Dear RT Folks, I'm pleased to announce the 4.19.106-rt45 stable release. You can get this release via the git tree at: git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git branch: v4.19-rt Head SHA1: d515995ead09469fbddcb2ffff800caab9cb0c5f Or to build 4.19.106-rt45 directly, the following patches should be applied: http://www.kernel.org/pub/linux/kernel/v4.x/linux-4.19.tar.xz http://www.kernel.org/pub/linux/kernel/v4.x/patch-4.19.106.xz http://www.kernel.org/pub/linux/kernel/projects/rt/4.19/patch-4.19.106-rt45.patch.xz You can also build from 4.19.106-rt44 by applying the incremental patch: http://www.kernel.org/pub/linux/kernel/projects/rt/4.19/incr/patch-4.19.106-rt44-rt45.patch.xz Enjoy, -- Steve Changes from v4.19.106-rt44: --- Matt Fleming (1): mm/memcontrol: Move misplaced local_unlock_irqrestore() Scott Wood (2): sched: migrate_enable: Use per-cpu cpu_stop_work sched: migrate_enable: Remove __schedule() call Sebastian Andrzej Siewior (4): userfaultfd: Use a seqlock instead of seqcount locallock: Include header for the `current' macro drm/vmwgfx: Drop preempt_disable() in vmw_fifo_ping_host() tracing: make preempt_lazy and migrate_disable counter smaller Steven Rostedt (VMware) (1): Linux 4.19.106-rt45 ---- drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c | 2 -- fs/userfaultfd.c | 12 ++++++------ include/linux/locallock.h | 1 + include/linux/trace_events.h | 3 +-- kernel/sched/core.c | 23 ++++++++++++++--------- kernel/trace/trace_events.c | 4 ++-- localversion-rt | 2 +- mm/memcontrol.c | 2 +- 8 files changed, 26 insertions(+), 23 deletions(-) --------------------------- diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c index d0fd147ef75f..fb5a3461bb8c 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c @@ -167,10 +167,8 @@ void vmw_fifo_ping_host(struct vmw_private *dev_priv, uint32_t reason) { u32 *fifo_mem = dev_priv->mmio_virt; - preempt_disable(); if (cmpxchg(fifo_mem + SVGA_FIFO_BUSY, 0, 1) == 0) vmw_write(dev_priv, SVGA_REG_SYNC, reason); - preempt_enable(); } void vmw_fifo_release(struct vmw_private *dev_priv, struct vmw_fifo_state *fifo) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d269d1139f7f..ff6be687f68e 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -61,7 +61,7 @@ struct userfaultfd_ctx { /* waitqueue head for events */ wait_queue_head_t event_wqh; /* a refile sequence protected by fault_pending_wqh lock */ - struct seqcount refile_seq; + seqlock_t refile_seq; /* pseudo fd refcounting */ atomic_t refcount; /* userfaultfd syscall flags */ @@ -1064,7 +1064,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, * waitqueue could become empty if this is the * only userfault. */ - write_seqcount_begin(&ctx->refile_seq); + write_seqlock(&ctx->refile_seq); /* * The fault_pending_wqh.lock prevents the uwq @@ -1090,7 +1090,7 @@ static ssize_t userfaultfd_ctx_read(struct userfaultfd_ctx *ctx, int no_wait, list_del(&uwq->wq.entry); add_wait_queue(&ctx->fault_wqh, &uwq->wq); - write_seqcount_end(&ctx->refile_seq); + write_sequnlock(&ctx->refile_seq); /* careful to always initialize msg if ret == 0 */ *msg = uwq->msg; @@ -1263,11 +1263,11 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx, * sure we've userfaults to wake. */ do { - seq = read_seqcount_begin(&ctx->refile_seq); + seq = read_seqbegin(&ctx->refile_seq); need_wakeup = waitqueue_active(&ctx->fault_pending_wqh) || waitqueue_active(&ctx->fault_wqh); cond_resched(); - } while (read_seqcount_retry(&ctx->refile_seq, seq)); + } while (read_seqretry(&ctx->refile_seq, seq)); if (need_wakeup) __wake_userfault(ctx, range); } @@ -1938,7 +1938,7 @@ static void init_once_userfaultfd_ctx(void *mem) init_waitqueue_head(&ctx->fault_wqh); init_waitqueue_head(&ctx->event_wqh); init_waitqueue_head(&ctx->fd_wqh); - seqcount_init(&ctx->refile_seq); + seqlock_init(&ctx->refile_seq); } SYSCALL_DEFINE1(userfaultfd, int, flags) diff --git a/include/linux/locallock.h b/include/linux/locallock.h index 921eab83cd34..81c89d87723b 100644 --- a/include/linux/locallock.h +++ b/include/linux/locallock.h @@ -3,6 +3,7 @@ #include <linux/percpu.h> #include <linux/spinlock.h> +#include <asm/current.h> #ifdef CONFIG_PREEMPT_RT_BASE diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 72864a11cec0..e26a85c1b7ba 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -62,8 +62,7 @@ struct trace_entry { unsigned char flags; unsigned char preempt_count; int pid; - unsigned short migrate_disable; - unsigned short padding; + unsigned char migrate_disable; unsigned char preempt_lazy_count; }; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 4616c086dd26..02e51c74e0bf 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7291,6 +7291,9 @@ static void migrate_disabled_sched(struct task_struct *p) p->migrate_disable_scheduled = 1; } +static DEFINE_PER_CPU(struct cpu_stop_work, migrate_work); +static DEFINE_PER_CPU(struct migration_arg, migrate_arg); + void migrate_enable(void) { struct task_struct *p = current; @@ -7329,23 +7332,25 @@ void migrate_enable(void) WARN_ON(smp_processor_id() != cpu); if (!is_cpu_allowed(p, cpu)) { - struct migration_arg arg = { .task = p }; - struct cpu_stop_work work; + struct migration_arg __percpu *arg; + struct cpu_stop_work __percpu *work; struct rq_flags rf; + work = this_cpu_ptr(&migrate_work); + arg = this_cpu_ptr(&migrate_arg); + WARN_ON_ONCE(!arg->done && !work->disabled && work->arg); + + arg->task = p; + arg->done = false; + rq = task_rq_lock(p, &rf); update_rq_clock(rq); - arg.dest_cpu = select_fallback_rq(cpu, p); + arg->dest_cpu = select_fallback_rq(cpu, p); task_rq_unlock(rq, p, &rf); stop_one_cpu_nowait(task_cpu(p), migration_cpu_stop, - &arg, &work); + arg, work); tlb_migrate_finish(p->mm); - __schedule(true); - if (!work.disabled) { - while (!arg.done) - cpu_relax(); - } } out: diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 1febb0ca4c81..07b8f5bfd263 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -188,8 +188,8 @@ static int trace_define_common_fields(void) __common_field(unsigned char, flags); __common_field(unsigned char, preempt_count); __common_field(int, pid); - __common_field(unsigned short, migrate_disable); - __common_field(unsigned short, padding); + __common_field(unsigned char, migrate_disable); + __common_field(unsigned char, preempt_lazy_count); return ret; } diff --git a/localversion-rt b/localversion-rt index ac4d836a809d..38c40b21a885 100644 --- a/localversion-rt +++ b/localversion-rt @@ -1 +1 @@ --rt44 +-rt45 diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 421ac74450f6..519528959eef 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6540,10 +6540,10 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry) mem_cgroup_charge_statistics(memcg, page, PageTransHuge(page), -nr_entries); memcg_check_events(memcg, page); + local_unlock_irqrestore(event_lock, flags); if (!mem_cgroup_is_root(memcg)) css_put_many(&memcg->css, nr_entries); - local_unlock_irqrestore(event_lock, flags); } /**
