arch/x86/kernel/cpu/resctrl/internal.h | 6 +++---
> arch/x86/kernel/cpu/resctrl/monitor.c | 2 +-
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 10 +++++-----
> include/linux/resctrl.h | 6 +++---
> 5 files changed, 15 insertions(+), 15 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
> index f484726a2588..f713ac628444 100644
> --- a/arch/x86/kernel/cpu/resctrl/core.c
> +++ b/arch/x86/kernel/cpu/resctrl/core.c
> @@ -775,7 +775,7 @@ struct rdt_options {
> bool force_off, force_on;
> };
>
> -static struct rdt_options rdt_options[] __initdata = {
> +static struct rdt_options rdt_options[] __ro_after_init = {
> RDT_OPT(RDT_FLAG_CMT, "cmt", X86_FEATURE_CQM_OCCUP_LLC),
> RDT_OPT(RDT_FLAG_MBM_TOTAL, "mbmtotal", X86_FEATURE_CQM_MBM_TOTAL),
> RDT_OPT(RDT_FLAG_MBM_LOCAL, "mbmlocal", X86_FEATURE_CQM_MBM_LOCAL),
> @@ -815,7 +815,7 @@ static int __init set_rdt_options(char *str)
> }
> __setup("rdt", set_rdt_options);
>
> -bool __init rdt_cpu_has(int flag)
> +bool rdt_cpu_has(int flag)
I assume this can be dropped when resctrl_arch_is_evt_configurable() uses
a helper instead?
Reinette