x86/resctrl: Optimize some resctrl code

[PATCH 2/2] x86/resctrl: Optimize code in rdt_get_tree()

Posted by Shaopeng Tan 4 months ago

Inconsistent context format. Optimize it,
not only save a line and also make it easier to understand.

Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
---
 fs/resctrl/rdtgroup.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
index 1beb124e25f6..8bf87211eadb 100644
--- a/fs/resctrl/rdtgroup.c
+++ b/fs/resctrl/rdtgroup.c
@@ -2608,10 +2608,8 @@ static int rdt_get_tree(struct fs_context *fc)
 		goto out_root;
 
 	ret = schemata_list_create();
-	if (ret) {
-		schemata_list_destroy();
-		goto out_ctx;
-	}
+	if (ret)
+		goto out_schemata_free;
 
 	ret = closid_init();
 	if (ret)
-- 
2.43.5

Re: [PATCH 2/2] x86/resctrl: Optimize code in rdt_get_tree()

Posted by Reinette Chatre 4 months ago

Hi Shaopeng,

On 6/10/25 7:15 PM, Shaopeng Tan wrote:
> Inconsistent context format. Optimize it,

What does "Inconsistent context format" mean?

> not only save a line and also make it easier to understand.

The changelog needs to follow rules found in "Changelog"
section of Documentation/process/maintainer-tip.rst.

Here is an example:
	schemata_list_destroy() has to be called if
	schemata_list_create() fails.

	rdt_get_tree() calls schemata_list_destroy() in two different
	ways: directly if schemata_list_create() itself fails and on
	the exit path via the out_schemata_free goto label.                                           
                                                                                
	Remove schemata_list_destroy() call on schemata_list_create()
	failure. Use existing out_schemata_free goto label instead.

> 
> Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> ---
>  fs/resctrl/rdtgroup.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
> index 1beb124e25f6..8bf87211eadb 100644
> --- a/fs/resctrl/rdtgroup.c
> +++ b/fs/resctrl/rdtgroup.c
> @@ -2608,10 +2608,8 @@ static int rdt_get_tree(struct fs_context *fc)
>  		goto out_root;
>  
>  	ret = schemata_list_create();
> -	if (ret) {
> -		schemata_list_destroy();
> -		goto out_ctx;
> -	}
> +	if (ret)
> +		goto out_schemata_free;
>  
>  	ret = closid_init();
>  	if (ret)

Please address the issue of now unused "out_ctx" label reported
in [1]. Looks good to me otherwise.

Thank you for the cleanup.

Reinette

[1] https://lore.kernel.org/lkml/202506120440.lz9OAoXE-lkp@intel.com/

Re: [PATCH 2/2] x86/resctrl: Optimize code in rdt_get_tree()

Posted by Reinette Chatre 4 months ago

Hi Shaopeng,

One small follow-up ... since this is a resctrl fs change,
could you please switch prefix to be "fs/resctrl"?

Thank you

Reinette

Re: [PATCH 2/2] x86/resctrl: Optimize code in rdt_get_tree()

Posted by kernel test robot 4 months ago

Hi Shaopeng,

kernel test robot noticed the following build warnings:

[auto build test WARNING on tip/master]
[also build test WARNING on brauner-vfs/vfs.all linus/master v6.16-rc1 next-20250611]
[cannot apply to tip/auto-latest bp/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Shaopeng-Tan/x86-resctrl-Remove-unnecessary-cpumask_nth_andnot/20250611-104547
base:   tip/master
patch link:    https://lore.kernel.org/r/20250611021547.2766889-3-tan.shaopeng%40jp.fujitsu.com
patch subject: [PATCH 2/2] x86/resctrl: Optimize code in rdt_get_tree()
config: x86_64-randconfig-002-20250612 (https://download.01.org/0day-ci/archive/20250612/202506120440.lz9OAoXE-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250612/202506120440.lz9OAoXE-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202506120440.lz9OAoXE-lkp@intel.com/

All warnings (new ones prefixed by >>):

   fs/resctrl/rdtgroup.c: In function 'rdt_get_tree':
>> fs/resctrl/rdtgroup.c:2684:1: warning: label 'out_ctx' defined but not used [-Wunused-label]
    2684 | out_ctx:
         | ^~~~~~~


vim +/out_ctx +2684 fs/resctrl/rdtgroup.c

7168ae330e8105 James Morse  2025-05-15  2583  
7168ae330e8105 James Morse  2025-05-15  2584  static int rdt_get_tree(struct fs_context *fc)
7168ae330e8105 James Morse  2025-05-15  2585  {
7168ae330e8105 James Morse  2025-05-15  2586  	struct rdt_fs_context *ctx = rdt_fc2context(fc);
7168ae330e8105 James Morse  2025-05-15  2587  	unsigned long flags = RFTYPE_CTRL_BASE;
7168ae330e8105 James Morse  2025-05-15  2588  	struct rdt_mon_domain *dom;
7168ae330e8105 James Morse  2025-05-15  2589  	struct rdt_resource *r;
7168ae330e8105 James Morse  2025-05-15  2590  	int ret;
7168ae330e8105 James Morse  2025-05-15  2591  
7168ae330e8105 James Morse  2025-05-15  2592  	cpus_read_lock();
7168ae330e8105 James Morse  2025-05-15  2593  	mutex_lock(&rdtgroup_mutex);
7168ae330e8105 James Morse  2025-05-15  2594  	/*
7168ae330e8105 James Morse  2025-05-15  2595  	 * resctrl file system can only be mounted once.
7168ae330e8105 James Morse  2025-05-15  2596  	 */
7168ae330e8105 James Morse  2025-05-15  2597  	if (resctrl_mounted) {
7168ae330e8105 James Morse  2025-05-15  2598  		ret = -EBUSY;
7168ae330e8105 James Morse  2025-05-15  2599  		goto out;
7168ae330e8105 James Morse  2025-05-15  2600  	}
7168ae330e8105 James Morse  2025-05-15  2601  
7168ae330e8105 James Morse  2025-05-15  2602  	ret = rdtgroup_setup_root(ctx);
7168ae330e8105 James Morse  2025-05-15  2603  	if (ret)
7168ae330e8105 James Morse  2025-05-15  2604  		goto out;
7168ae330e8105 James Morse  2025-05-15  2605  
7168ae330e8105 James Morse  2025-05-15  2606  	ret = rdt_enable_ctx(ctx);
7168ae330e8105 James Morse  2025-05-15  2607  	if (ret)
7168ae330e8105 James Morse  2025-05-15  2608  		goto out_root;
7168ae330e8105 James Morse  2025-05-15  2609  
7168ae330e8105 James Morse  2025-05-15  2610  	ret = schemata_list_create();
b67b139e5b652e Shaopeng Tan 2025-06-11  2611  	if (ret)
b67b139e5b652e Shaopeng Tan 2025-06-11  2612  		goto out_schemata_free;
7168ae330e8105 James Morse  2025-05-15  2613  
7168ae330e8105 James Morse  2025-05-15  2614  	ret = closid_init();
7168ae330e8105 James Morse  2025-05-15  2615  	if (ret)
7168ae330e8105 James Morse  2025-05-15  2616  		goto out_schemata_free;
7168ae330e8105 James Morse  2025-05-15  2617  
7168ae330e8105 James Morse  2025-05-15  2618  	if (resctrl_arch_mon_capable())
7168ae330e8105 James Morse  2025-05-15  2619  		flags |= RFTYPE_MON;
7168ae330e8105 James Morse  2025-05-15  2620  
7168ae330e8105 James Morse  2025-05-15  2621  	ret = rdtgroup_add_files(rdtgroup_default.kn, flags);
7168ae330e8105 James Morse  2025-05-15  2622  	if (ret)
7168ae330e8105 James Morse  2025-05-15  2623  		goto out_closid_exit;
7168ae330e8105 James Morse  2025-05-15  2624  
7168ae330e8105 James Morse  2025-05-15  2625  	kernfs_activate(rdtgroup_default.kn);
7168ae330e8105 James Morse  2025-05-15  2626  
7168ae330e8105 James Morse  2025-05-15  2627  	ret = rdtgroup_create_info_dir(rdtgroup_default.kn);
7168ae330e8105 James Morse  2025-05-15  2628  	if (ret < 0)
7168ae330e8105 James Morse  2025-05-15  2629  		goto out_closid_exit;
7168ae330e8105 James Morse  2025-05-15  2630  
7168ae330e8105 James Morse  2025-05-15  2631  	if (resctrl_arch_mon_capable()) {
7168ae330e8105 James Morse  2025-05-15  2632  		ret = mongroup_create_dir(rdtgroup_default.kn,
7168ae330e8105 James Morse  2025-05-15  2633  					  &rdtgroup_default, "mon_groups",
7168ae330e8105 James Morse  2025-05-15  2634  					  &kn_mongrp);
7168ae330e8105 James Morse  2025-05-15  2635  		if (ret < 0)
7168ae330e8105 James Morse  2025-05-15  2636  			goto out_info;
7168ae330e8105 James Morse  2025-05-15  2637  
7168ae330e8105 James Morse  2025-05-15  2638  		ret = mkdir_mondata_all(rdtgroup_default.kn,
7168ae330e8105 James Morse  2025-05-15  2639  					&rdtgroup_default, &kn_mondata);
7168ae330e8105 James Morse  2025-05-15  2640  		if (ret < 0)
7168ae330e8105 James Morse  2025-05-15  2641  			goto out_mongrp;
7168ae330e8105 James Morse  2025-05-15  2642  		rdtgroup_default.mon.mon_data_kn = kn_mondata;
7168ae330e8105 James Morse  2025-05-15  2643  	}
7168ae330e8105 James Morse  2025-05-15  2644  
7168ae330e8105 James Morse  2025-05-15  2645  	ret = rdt_pseudo_lock_init();
7168ae330e8105 James Morse  2025-05-15  2646  	if (ret)
7168ae330e8105 James Morse  2025-05-15  2647  		goto out_mondata;
7168ae330e8105 James Morse  2025-05-15  2648  
7168ae330e8105 James Morse  2025-05-15  2649  	ret = kernfs_get_tree(fc);
7168ae330e8105 James Morse  2025-05-15  2650  	if (ret < 0)
7168ae330e8105 James Morse  2025-05-15  2651  		goto out_psl;
7168ae330e8105 James Morse  2025-05-15  2652  
7168ae330e8105 James Morse  2025-05-15  2653  	if (resctrl_arch_alloc_capable())
7168ae330e8105 James Morse  2025-05-15  2654  		resctrl_arch_enable_alloc();
7168ae330e8105 James Morse  2025-05-15  2655  	if (resctrl_arch_mon_capable())
7168ae330e8105 James Morse  2025-05-15  2656  		resctrl_arch_enable_mon();
7168ae330e8105 James Morse  2025-05-15  2657  
7168ae330e8105 James Morse  2025-05-15  2658  	if (resctrl_arch_alloc_capable() || resctrl_arch_mon_capable())
7168ae330e8105 James Morse  2025-05-15  2659  		resctrl_mounted = true;
7168ae330e8105 James Morse  2025-05-15  2660  
7168ae330e8105 James Morse  2025-05-15  2661  	if (resctrl_is_mbm_enabled()) {
7168ae330e8105 James Morse  2025-05-15  2662  		r = resctrl_arch_get_resource(RDT_RESOURCE_L3);
7168ae330e8105 James Morse  2025-05-15  2663  		list_for_each_entry(dom, &r->mon_domains, hdr.list)
7168ae330e8105 James Morse  2025-05-15  2664  			mbm_setup_overflow_handler(dom, MBM_OVERFLOW_INTERVAL,
7168ae330e8105 James Morse  2025-05-15  2665  						   RESCTRL_PICK_ANY_CPU);
7168ae330e8105 James Morse  2025-05-15  2666  	}
7168ae330e8105 James Morse  2025-05-15  2667  
7168ae330e8105 James Morse  2025-05-15  2668  	goto out;
7168ae330e8105 James Morse  2025-05-15  2669  
7168ae330e8105 James Morse  2025-05-15  2670  out_psl:
7168ae330e8105 James Morse  2025-05-15  2671  	rdt_pseudo_lock_release();
7168ae330e8105 James Morse  2025-05-15  2672  out_mondata:
7168ae330e8105 James Morse  2025-05-15  2673  	if (resctrl_arch_mon_capable())
7168ae330e8105 James Morse  2025-05-15  2674  		kernfs_remove(kn_mondata);
7168ae330e8105 James Morse  2025-05-15  2675  out_mongrp:
7168ae330e8105 James Morse  2025-05-15  2676  	if (resctrl_arch_mon_capable())
7168ae330e8105 James Morse  2025-05-15  2677  		kernfs_remove(kn_mongrp);
7168ae330e8105 James Morse  2025-05-15  2678  out_info:
7168ae330e8105 James Morse  2025-05-15  2679  	kernfs_remove(kn_info);
7168ae330e8105 James Morse  2025-05-15  2680  out_closid_exit:
7168ae330e8105 James Morse  2025-05-15  2681  	closid_exit();
7168ae330e8105 James Morse  2025-05-15  2682  out_schemata_free:
7168ae330e8105 James Morse  2025-05-15  2683  	schemata_list_destroy();
7168ae330e8105 James Morse  2025-05-15 @2684  out_ctx:
7168ae330e8105 James Morse  2025-05-15  2685  	rdt_disable_ctx();
7168ae330e8105 James Morse  2025-05-15  2686  out_root:
7168ae330e8105 James Morse  2025-05-15  2687  	rdtgroup_destroy_root();
7168ae330e8105 James Morse  2025-05-15  2688  out:
7168ae330e8105 James Morse  2025-05-15  2689  	rdt_last_cmd_clear();
7168ae330e8105 James Morse  2025-05-15  2690  	mutex_unlock(&rdtgroup_mutex);
7168ae330e8105 James Morse  2025-05-15  2691  	cpus_read_unlock();
7168ae330e8105 James Morse  2025-05-15  2692  	return ret;
7168ae330e8105 James Morse  2025-05-15  2693  }
7168ae330e8105 James Morse  2025-05-15  2694  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki