gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/sentry/fsimpl/cgroupfs/cpu.go (about)

     1  // Copyright 2021 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package cgroupfs
    16  
    17  import (
    18  	"gvisor.dev/gvisor/pkg/atomicbitops"
    19  	"gvisor.dev/gvisor/pkg/context"
    20  	"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
    21  	"gvisor.dev/gvisor/pkg/sentry/kernel"
    22  	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
    23  )
    24  
    25  // +stateify savable
    26  type cpuController struct {
    27  	controllerCommon
    28  	controllerStateless
    29  	controllerNoResource
    30  
    31  	// CFS bandwidth control parameters, values in microseconds.
    32  	cfsPeriod atomicbitops.Int64
    33  	cfsQuota  atomicbitops.Int64
    34  
    35  	// CPU shares, values should be (num core * 1024).
    36  	shares atomicbitops.Int64
    37  }
    38  
    39  var _ controller = (*cpuController)(nil)
    40  
    41  func newCPUController(fs *filesystem, defaults map[string]int64) *cpuController {
    42  	// Default values for controller parameters from Linux.
    43  	c := &cpuController{
    44  		cfsPeriod: atomicbitops.FromInt64(100000),
    45  		cfsQuota:  atomicbitops.FromInt64(-1),
    46  		shares:    atomicbitops.FromInt64(1024),
    47  	}
    48  
    49  	if val, ok := defaults["cpu.cfs_period_us"]; ok {
    50  		c.cfsPeriod = atomicbitops.FromInt64(val)
    51  		delete(defaults, "cpu.cfs_period_us")
    52  	}
    53  	if val, ok := defaults["cpu.cfs_quota_us"]; ok {
    54  		c.cfsQuota = atomicbitops.FromInt64(val)
    55  		delete(defaults, "cpu.cfs_quota_us")
    56  	}
    57  	if val, ok := defaults["cpu.shares"]; ok {
    58  		c.shares = atomicbitops.FromInt64(val)
    59  		delete(defaults, "cpu.shares")
    60  	}
    61  
    62  	c.controllerCommon.init(kernel.CgroupControllerCPU, fs)
    63  	return c
    64  }
    65  
    66  // Clone implements controller.Clone.
    67  func (c *cpuController) Clone() controller {
    68  	new := &cpuController{
    69  		cfsPeriod: atomicbitops.FromInt64(c.cfsPeriod.Load()),
    70  		cfsQuota:  atomicbitops.FromInt64(c.cfsQuota.Load()),
    71  		shares:    atomicbitops.FromInt64(c.shares.Load()),
    72  	}
    73  	new.controllerCommon.cloneFromParent(c)
    74  	return new
    75  }
    76  
    77  // AddControlFiles implements controller.AddControlFiles.
    78  func (c *cpuController) AddControlFiles(ctx context.Context, creds *auth.Credentials, _ *cgroupInode, contents map[string]kernfs.Inode) {
    79  	contents["cpu.cfs_period_us"] = c.fs.newStubControllerFile(ctx, creds, &c.cfsPeriod, true)
    80  	contents["cpu.cfs_quota_us"] = c.fs.newStubControllerFile(ctx, creds, &c.cfsQuota, true)
    81  	contents["cpu.shares"] = c.fs.newStubControllerFile(ctx, creds, &c.shares, true)
    82  }