Add initial patches for CPU Controller on Control Group v2

This commit is contained in:
Shea Levy 2016-08-25 13:01:40 -04:00
parent d378f5fe11
commit 2b1fa9da8b
7 changed files with 1260 additions and 0 deletions

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@ -0,0 +1,407 @@
commit e7cae741f6d645ac68fe8823ca6ef45dbbf6891b
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Misc preps for cgroup unified hierarchy interface
Make the following changes in preparation for the cpu controller
interface implementation for the unified hierarchy. This patch
doesn't cause any functional differences.
* s/cpu_stats_show()/cpu_cfs_stats_show()/
* s/cpu_files/cpu_legacy_files/
* Separate out cpuacct_stats_read() from cpuacct_stats_show(). While
at it, remove pointless cpuacct_stat_desc[] array.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 732e993..77f3ddd 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8512,7 +8512,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret;
}
-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
{
struct task_group *tg = css_tg(seq_css(sf));
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
@@ -8552,7 +8552,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
}
#endif /* CONFIG_RT_GROUP_SCHED */
-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
@@ -8573,7 +8573,7 @@ static struct cftype cpu_files[] = {
},
{
.name = "stat",
- .seq_show = cpu_stats_show,
+ .seq_show = cpu_cfs_stats_show,
},
#endif
#ifdef CONFIG_RT_GROUP_SCHED
@@ -8599,7 +8599,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.fork = cpu_cgroup_fork,
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
- .legacy_cftypes = cpu_files,
+ .legacy_cftypes = cpu_legacy_files,
.early_init = 1,
};
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index dd7cbb5..42b2dd5 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -177,36 +177,33 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
return 0;
}
-static const char * const cpuacct_stat_desc[] = {
- [CPUACCT_STAT_USER] = "user",
- [CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca, u64 *userp, u64 *sysp)
{
- struct cpuacct *ca = css_ca(seq_css(sf));
int cpu;
- s64 val = 0;
+ *userp = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_USER];
- val += kcpustat->cpustat[CPUTIME_NICE];
+ *userp += kcpustat->cpustat[CPUTIME_USER];
+ *userp += kcpustat->cpustat[CPUTIME_NICE];
}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
- val = 0;
+ *sysp = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_SYSTEM];
- val += kcpustat->cpustat[CPUTIME_IRQ];
- val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SYSTEM];
+ *sysp += kcpustat->cpustat[CPUTIME_IRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SOFTIRQ];
}
+}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+ cputime64_t user, sys;
+ cpuacct_stats_read(css_ca(seq_css(sf)), &user, &sys);
+ seq_printf(sf, "user %lld\n", cputime64_to_clock_t(user));
+ seq_printf(sf, "system %lld\n", cputime64_to_clock_t(sys));
return 0;
}
commit 1bb33e8a69f089f2d3f58a0e681d4ff352e11c97
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Implement interface for cgroup unified hierarchy
While the cpu controller doesn't have any functional problems, there
are a couple interface issues which can be addressed in the v2
interface.
* cpuacct being a separate controller. This separation is artificial
and rather pointless as demonstrated by most use cases co-mounting
the two controllers. It also forces certain information to be
accounted twice.
* Use of different time units. Writable control knobs use
microseconds, some stat fields use nanoseconds while other cpuacct
stat fields use centiseconds.
* Control knobs which can't be used in the root cgroup still show up
in the root.
* Control knob names and semantics aren't consistent with other
controllers.
This patchset implements cpu controller's interface on the unified
hierarchy which adheres to the controller file conventions described
in Documentation/cgroups/unified-hierarchy.txt. Overall, the
following changes are made.
* cpuacct is implictly enabled and disabled by cpu and its information
is reported through "cpu.stat" which now uses microseconds for all
time durations. All time duration fields now have "_usec" appended
to them for clarity. While this doesn't solve the double accounting
immediately, once majority of users switch to v2, cpu can directly
account and report the relevant stats and cpuacct can be disabled on
the unified hierarchy.
Note that cpuacct.usage_percpu is currently not included in
"cpu.stat". If this information is actually called for, it can be
added later.
* "cpu.shares" is replaced with "cpu.weight" and operates on the
standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
The weight is scaled to scheduler weight so that 100 maps to 1024
and the ratio relationship is preserved - if weight is W and its
scaled value is S, W / 100 == S / 1024. While the mapped range is a
bit smaller than the orignal scheduler weight range, the dead zones
on both sides are relatively small and covers wider range than the
nice value mappings. This file doesn't make sense in the root
cgroup and isn't create on root.
* "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
which contains both quota and period.
* "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
"cpu.rt.max" which contains both runtime and period.
v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
CFS bandwidth stats and also using raw division for u64. Use
CONFIG_CFS_BANDWITH and do_div() instead.
The semantics of "cpu.rt.max" is not fully decided yet. Dropped
for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 77f3ddd..7aafe63 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8591,6 +8591,139 @@ static struct cftype cpu_legacy_files[] = {
{ } /* terminate */
};
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+ cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ struct task_group *tg = css_tg(seq_css(sf));
+ struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ u64 throttled_usec;
+
+ throttled_usec = cfs_b->throttled_time;
+ do_div(throttled_usec, NSEC_PER_USEC);
+
+ seq_printf(sf, "nr_periods %d\n"
+ "nr_throttled %d\n"
+ "throttled_usec %llu\n",
+ cfs_b->nr_periods, cfs_b->nr_throttled,
+ throttled_usec);
+ }
+#endif
+ return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct task_group *tg = css_tg(css);
+ u64 weight = scale_load_down(tg->shares);
+
+ return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 weight)
+{
+ /*
+ * cgroup weight knobs should use the common MIN, DFL and MAX
+ * values which are 1, 100 and 10000 respectively. While it loses
+ * a bit of range on both ends, it maps pretty well onto the shares
+ * value used by scheduler and the round-trip conversions preserve
+ * the original value over the entire range.
+ */
+ if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+ return -ERANGE;
+
+ weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+ return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+ long period, long quota)
+{
+ if (quota < 0)
+ seq_puts(sf, "max");
+ else
+ seq_printf(sf, "%ld", quota);
+
+ seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+ u64 *periodp, u64 *quotap)
+{
+ char tok[21]; /* U64_MAX */
+
+ if (!sscanf(buf, "%s %llu", tok, periodp))
+ return -EINVAL;
+
+ *periodp *= NSEC_PER_USEC;
+
+ if (sscanf(tok, "%llu", quotap))
+ *quotap *= NSEC_PER_USEC;
+ else if (!strcmp(tok, "max"))
+ *quotap = RUNTIME_INF;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+ struct task_group *tg = css_tg(seq_css(sf));
+
+ cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+ return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct task_group *tg = css_tg(of_css(of));
+ u64 period = tg_get_cfs_period(tg);
+ u64 quota;
+ int ret;
+
+ ret = cpu_period_quota_parse(buf, &period, &quota);
+ if (!ret)
+ ret = tg_set_cfs_bandwidth(tg, period, quota);
+ return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+ {
+ .name = "stat",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_stats_show,
+ },
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_weight_read_u64,
+ .write_u64 = cpu_weight_write_u64,
+ },
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_max_show,
+ .write = cpu_max_write,
+ },
+#endif
+ { } /* terminate */
+};
+
struct cgroup_subsys cpu_cgrp_subsys = {
.css_alloc = cpu_cgroup_css_alloc,
.css_free = cpu_cgroup_css_free,
@@ -8600,7 +8733,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.legacy_cftypes = cpu_legacy_files,
+ .dfl_cftypes = cpu_files,
.early_init = 1,
+#ifdef CONFIG_CGROUP_CPUACCT
+ /*
+ * cpuacct is enabled together with cpu on the unified hierarchy
+ * and its stats are reported through "cpu.stat".
+ */
+ .depends_on = 1 << cpuacct_cgrp_id,
+#endif
};
#endif /* CONFIG_CGROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 42b2dd5..b4d32a6 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -224,6 +224,30 @@ static struct cftype files[] = {
{ } /* terminate */
};
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+ struct cgroup_subsys_state *css;
+ u64 usage, user, sys;
+
+ css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+ usage = cpuusage_read(css, seq_cft(sf));
+ cpuacct_stats_read(css_ca(css), &user, &sys);
+
+ user *= TICK_NSEC;
+ sys *= TICK_NSEC;
+ do_div(usage, NSEC_PER_USEC);
+ do_div(user, NSEC_PER_USEC);
+ do_div(sys, NSEC_PER_USEC);
+
+ seq_printf(sf, "usage_usec %llu\n"
+ "user_usec %llu\n"
+ "system_usec %llu\n", usage, user, sys);
+
+ css_put(css);
+}
+
/*
* charge this task's execution time to its accounting group.
*
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index ed60562..44eace9 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -2,6 +2,7 @@
extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
extern void cpuacct_account_field(struct task_struct *p, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
#else
@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *p, int index, u64 val)
{
}
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
#endif

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@ -0,0 +1,407 @@
commit 6426c5b02d4aab620219b08a5d97ad8851b56b0d
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Misc preps for cgroup unified hierarchy interface
Make the following changes in preparation for the cpu controller
interface implementation for the unified hierarchy. This patch
doesn't cause any functional differences.
* s/cpu_stats_show()/cpu_cfs_stats_show()/
* s/cpu_files/cpu_legacy_files/
* Separate out cpuacct_stats_read() from cpuacct_stats_show(). While
at it, remove pointless cpuacct_stat_desc[] array.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d1f7149..0d34f35 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8371,7 +8371,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret;
}
-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
{
struct task_group *tg = css_tg(seq_css(sf));
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
@@ -8411,7 +8411,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
}
#endif /* CONFIG_RT_GROUP_SCHED */
-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
@@ -8432,7 +8432,7 @@ static struct cftype cpu_files[] = {
},
{
.name = "stat",
- .seq_show = cpu_stats_show,
+ .seq_show = cpu_cfs_stats_show,
},
#endif
#ifdef CONFIG_RT_GROUP_SCHED
@@ -8457,7 +8457,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.fork = cpu_cgroup_fork,
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
- .legacy_cftypes = cpu_files,
+ .legacy_cftypes = cpu_legacy_files,
.early_init = true,
};
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 4a81120..b99030a 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -180,36 +180,33 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
return 0;
}
-static const char * const cpuacct_stat_desc[] = {
- [CPUACCT_STAT_USER] = "user",
- [CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca, u64 *userp, u64 *sysp)
{
- struct cpuacct *ca = css_ca(seq_css(sf));
int cpu;
- s64 val = 0;
+ *userp = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_USER];
- val += kcpustat->cpustat[CPUTIME_NICE];
+ *userp += kcpustat->cpustat[CPUTIME_USER];
+ *userp += kcpustat->cpustat[CPUTIME_NICE];
}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
- val = 0;
+ *sysp = 0;
for_each_online_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_SYSTEM];
- val += kcpustat->cpustat[CPUTIME_IRQ];
- val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SYSTEM];
+ *sysp += kcpustat->cpustat[CPUTIME_IRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SOFTIRQ];
}
+}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+ cputime64_t user, sys;
+ cpuacct_stats_read(css_ca(seq_css(sf)), &user, &sys);
+ seq_printf(sf, "user %lld\n", cputime64_to_clock_t(user));
+ seq_printf(sf, "system %lld\n", cputime64_to_clock_t(sys));
return 0;
}
commit d2a799f795a5d5a69c9dc365c34f926e0649f840
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Implement interface for cgroup unified hierarchy
While the cpu controller doesn't have any functional problems, there
are a couple interface issues which can be addressed in the v2
interface.
* cpuacct being a separate controller. This separation is artificial
and rather pointless as demonstrated by most use cases co-mounting
the two controllers. It also forces certain information to be
accounted twice.
* Use of different time units. Writable control knobs use
microseconds, some stat fields use nanoseconds while other cpuacct
stat fields use centiseconds.
* Control knobs which can't be used in the root cgroup still show up
in the root.
* Control knob names and semantics aren't consistent with other
controllers.
This patchset implements cpu controller's interface on the unified
hierarchy which adheres to the controller file conventions described
in Documentation/cgroups/unified-hierarchy.txt. Overall, the
following changes are made.
* cpuacct is implictly enabled and disabled by cpu and its information
is reported through "cpu.stat" which now uses microseconds for all
time durations. All time duration fields now have "_usec" appended
to them for clarity. While this doesn't solve the double accounting
immediately, once majority of users switch to v2, cpu can directly
account and report the relevant stats and cpuacct can be disabled on
the unified hierarchy.
Note that cpuacct.usage_percpu is currently not included in
"cpu.stat". If this information is actually called for, it can be
added later.
* "cpu.shares" is replaced with "cpu.weight" and operates on the
standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
The weight is scaled to scheduler weight so that 100 maps to 1024
and the ratio relationship is preserved - if weight is W and its
scaled value is S, W / 100 == S / 1024. While the mapped range is a
bit smaller than the orignal scheduler weight range, the dead zones
on both sides are relatively small and covers wider range than the
nice value mappings. This file doesn't make sense in the root
cgroup and isn't create on root.
* "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
which contains both quota and period.
* "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
"cpu.rt.max" which contains both runtime and period.
v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
CFS bandwidth stats and also using raw division for u64. Use
CONFIG_CFS_BANDWITH and do_div() instead.
The semantics of "cpu.rt.max" is not fully decided yet. Dropped
for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 0d34f35..5990efc 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8450,6 +8450,139 @@ static struct cftype cpu_legacy_files[] = {
{ } /* terminate */
};
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+ cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ struct task_group *tg = css_tg(seq_css(sf));
+ struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ u64 throttled_usec;
+
+ throttled_usec = cfs_b->throttled_time;
+ do_div(throttled_usec, NSEC_PER_USEC);
+
+ seq_printf(sf, "nr_periods %d\n"
+ "nr_throttled %d\n"
+ "throttled_usec %llu\n",
+ cfs_b->nr_periods, cfs_b->nr_throttled,
+ throttled_usec);
+ }
+#endif
+ return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct task_group *tg = css_tg(css);
+ u64 weight = scale_load_down(tg->shares);
+
+ return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 weight)
+{
+ /*
+ * cgroup weight knobs should use the common MIN, DFL and MAX
+ * values which are 1, 100 and 10000 respectively. While it loses
+ * a bit of range on both ends, it maps pretty well onto the shares
+ * value used by scheduler and the round-trip conversions preserve
+ * the original value over the entire range.
+ */
+ if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+ return -ERANGE;
+
+ weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+ return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+ long period, long quota)
+{
+ if (quota < 0)
+ seq_puts(sf, "max");
+ else
+ seq_printf(sf, "%ld", quota);
+
+ seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+ u64 *periodp, u64 *quotap)
+{
+ char tok[21]; /* U64_MAX */
+
+ if (!sscanf(buf, "%s %llu", tok, periodp))
+ return -EINVAL;
+
+ *periodp *= NSEC_PER_USEC;
+
+ if (sscanf(tok, "%llu", quotap))
+ *quotap *= NSEC_PER_USEC;
+ else if (!strcmp(tok, "max"))
+ *quotap = RUNTIME_INF;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+ struct task_group *tg = css_tg(seq_css(sf));
+
+ cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+ return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct task_group *tg = css_tg(of_css(of));
+ u64 period = tg_get_cfs_period(tg);
+ u64 quota;
+ int ret;
+
+ ret = cpu_period_quota_parse(buf, &period, &quota);
+ if (!ret)
+ ret = tg_set_cfs_bandwidth(tg, period, quota);
+ return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+ {
+ .name = "stat",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_stats_show,
+ },
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_weight_read_u64,
+ .write_u64 = cpu_weight_write_u64,
+ },
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_max_show,
+ .write = cpu_max_write,
+ },
+#endif
+ { } /* terminate */
+};
+
struct cgroup_subsys cpu_cgrp_subsys = {
.css_alloc = cpu_cgroup_css_alloc,
.css_released = cpu_cgroup_css_released,
@@ -8458,7 +8591,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.legacy_cftypes = cpu_legacy_files,
+ .dfl_cftypes = cpu_files,
.early_init = true,
+#ifdef CONFIG_CGROUP_CPUACCT
+ /*
+ * cpuacct is enabled together with cpu on the unified hierarchy
+ * and its stats are reported through "cpu.stat".
+ */
+ .depends_on = 1 << cpuacct_cgrp_id,
+#endif
};
#endif /* CONFIG_CGROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index b99030a..a1a5a4b 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -227,6 +227,30 @@ static struct cftype files[] = {
{ } /* terminate */
};
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+ struct cgroup_subsys_state *css;
+ u64 usage, user, sys;
+
+ css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+ usage = cpuusage_read(css, seq_cft(sf));
+ cpuacct_stats_read(css_ca(css), &user, &sys);
+
+ user *= TICK_NSEC;
+ sys *= TICK_NSEC;
+ do_div(usage, NSEC_PER_USEC);
+ do_div(user, NSEC_PER_USEC);
+ do_div(sys, NSEC_PER_USEC);
+
+ seq_printf(sf, "usage_usec %llu\n"
+ "user_usec %llu\n"
+ "system_usec %llu\n", usage, user, sys);
+
+ css_put(css);
+}
+
/*
* charge this task's execution time to its accounting group.
*
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index ba72807..ddf7af4 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -2,6 +2,7 @@
extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
#else
@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
{
}
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
#endif

View File

@ -0,0 +1,407 @@
commit 0d966df508ef4d6c0b1baae9e369f4fb0d3e10af
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Misc preps for cgroup unified hierarchy interface
Make the following changes in preparation for the cpu controller
interface implementation for the unified hierarchy. This patch
doesn't cause any functional differences.
* s/cpu_stats_show()/cpu_cfs_stats_show()/
* s/cpu_files/cpu_legacy_files/
* Separate out cpuacct_stats_read() from cpuacct_stats_show(). While
at it, remove pointless cpuacct_stat_desc[] array.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 97ee9ac..c148dfe 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8482,7 +8482,7 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret;
}
-static int cpu_stats_show(struct seq_file *sf, void *v)
+static int cpu_cfs_stats_show(struct seq_file *sf, void *v)
{
struct task_group *tg = css_tg(seq_css(sf));
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
@@ -8522,7 +8522,7 @@ static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css,
}
#endif /* CONFIG_RT_GROUP_SCHED */
-static struct cftype cpu_files[] = {
+static struct cftype cpu_legacy_files[] = {
#ifdef CONFIG_FAIR_GROUP_SCHED
{
.name = "shares",
@@ -8543,7 +8543,7 @@ static struct cftype cpu_files[] = {
},
{
.name = "stat",
- .seq_show = cpu_stats_show,
+ .seq_show = cpu_cfs_stats_show,
},
#endif
#ifdef CONFIG_RT_GROUP_SCHED
@@ -8568,7 +8568,7 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.fork = cpu_cgroup_fork,
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
- .legacy_cftypes = cpu_files,
+ .legacy_cftypes = cpu_legacy_files,
.early_init = true,
};
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 41f85c4..3eb9eda 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -242,36 +242,33 @@ static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
return __cpuacct_percpu_seq_show(m, CPUACCT_USAGE_NRUSAGE);
}
-static const char * const cpuacct_stat_desc[] = {
- [CPUACCT_STAT_USER] = "user",
- [CPUACCT_STAT_SYSTEM] = "system",
-};
-
-static int cpuacct_stats_show(struct seq_file *sf, void *v)
+static void cpuacct_stats_read(struct cpuacct *ca, u64 *userp, u64 *sysp)
{
- struct cpuacct *ca = css_ca(seq_css(sf));
int cpu;
- s64 val = 0;
+ *userp = 0;
for_each_possible_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_USER];
- val += kcpustat->cpustat[CPUTIME_NICE];
+ *userp += kcpustat->cpustat[CPUTIME_USER];
+ *userp += kcpustat->cpustat[CPUTIME_NICE];
}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
- val = 0;
+ *sysp = 0;
for_each_possible_cpu(cpu) {
struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
- val += kcpustat->cpustat[CPUTIME_SYSTEM];
- val += kcpustat->cpustat[CPUTIME_IRQ];
- val += kcpustat->cpustat[CPUTIME_SOFTIRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SYSTEM];
+ *sysp += kcpustat->cpustat[CPUTIME_IRQ];
+ *sysp += kcpustat->cpustat[CPUTIME_SOFTIRQ];
}
+}
- val = cputime64_to_clock_t(val);
- seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
+{
+ cputime64_t user, sys;
+ cpuacct_stats_read(css_ca(seq_css(sf)), &user, &sys);
+ seq_printf(sf, "user %lld\n", cputime64_to_clock_t(user));
+ seq_printf(sf, "system %lld\n", cputime64_to_clock_t(sys));
return 0;
}
commit ed6d93036ec930cb774da10b7c87f67905ce71f1
Author: Tejun Heo <tj@kernel.org>
Date: Fri Mar 11 07:31:23 2016 -0500
sched: Implement interface for cgroup unified hierarchy
While the cpu controller doesn't have any functional problems, there
are a couple interface issues which can be addressed in the v2
interface.
* cpuacct being a separate controller. This separation is artificial
and rather pointless as demonstrated by most use cases co-mounting
the two controllers. It also forces certain information to be
accounted twice.
* Use of different time units. Writable control knobs use
microseconds, some stat fields use nanoseconds while other cpuacct
stat fields use centiseconds.
* Control knobs which can't be used in the root cgroup still show up
in the root.
* Control knob names and semantics aren't consistent with other
controllers.
This patchset implements cpu controller's interface on the unified
hierarchy which adheres to the controller file conventions described
in Documentation/cgroups/unified-hierarchy.txt. Overall, the
following changes are made.
* cpuacct is implictly enabled and disabled by cpu and its information
is reported through "cpu.stat" which now uses microseconds for all
time durations. All time duration fields now have "_usec" appended
to them for clarity. While this doesn't solve the double accounting
immediately, once majority of users switch to v2, cpu can directly
account and report the relevant stats and cpuacct can be disabled on
the unified hierarchy.
Note that cpuacct.usage_percpu is currently not included in
"cpu.stat". If this information is actually called for, it can be
added later.
* "cpu.shares" is replaced with "cpu.weight" and operates on the
standard scale defined by CGROUP_WEIGHT_MIN/DFL/MAX (1, 100, 10000).
The weight is scaled to scheduler weight so that 100 maps to 1024
and the ratio relationship is preserved - if weight is W and its
scaled value is S, W / 100 == S / 1024. While the mapped range is a
bit smaller than the orignal scheduler weight range, the dead zones
on both sides are relatively small and covers wider range than the
nice value mappings. This file doesn't make sense in the root
cgroup and isn't create on root.
* "cpu.cfs_quota_us" and "cpu.cfs_period_us" are replaced by "cpu.max"
which contains both quota and period.
* "cpu.rt_runtime_us" and "cpu.rt_period_us" are replaced by
"cpu.rt.max" which contains both runtime and period.
v2: cpu_stats_show() was incorrectly using CONFIG_FAIR_GROUP_SCHED for
CFS bandwidth stats and also using raw division for u64. Use
CONFIG_CFS_BANDWITH and do_div() instead.
The semantics of "cpu.rt.max" is not fully decided yet. Dropped
for now.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c148dfe..7bba2c5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -8561,6 +8561,139 @@ static struct cftype cpu_legacy_files[] = {
{ } /* terminate */
};
+static int cpu_stats_show(struct seq_file *sf, void *v)
+{
+ cpuacct_cpu_stats_show(sf);
+
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ struct task_group *tg = css_tg(seq_css(sf));
+ struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
+ u64 throttled_usec;
+
+ throttled_usec = cfs_b->throttled_time;
+ do_div(throttled_usec, NSEC_PER_USEC);
+
+ seq_printf(sf, "nr_periods %d\n"
+ "nr_throttled %d\n"
+ "throttled_usec %llu\n",
+ cfs_b->nr_periods, cfs_b->nr_throttled,
+ throttled_usec);
+ }
+#endif
+ return 0;
+}
+
+#ifdef CONFIG_FAIR_GROUP_SCHED
+static u64 cpu_weight_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ struct task_group *tg = css_tg(css);
+ u64 weight = scale_load_down(tg->shares);
+
+ return DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024);
+}
+
+static int cpu_weight_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 weight)
+{
+ /*
+ * cgroup weight knobs should use the common MIN, DFL and MAX
+ * values which are 1, 100 and 10000 respectively. While it loses
+ * a bit of range on both ends, it maps pretty well onto the shares
+ * value used by scheduler and the round-trip conversions preserve
+ * the original value over the entire range.
+ */
+ if (weight < CGROUP_WEIGHT_MIN || weight > CGROUP_WEIGHT_MAX)
+ return -ERANGE;
+
+ weight = DIV_ROUND_CLOSEST_ULL(weight * 1024, CGROUP_WEIGHT_DFL);
+
+ return sched_group_set_shares(css_tg(css), scale_load(weight));
+}
+#endif
+
+static void __maybe_unused cpu_period_quota_print(struct seq_file *sf,
+ long period, long quota)
+{
+ if (quota < 0)
+ seq_puts(sf, "max");
+ else
+ seq_printf(sf, "%ld", quota);
+
+ seq_printf(sf, " %ld\n", period);
+}
+
+/* caller should put the current value in *@periodp before calling */
+static int __maybe_unused cpu_period_quota_parse(char *buf,
+ u64 *periodp, u64 *quotap)
+{
+ char tok[21]; /* U64_MAX */
+
+ if (!sscanf(buf, "%s %llu", tok, periodp))
+ return -EINVAL;
+
+ *periodp *= NSEC_PER_USEC;
+
+ if (sscanf(tok, "%llu", quotap))
+ *quotap *= NSEC_PER_USEC;
+ else if (!strcmp(tok, "max"))
+ *quotap = RUNTIME_INF;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+
+#ifdef CONFIG_CFS_BANDWIDTH
+static int cpu_max_show(struct seq_file *sf, void *v)
+{
+ struct task_group *tg = css_tg(seq_css(sf));
+
+ cpu_period_quota_print(sf, tg_get_cfs_period(tg), tg_get_cfs_quota(tg));
+ return 0;
+}
+
+static ssize_t cpu_max_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
+{
+ struct task_group *tg = css_tg(of_css(of));
+ u64 period = tg_get_cfs_period(tg);
+ u64 quota;
+ int ret;
+
+ ret = cpu_period_quota_parse(buf, &period, &quota);
+ if (!ret)
+ ret = tg_set_cfs_bandwidth(tg, period, quota);
+ return ret ?: nbytes;
+}
+#endif
+
+static struct cftype cpu_files[] = {
+ {
+ .name = "stat",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_stats_show,
+ },
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ {
+ .name = "weight",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_weight_read_u64,
+ .write_u64 = cpu_weight_write_u64,
+ },
+#endif
+#ifdef CONFIG_CFS_BANDWIDTH
+ {
+ .name = "max",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .seq_show = cpu_max_show,
+ .write = cpu_max_write,
+ },
+#endif
+ { } /* terminate */
+};
+
struct cgroup_subsys cpu_cgrp_subsys = {
.css_alloc = cpu_cgroup_css_alloc,
.css_released = cpu_cgroup_css_released,
@@ -8569,7 +8702,15 @@ struct cgroup_subsys cpu_cgrp_subsys = {
.can_attach = cpu_cgroup_can_attach,
.attach = cpu_cgroup_attach,
.legacy_cftypes = cpu_legacy_files,
+ .dfl_cftypes = cpu_files,
.early_init = true,
+#ifdef CONFIG_CGROUP_CPUACCT
+ /*
+ * cpuacct is enabled together with cpu on the unified hierarchy
+ * and its stats are reported through "cpu.stat".
+ */
+ .depends_on = 1 << cpuacct_cgrp_id,
+#endif
};
#endif /* CONFIG_CGROUP_SCHED */
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 3eb9eda..7a02d26 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -305,6 +305,30 @@ static struct cftype files[] = {
{ } /* terminate */
};
+/* used to print cpuacct stats in cpu.stat on the unified hierarchy */
+void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+ struct cgroup_subsys_state *css;
+ u64 usage, user, sys;
+
+ css = cgroup_get_e_css(seq_css(sf)->cgroup, &cpuacct_cgrp_subsys);
+
+ usage = cpuusage_read(css, seq_cft(sf));
+ cpuacct_stats_read(css_ca(css), &user, &sys);
+
+ user *= TICK_NSEC;
+ sys *= TICK_NSEC;
+ do_div(usage, NSEC_PER_USEC);
+ do_div(user, NSEC_PER_USEC);
+ do_div(sys, NSEC_PER_USEC);
+
+ seq_printf(sf, "usage_usec %llu\n"
+ "user_usec %llu\n"
+ "system_usec %llu\n", usage, user, sys);
+
+ css_put(css);
+}
+
/*
* charge this task's execution time to its accounting group.
*
diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h
index ba72807..ddf7af4 100644
--- a/kernel/sched/cpuacct.h
+++ b/kernel/sched/cpuacct.h
@@ -2,6 +2,7 @@
extern void cpuacct_charge(struct task_struct *tsk, u64 cputime);
extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val);
+extern void cpuacct_cpu_stats_show(struct seq_file *sf);
#else
@@ -14,4 +15,8 @@ cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
{
}
+static inline void cpuacct_cpu_stats_show(struct seq_file *sf)
+{
+}
+
#endif

View File

@ -0,0 +1,21 @@
Patches for CPU Controller on Control Group v2
===============================================
See Tejun Heo's [explanation][1] for why these patches are currently
out-of-tree.
Generating the patches
-----------------------
In a linux checkout, with remote tc-cgroup pointing to
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git, your
nixpkgs checkout in the same directory as your linux checkout (or
modify the command accordingly), and setting `ver` to the appropriate
version:
```shell
$ ver=4.7
$ git log --reverse --patch v$ver..remotes/tc-cgroup/cgroup-v2-cpu-v$ver > ../nixpkgs/pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/$ver.patch
```
[1]: https://git.kernel.org/cgit/linux/kernel/git/tj/cgroup.git/tree/Documentation/cgroup-v2-cpu.txt?h=cgroup-v2-cpu

View File

@ -0,0 +1,11 @@
let
ents = builtins.readDir ./.;
in builtins.listToAttrs (builtins.filter (x: x != null) (map (name: let
match = builtins.match "(.*)\\.patch" name;
in if match == null then null else {
name = builtins.head match;
value = {
name = "cpu-cgroup-v2-${name}";
patch = ./. + "/${name}";
};
}) (builtins.attrNames ents)))

View File

@ -144,4 +144,6 @@ rec {
sha256 = "14rm1qr87p7a5prz8g5fwbpxzdp3ighj095x8rvhm8csm20wspyy";
};
};
cpu-cgroup-v2 = import ./cpu-cgroup-v2-patches;
}

View File

@ -11165,6 +11165,7 @@ in
linux_4_4 = callPackage ../os-specific/linux/kernel/linux-4.4.nix {
kernelPatches =
[ kernelPatches.bridge_stp_helper
kernelPatches.cpu-cgroup-v2."4.4"
]
++ lib.optionals ((platform.kernelArch or null) == "mips")
[ kernelPatches.mips_fpureg_emu
@ -11176,6 +11177,7 @@ in
linux_4_6 = callPackage ../os-specific/linux/kernel/linux-4.6.nix {
kernelPatches =
[ kernelPatches.bridge_stp_helper
kernelPatches.cpu-cgroup-v2."4.6"
]
++ lib.optionals ((platform.kernelArch or null) == "mips")
[ kernelPatches.mips_fpureg_emu
@ -11187,6 +11189,9 @@ in
linux_4_7 = callPackage ../os-specific/linux/kernel/linux-4.7.nix {
kernelPatches =
[ kernelPatches.bridge_stp_helper
# See pkgs/os-specific/linux/kernel/cpu-cgroup-v2-patches/README.md
# when adding a new linux version
kernelPatches.cpu-cgroup-v2."4.7"
]
++ lib.optionals ((platform.kernelArch or null) == "mips")
[ kernelPatches.mips_fpureg_emu