| Message ID | ac615f36-0b44-408d-aeab-d76e4241add4@infradead.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] Documentation/locking/locktypes: minor copy editor fixes | expand |
On Wed, Mar 25, 2020 at 09:58:14AM -0700, Randy Dunlap wrote: > From: Randy Dunlap <rdunlap@infradead.org> > > Minor editorial fixes: > - add some hyphens in multi-word adjectives > - add some periods for consistency > - add "'" for possessive CPU's > - capitalize IRQ when it's an acronym and not part of a function name > > Signed-off-by: Randy Dunlap <rdunlap@infradead.org> > Cc: Paul McKenney <paulmck@kernel.org> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: Sebastian Siewior <bigeasy@linutronix.de> > Cc: Joel Fernandes <joel@joelfernandes.org> > Cc: Ingo Molnar <mingo@kernel.org> > Cc: Peter Zijlstra <peterz@infradead.org> Some nits below, but with or without those suggested changes: Reviewed-by: Paul E. McKenney <paulmck@kernel.org> > --- > Documentation/locking/locktypes.rst | 16 ++++++++-------- > 1 file changed, 8 insertions(+), 8 deletions(-) > > --- linux-next-20200325.orig/Documentation/locking/locktypes.rst > +++ linux-next-20200325/Documentation/locking/locktypes.rst > @@ -84,7 +84,7 @@ rtmutex > > RT-mutexes are mutexes with support for priority inheritance (PI). > > -PI has limitations on non PREEMPT_RT enabled kernels due to preemption and > +PI has limitations on non-PREEMPT_RT-enabled kernels due to preemption and Or just drop the " enabled". > interrupt disabled sections. > > PI clearly cannot preempt preemption-disabled or interrupt-disabled > @@ -150,7 +150,7 @@ kernel configuration including PREEMPT_R > > raw_spinlock_t is a strict spinning lock implementation in all kernels, > including PREEMPT_RT kernels. Use raw_spinlock_t only in real critical > -core code, low level interrupt handling and places where disabling > +core code, low-level interrupt handling and places where disabling > preemption or interrupts is required, for example, to safely access > hardware state. raw_spinlock_t can sometimes also be used when the > critical section is tiny, thus avoiding RT-mutex overhead. > @@ -160,20 +160,20 @@ spinlock_t > > The semantics of spinlock_t change with the state of PREEMPT_RT. > > -On a non PREEMPT_RT enabled kernel spinlock_t is mapped to raw_spinlock_t > +On a non-PREEMPT_RT-enabled kernel spinlock_t is mapped to raw_spinlock_t Ditto. > and has exactly the same semantics. > > spinlock_t and PREEMPT_RT > ------------------------- > > -On a PREEMPT_RT enabled kernel spinlock_t is mapped to a separate > +On a PREEMPT_RT-enabled kernel spinlock_t is mapped to a separate And here as well. > implementation based on rt_mutex which changes the semantics: > > - - Preemption is not disabled > + - Preemption is not disabled. > > - The hard interrupt related suffixes for spin_lock / spin_unlock > - operations (_irq, _irqsave / _irqrestore) do not affect the CPUs > - interrupt disabled state > + operations (_irq, _irqsave / _irqrestore) do not affect the CPU's > + interrupt disabled state. > > - The soft interrupt related suffix (_bh()) still disables softirq > handlers. > @@ -279,7 +279,7 @@ fully preemptible context. Instead, use > spin_lock_irqsave() and their unlock counterparts. In cases where the > interrupt disabling and locking must remain separate, PREEMPT_RT offers a > local_lock mechanism. Acquiring the local_lock pins the task to a CPU, > -allowing things like per-CPU irq-disabled locks to be acquired. However, > +allowing things like per-CPU IRQ-disabled locks to be acquired. However, Quite a bit of text in the kernel uses "irq", lower case. Another option is to spell out "interrupt". > this approach should be used only where absolutely necessary. > > >
--- linux-next-20200325.orig/Documentation/locking/locktypes.rst +++ linux-next-20200325/Documentation/locking/locktypes.rst @@ -84,7 +84,7 @@ rtmutex RT-mutexes are mutexes with support for priority inheritance (PI). -PI has limitations on non PREEMPT_RT enabled kernels due to preemption and +PI has limitations on non-PREEMPT_RT-enabled kernels due to preemption and interrupt disabled sections. PI clearly cannot preempt preemption-disabled or interrupt-disabled @@ -150,7 +150,7 @@ kernel configuration including PREEMPT_R raw_spinlock_t is a strict spinning lock implementation in all kernels, including PREEMPT_RT kernels. Use raw_spinlock_t only in real critical -core code, low level interrupt handling and places where disabling +core code, low-level interrupt handling and places where disabling preemption or interrupts is required, for example, to safely access hardware state. raw_spinlock_t can sometimes also be used when the critical section is tiny, thus avoiding RT-mutex overhead. @@ -160,20 +160,20 @@ spinlock_t The semantics of spinlock_t change with the state of PREEMPT_RT. -On a non PREEMPT_RT enabled kernel spinlock_t is mapped to raw_spinlock_t +On a non-PREEMPT_RT-enabled kernel spinlock_t is mapped to raw_spinlock_t and has exactly the same semantics. spinlock_t and PREEMPT_RT ------------------------- -On a PREEMPT_RT enabled kernel spinlock_t is mapped to a separate +On a PREEMPT_RT-enabled kernel spinlock_t is mapped to a separate implementation based on rt_mutex which changes the semantics: - - Preemption is not disabled + - Preemption is not disabled. - The hard interrupt related suffixes for spin_lock / spin_unlock - operations (_irq, _irqsave / _irqrestore) do not affect the CPUs - interrupt disabled state + operations (_irq, _irqsave / _irqrestore) do not affect the CPU's + interrupt disabled state. - The soft interrupt related suffix (_bh()) still disables softirq handlers. @@ -279,7 +279,7 @@ fully preemptible context. Instead, use spin_lock_irqsave() and their unlock counterparts. In cases where the interrupt disabling and locking must remain separate, PREEMPT_RT offers a local_lock mechanism. Acquiring the local_lock pins the task to a CPU, -allowing things like per-CPU irq-disabled locks to be acquired. However, +allowing things like per-CPU IRQ-disabled locks to be acquired. However, this approach should be used only where absolutely necessary.