kernel/sched/psi.c | 2 ++ 1 file changed, 2 insertions(+)
These warnings were reported by checkpatch.
Fix them with minor changes.
No functional changes.
WARNING: memory barrier without comment
+ t = smp_load_acquire(trigger_ptr);
WARNING: memory barrier without comment
+ smp_store_release(&seq->private, new);
Signed-off-by: Pintu Kumar <quic_pintu@quicinc.com>
---
Changes in V5:
Corrected api name and missing () in comments as suggested by Christophe JAILLET.
V4: https://lore.kernel.org/all/a8393bc0-6f56-4e40-b971-4a837cf28323@wanadoo.fr/
Changes in V4:
Added () in comment as well suggested by Christophe JAILLET.
V3: https://lore.kernel.org/all/00aeb243-3d47-42be-b52c-08b39c5fef07@wanadoo.fr/
Changes in V3:
Removed signature of Joe as requested. No other change.
V2: https://lore.kernel.org/all/CAOuPNLi1mUKW_vv0E6Ynzvdw_rHvCye+nAf2bWv6Qj9A8ofX1g@mail.gmail.com/
Changes in V2:
Retain printk_deferred warnings as suggested by Joe Perches.
V1: https://lore.kernel.org/all/a848671f803ba2b4ab14b0f7b09f0f53a8dd1c4b.camel@perches.com/
---
kernel/sched/psi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 020d58967d4e..907fa3830c8e 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -1474,6 +1474,7 @@ __poll_t psi_trigger_poll(void **trigger_ptr,
if (static_branch_likely(&psi_disabled))
return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI;
+ /* Pairs with the smp_store_release() in psi_write() */
t = smp_load_acquire(trigger_ptr);
if (!t)
return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI;
@@ -1557,6 +1558,7 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf,
return PTR_ERR(new);
}
+ /* Pairs with the smp_load_acquire() in psi_trigger_poll() */
smp_store_release(&seq->private, new);
mutex_unlock(&seq->lock);
--
2.17.1
On Sun, Oct 6, 2024 at 1:29 AM Pintu Kumar <quic_pintu@quicinc.com> wrote: > > These warnings were reported by checkpatch. > Fix them with minor changes. > No functional changes. > > WARNING: memory barrier without comment > + t = smp_load_acquire(trigger_ptr); > > WARNING: memory barrier without comment > + smp_store_release(&seq->private, new); > > Signed-off-by: Pintu Kumar <quic_pintu@quicinc.com> Acked-by: Suren Baghdasaryan <surenb@google.com> > > --- > Changes in V5: > Corrected api name and missing () in comments as suggested by Christophe JAILLET. > V4: https://lore.kernel.org/all/a8393bc0-6f56-4e40-b971-4a837cf28323@wanadoo.fr/ > Changes in V4: > Added () in comment as well suggested by Christophe JAILLET. > V3: https://lore.kernel.org/all/00aeb243-3d47-42be-b52c-08b39c5fef07@wanadoo.fr/ > Changes in V3: > Removed signature of Joe as requested. No other change. > V2: https://lore.kernel.org/all/CAOuPNLi1mUKW_vv0E6Ynzvdw_rHvCye+nAf2bWv6Qj9A8ofX1g@mail.gmail.com/ > Changes in V2: > Retain printk_deferred warnings as suggested by Joe Perches. > V1: https://lore.kernel.org/all/a848671f803ba2b4ab14b0f7b09f0f53a8dd1c4b.camel@perches.com/ > --- > kernel/sched/psi.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c > index 020d58967d4e..907fa3830c8e 100644 > --- a/kernel/sched/psi.c > +++ b/kernel/sched/psi.c > @@ -1474,6 +1474,7 @@ __poll_t psi_trigger_poll(void **trigger_ptr, > if (static_branch_likely(&psi_disabled)) > return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI; > > + /* Pairs with the smp_store_release() in psi_write() */ > t = smp_load_acquire(trigger_ptr); > if (!t) > return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI; > @@ -1557,6 +1558,7 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf, > return PTR_ERR(new); > } > > + /* Pairs with the smp_load_acquire() in psi_trigger_poll() */ > smp_store_release(&seq->private, new); > mutex_unlock(&seq->lock); > > -- > 2.17.1 >
Hi, On Tue, 15 Oct 2024 at 02:36, Suren Baghdasaryan <surenb@google.com> wrote: > > On Sun, Oct 6, 2024 at 1:29 AM Pintu Kumar <quic_pintu@quicinc.com> wrote: > > > > These warnings were reported by checkpatch. > > Fix them with minor changes. > > No functional changes. > > > > WARNING: memory barrier without comment > > + t = smp_load_acquire(trigger_ptr); > > > > WARNING: memory barrier without comment > > + smp_store_release(&seq->private, new); > > > > Signed-off-by: Pintu Kumar <quic_pintu@quicinc.com> > > Acked-by: Suren Baghdasaryan <surenb@google.com> > Any further comment on this ?
Hi, On Sun, 6 Oct 2024 at 13:59, Pintu Kumar <quic_pintu@quicinc.com> wrote: > > These warnings were reported by checkpatch. > Fix them with minor changes. > No functional changes. > > WARNING: memory barrier without comment > + t = smp_load_acquire(trigger_ptr); > > WARNING: memory barrier without comment > + smp_store_release(&seq->private, new); > > Signed-off-by: Pintu Kumar <quic_pintu@quicinc.com> > > --- > Changes in V5: > Corrected api name and missing () in comments as suggested by Christophe JAILLET. > V4: https://lore.kernel.org/all/a8393bc0-6f56-4e40-b971-4a837cf28323@wanadoo.fr/ > Changes in V4: > Added () in comment as well suggested by Christophe JAILLET. > V3: https://lore.kernel.org/all/00aeb243-3d47-42be-b52c-08b39c5fef07@wanadoo.fr/ > Changes in V3: > Removed signature of Joe as requested. No other change. > V2: https://lore.kernel.org/all/CAOuPNLi1mUKW_vv0E6Ynzvdw_rHvCye+nAf2bWv6Qj9A8ofX1g@mail.gmail.com/ > Changes in V2: > Retain printk_deferred warnings as suggested by Joe Perches. > V1: https://lore.kernel.org/all/a848671f803ba2b4ab14b0f7b09f0f53a8dd1c4b.camel@perches.com/ > --- > kernel/sched/psi.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c > index 020d58967d4e..907fa3830c8e 100644 > --- a/kernel/sched/psi.c > +++ b/kernel/sched/psi.c > @@ -1474,6 +1474,7 @@ __poll_t psi_trigger_poll(void **trigger_ptr, > if (static_branch_likely(&psi_disabled)) > return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI; > > + /* Pairs with the smp_store_release() in psi_write() */ > t = smp_load_acquire(trigger_ptr); > if (!t) > return DEFAULT_POLLMASK | EPOLLERR | EPOLLPRI; > @@ -1557,6 +1558,7 @@ static ssize_t psi_write(struct file *file, const char __user *user_buf, > return PTR_ERR(new); > } > > + /* Pairs with the smp_load_acquire() in psi_trigger_poll() */ > smp_store_release(&seq->private, new); > mutex_unlock(&seq->lock); > > -- > 2.17.1 > Addressed all review comments on this latest v5. Any further comments on this patchset ? Thanks, Pintu
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