Re: [PATCH rcu 05/12] srcu: Standardize srcu_data pointers to "sdp" and similar
On 10/15/2024 5:59 AM, Paul E. McKenney wrote: > On Mon, Oct 14, 2024 at 09:49:52AM -0700, Paul E. McKenney wrote: >> On Mon, Oct 14, 2024 at 02:45:50PM +0530, Neeraj Upadhyay wrote: >>> On 10/9/2024 11:37 PM, Paul E. McKenney wrote: This commit changes a few "cpuc" variables to "sdp" to align wiht usage elsewhere. >>> >>> s/wiht/with/ >> >> Good eyes! > > And fixed. > >>> This commit is doing a lot more than renaming "cpuc". >> >> Indeed, it does look like I forgot to commit between two changes. >> >> It looks like this commit log goes with the changes to the >> functions srcu_readers_lock_idx(), srcu_readers_unlock_idx(), and >> srcu_readers_active(). With the exception of the change from "NMI-safe" >> to "reader flavors in the WARN_ONCE() string in srcu_readers_unlock_idx(). >> >> How would you suggest that I split up the non-s/cpuc/sdp/ changes? > > As a first step, I split it three ways, as you can see on the updated "dev" > branch in the -rcu tree. > > Thoughts? > Split looks good to me! - Neeraj > Thanx, Paul > >>> - Neeraj >>> Signed-off-by: Paul E. McKenney Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Peter Zijlstra Cc: Kent Overstreet Cc: --- include/linux/srcu.h | 35 ++ include/linux/srcutree.h | 4 kernel/rcu/srcutree.c| 41 3 files changed, 44 insertions(+), 36 deletions(-) diff --git a/include/linux/srcu.h b/include/linux/srcu.h index 06728ef6f32a4..84daaa33ea0ab 100644 --- a/include/linux/srcu.h +++ b/include/linux/srcu.h @@ -176,10 +176,6 @@ static inline int srcu_read_lock_held(const struct srcu_struct *ssp) #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ -#define SRCU_NMI_UNKNOWN 0x0 -#define SRCU_NMI_UNSAFE 0x1 -#define SRCU_NMI_SAFE 0x2 - #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU) void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor); #else @@ -235,16 +231,19 @@ static inline void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flav * a mutex that is held elsewhere while calling synchronize_srcu() or * synchronize_srcu_expedited(). * - * Note that srcu_read_lock() and the matching srcu_read_unlock() must - * occur in the same context, for example, it is illegal to invoke - * srcu_read_unlock() in an irq handler if the matching srcu_read_lock() - * was invoked in process context. + * The return value from srcu_read_lock() must be passed unaltered + * to the matching srcu_read_unlock(). Note that srcu_read_lock() and + * the matching srcu_read_unlock() must occur in the same context, for + * example, it is illegal to invoke srcu_read_unlock() in an irq handler + * if the matching srcu_read_lock() was invoked in process context. Or, + * for that matter to invoke srcu_read_unlock() from one task and the + * matching srcu_read_lock() from another. */ static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp) { int retval; - srcu_check_read_flavor(ssp, false); + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); retval = __srcu_read_lock(ssp); srcu_lock_acquire(&ssp->dep_map); return retval; @@ -256,12 +255,16 @@ static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp) * * Enter an SRCU read-side critical section, but in an NMI-safe manner. * See srcu_read_lock() for more information. + * + * If srcu_read_lock_nmisafe() is ever used on an srcu_struct structure, + * then none of the other flavors may be used, whether before, during, + * or after. */ static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) __acquires(ssp) { int retval; - srcu_check_read_flavor(ssp, true); + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI); retval = __srcu_read_lock_nmisafe(ssp); rcu_try_lock_acquire(&ssp->dep_map); return retval; @@ -273,7 +276,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp) { int retval; - srcu_check_read_flavor(ssp, false); + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); retval = __srcu_read_lock(ssp); return retval; } @@ -302,7 +305,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) __acquires(ssp) static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp) { WARN_ON_ONCE(in_nmi()); - srcu_check_read_flavor(ssp, false); + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); return __srcu_read_lock(ssp); } >
Re: [PATCH rcu 05/12] srcu: Standardize srcu_data pointers to "sdp" and similar
On Mon, Oct 14, 2024 at 09:49:52AM -0700, Paul E. McKenney wrote: > On Mon, Oct 14, 2024 at 02:45:50PM +0530, Neeraj Upadhyay wrote: > > On 10/9/2024 11:37 PM, Paul E. McKenney wrote: > > > This commit changes a few "cpuc" variables to "sdp" to align wiht usage > > > elsewhere. > > > > > > > s/wiht/with/ > > Good eyes! And fixed. > > This commit is doing a lot more than renaming "cpuc". > > Indeed, it does look like I forgot to commit between two changes. > > It looks like this commit log goes with the changes to the > functions srcu_readers_lock_idx(), srcu_readers_unlock_idx(), and > srcu_readers_active(). With the exception of the change from "NMI-safe" > to "reader flavors in the WARN_ONCE() string in srcu_readers_unlock_idx(). > > How would you suggest that I split up the non-s/cpuc/sdp/ changes? As a first step, I split it three ways, as you can see on the updated "dev" branch in the -rcu tree. Thoughts? Thanx, Paul > > - Neeraj > > > > > Signed-off-by: Paul E. McKenney > > > Cc: Alexei Starovoitov > > > Cc: Andrii Nakryiko > > > Cc: Peter Zijlstra > > > Cc: Kent Overstreet > > > Cc: > > > --- > > > include/linux/srcu.h | 35 ++ > > > include/linux/srcutree.h | 4 > > > kernel/rcu/srcutree.c| 41 > > > 3 files changed, 44 insertions(+), 36 deletions(-) > > > > > > diff --git a/include/linux/srcu.h b/include/linux/srcu.h > > > index 06728ef6f32a4..84daaa33ea0ab 100644 > > > --- a/include/linux/srcu.h > > > +++ b/include/linux/srcu.h > > > @@ -176,10 +176,6 @@ static inline int srcu_read_lock_held(const struct > > > srcu_struct *ssp) > > > > > > #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > > > > > -#define SRCU_NMI_UNKNOWN 0x0 > > > -#define SRCU_NMI_UNSAFE 0x1 > > > -#define SRCU_NMI_SAFE0x2 > > > - > > > #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU) > > > void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor); > > > #else > > > @@ -235,16 +231,19 @@ static inline void srcu_check_read_flavor(struct > > > srcu_struct *ssp, int read_flav > > > * a mutex that is held elsewhere while calling synchronize_srcu() or > > > * synchronize_srcu_expedited(). > > > * > > > - * Note that srcu_read_lock() and the matching srcu_read_unlock() must > > > - * occur in the same context, for example, it is illegal to invoke > > > - * srcu_read_unlock() in an irq handler if the matching srcu_read_lock() > > > - * was invoked in process context. > > > + * The return value from srcu_read_lock() must be passed unaltered > > > + * to the matching srcu_read_unlock(). Note that srcu_read_lock() and > > > + * the matching srcu_read_unlock() must occur in the same context, for > > > + * example, it is illegal to invoke srcu_read_unlock() in an irq handler > > > + * if the matching srcu_read_lock() was invoked in process context. Or, > > > + * for that matter to invoke srcu_read_unlock() from one task and the > > > + * matching srcu_read_lock() from another. > > > */ > > > static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp) > > > { > > > int retval; > > > > > > - srcu_check_read_flavor(ssp, false); > > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > > retval = __srcu_read_lock(ssp); > > > srcu_lock_acquire(&ssp->dep_map); > > > return retval; > > > @@ -256,12 +255,16 @@ static inline int srcu_read_lock(struct srcu_struct > > > *ssp) __acquires(ssp) > > > * > > > * Enter an SRCU read-side critical section, but in an NMI-safe manner. > > > * See srcu_read_lock() for more information. > > > + * > > > + * If srcu_read_lock_nmisafe() is ever used on an srcu_struct structure, > > > + * then none of the other flavors may be used, whether before, during, > > > + * or after. > > > */ > > > static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) > > > __acquires(ssp) > > > { > > > int retval; > > > > > > - srcu_check_read_flavor(ssp, true); > > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI); > > > retval = __srcu_read_lock_nmisafe(ssp); > > > rcu_try_lock_acquire(&ssp->dep_map); > > > return retval; > > > @@ -273,7 +276,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > > > __acquires(ssp) > > > { > > > int retval; > > > > > > - srcu_check_read_flavor(ssp, false); > > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > > retval = __srcu_read_lock(ssp); > > > return retval; > > > } > > > @@ -302,7 +305,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > > > __acquires(ssp) > > > static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp) > > > { > > > WARN_ON_ONCE(in_nmi()); > > > - srcu_check_read_flavor(ssp, false); > > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > > return __srcu_read_lock(ssp); > > > } > > > > > > @@ -317,7 +320,7 @@ static inline
Re: [PATCH rcu 05/12] srcu: Standardize srcu_data pointers to "sdp" and similar
On Mon, Oct 14, 2024 at 02:45:50PM +0530, Neeraj Upadhyay wrote: > On 10/9/2024 11:37 PM, Paul E. McKenney wrote: > > This commit changes a few "cpuc" variables to "sdp" to align wiht usage > > elsewhere. > > > > s/wiht/with/ Good eyes! > This commit is doing a lot more than renaming "cpuc". Indeed, it does look like I forgot to commit between two changes. It looks like this commit log goes with the changes to the functions srcu_readers_lock_idx(), srcu_readers_unlock_idx(), and srcu_readers_active(). With the exception of the change from "NMI-safe" to "reader flavors in the WARN_ONCE() string in srcu_readers_unlock_idx(). How would you suggest that I split up the non-s/cpuc/sdp/ changes? Thanx, Paul > - Neeraj > > > Signed-off-by: Paul E. McKenney > > Cc: Alexei Starovoitov > > Cc: Andrii Nakryiko > > Cc: Peter Zijlstra > > Cc: Kent Overstreet > > Cc: > > --- > > include/linux/srcu.h | 35 ++ > > include/linux/srcutree.h | 4 > > kernel/rcu/srcutree.c| 41 > > 3 files changed, 44 insertions(+), 36 deletions(-) > > > > diff --git a/include/linux/srcu.h b/include/linux/srcu.h > > index 06728ef6f32a4..84daaa33ea0ab 100644 > > --- a/include/linux/srcu.h > > +++ b/include/linux/srcu.h > > @@ -176,10 +176,6 @@ static inline int srcu_read_lock_held(const struct > > srcu_struct *ssp) > > > > #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > > > -#define SRCU_NMI_UNKNOWN 0x0 > > -#define SRCU_NMI_UNSAFE0x1 > > -#define SRCU_NMI_SAFE 0x2 > > - > > #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU) > > void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor); > > #else > > @@ -235,16 +231,19 @@ static inline void srcu_check_read_flavor(struct > > srcu_struct *ssp, int read_flav > > * a mutex that is held elsewhere while calling synchronize_srcu() or > > * synchronize_srcu_expedited(). > > * > > - * Note that srcu_read_lock() and the matching srcu_read_unlock() must > > - * occur in the same context, for example, it is illegal to invoke > > - * srcu_read_unlock() in an irq handler if the matching srcu_read_lock() > > - * was invoked in process context. > > + * The return value from srcu_read_lock() must be passed unaltered > > + * to the matching srcu_read_unlock(). Note that srcu_read_lock() and > > + * the matching srcu_read_unlock() must occur in the same context, for > > + * example, it is illegal to invoke srcu_read_unlock() in an irq handler > > + * if the matching srcu_read_lock() was invoked in process context. Or, > > + * for that matter to invoke srcu_read_unlock() from one task and the > > + * matching srcu_read_lock() from another. > > */ > > static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp) > > { > > int retval; > > > > - srcu_check_read_flavor(ssp, false); > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > retval = __srcu_read_lock(ssp); > > srcu_lock_acquire(&ssp->dep_map); > > return retval; > > @@ -256,12 +255,16 @@ static inline int srcu_read_lock(struct srcu_struct > > *ssp) __acquires(ssp) > > * > > * Enter an SRCU read-side critical section, but in an NMI-safe manner. > > * See srcu_read_lock() for more information. > > + * > > + * If srcu_read_lock_nmisafe() is ever used on an srcu_struct structure, > > + * then none of the other flavors may be used, whether before, during, > > + * or after. > > */ > > static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) > > __acquires(ssp) > > { > > int retval; > > > > - srcu_check_read_flavor(ssp, true); > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI); > > retval = __srcu_read_lock_nmisafe(ssp); > > rcu_try_lock_acquire(&ssp->dep_map); > > return retval; > > @@ -273,7 +276,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > > __acquires(ssp) > > { > > int retval; > > > > - srcu_check_read_flavor(ssp, false); > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > retval = __srcu_read_lock(ssp); > > return retval; > > } > > @@ -302,7 +305,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > > __acquires(ssp) > > static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp) > > { > > WARN_ON_ONCE(in_nmi()); > > - srcu_check_read_flavor(ssp, false); > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > return __srcu_read_lock(ssp); > > } > > > > @@ -317,7 +320,7 @@ static inline void srcu_read_unlock(struct srcu_struct > > *ssp, int idx) > > __releases(ssp) > > { > > WARN_ON_ONCE(idx & ~0x1); > > - srcu_check_read_flavor(ssp, false); > > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > > srcu_lock_release(&ssp->dep_map); > > __srcu_read_unlock(ssp, idx); > > } > > @@ -333,7 +336,7 @@ static inline void srcu_read_unl
Re: [PATCH rcu 05/12] srcu: Standardize srcu_data pointers to "sdp" and similar
On 10/9/2024 11:37 PM, Paul E. McKenney wrote: > This commit changes a few "cpuc" variables to "sdp" to align wiht usage > elsewhere. > s/wiht/with/ This commit is doing a lot more than renaming "cpuc". - Neeraj > Signed-off-by: Paul E. McKenney > Cc: Alexei Starovoitov > Cc: Andrii Nakryiko > Cc: Peter Zijlstra > Cc: Kent Overstreet > Cc: > --- > include/linux/srcu.h | 35 ++ > include/linux/srcutree.h | 4 > kernel/rcu/srcutree.c| 41 > 3 files changed, 44 insertions(+), 36 deletions(-) > > diff --git a/include/linux/srcu.h b/include/linux/srcu.h > index 06728ef6f32a4..84daaa33ea0ab 100644 > --- a/include/linux/srcu.h > +++ b/include/linux/srcu.h > @@ -176,10 +176,6 @@ static inline int srcu_read_lock_held(const struct > srcu_struct *ssp) > > #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */ > > -#define SRCU_NMI_UNKNOWN 0x0 > -#define SRCU_NMI_UNSAFE 0x1 > -#define SRCU_NMI_SAFE0x2 > - > #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_TREE_SRCU) > void srcu_check_read_flavor(struct srcu_struct *ssp, int read_flavor); > #else > @@ -235,16 +231,19 @@ static inline void srcu_check_read_flavor(struct > srcu_struct *ssp, int read_flav > * a mutex that is held elsewhere while calling synchronize_srcu() or > * synchronize_srcu_expedited(). > * > - * Note that srcu_read_lock() and the matching srcu_read_unlock() must > - * occur in the same context, for example, it is illegal to invoke > - * srcu_read_unlock() in an irq handler if the matching srcu_read_lock() > - * was invoked in process context. > + * The return value from srcu_read_lock() must be passed unaltered > + * to the matching srcu_read_unlock(). Note that srcu_read_lock() and > + * the matching srcu_read_unlock() must occur in the same context, for > + * example, it is illegal to invoke srcu_read_unlock() in an irq handler > + * if the matching srcu_read_lock() was invoked in process context. Or, > + * for that matter to invoke srcu_read_unlock() from one task and the > + * matching srcu_read_lock() from another. > */ > static inline int srcu_read_lock(struct srcu_struct *ssp) __acquires(ssp) > { > int retval; > > - srcu_check_read_flavor(ssp, false); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > retval = __srcu_read_lock(ssp); > srcu_lock_acquire(&ssp->dep_map); > return retval; > @@ -256,12 +255,16 @@ static inline int srcu_read_lock(struct srcu_struct > *ssp) __acquires(ssp) > * > * Enter an SRCU read-side critical section, but in an NMI-safe manner. > * See srcu_read_lock() for more information. > + * > + * If srcu_read_lock_nmisafe() is ever used on an srcu_struct structure, > + * then none of the other flavors may be used, whether before, during, > + * or after. > */ > static inline int srcu_read_lock_nmisafe(struct srcu_struct *ssp) > __acquires(ssp) > { > int retval; > > - srcu_check_read_flavor(ssp, true); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI); > retval = __srcu_read_lock_nmisafe(ssp); > rcu_try_lock_acquire(&ssp->dep_map); > return retval; > @@ -273,7 +276,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > __acquires(ssp) > { > int retval; > > - srcu_check_read_flavor(ssp, false); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > retval = __srcu_read_lock(ssp); > return retval; > } > @@ -302,7 +305,7 @@ srcu_read_lock_notrace(struct srcu_struct *ssp) > __acquires(ssp) > static inline int srcu_down_read(struct srcu_struct *ssp) __acquires(ssp) > { > WARN_ON_ONCE(in_nmi()); > - srcu_check_read_flavor(ssp, false); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > return __srcu_read_lock(ssp); > } > > @@ -317,7 +320,7 @@ static inline void srcu_read_unlock(struct srcu_struct > *ssp, int idx) > __releases(ssp) > { > WARN_ON_ONCE(idx & ~0x1); > - srcu_check_read_flavor(ssp, false); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > srcu_lock_release(&ssp->dep_map); > __srcu_read_unlock(ssp, idx); > } > @@ -333,7 +336,7 @@ static inline void srcu_read_unlock_nmisafe(struct > srcu_struct *ssp, int idx) > __releases(ssp) > { > WARN_ON_ONCE(idx & ~0x1); > - srcu_check_read_flavor(ssp, true); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NMI); > rcu_lock_release(&ssp->dep_map); > __srcu_read_unlock_nmisafe(ssp, idx); > } > @@ -342,7 +345,7 @@ static inline void srcu_read_unlock_nmisafe(struct > srcu_struct *ssp, int idx) > static inline notrace void > srcu_read_unlock_notrace(struct srcu_struct *ssp, int idx) __releases(ssp) > { > - srcu_check_read_flavor(ssp, false); > + srcu_check_read_flavor(ssp, SRCU_READ_FLAVOR_NORMAL); > __srcu_read_unlock(ssp, idx); > } > > @@ -359,7 +362,7 @@ static inline void srcu_