From: Nitesh Narayan Lal <nitesh@redhat.com>
To: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org,
linux-api@vger.kernel.org, linux-pci@vger.kernel.org,
tglx@linutronix.de, jesse.brandeburg@intel.com,
robin.murphy@arm.com, mtosatti@redhat.com, mingo@kernel.org,
jbrandeb@kernel.org, frederic@kernel.org, juri.lelli@redhat.com,
abelits@marvell.com, bhelgaas@google.com, rostedt@goodmis.org,
peterz@infradead.org, davem@davemloft.net,
akpm@linux-foundation.org, sfr@canb.auug.org.au,
stephen@networkplumber.org, rppt@linux.vnet.ibm.com,
chris.friesen@windriver.com, maz@kernel.org,
nhorman@tuxdriver.com, pjwaskiewicz@gmail.com,
sassmann@redhat.com, thenzl@redhat.com,
kashyap.desai@broadcom.com, sumit.saxena@broadcom.com,
shivasharan.srikanteshwara@broadcom.com,
sathya.prakash@broadcom.com, sreekanth.reddy@broadcom.com,
suganath-prabu.subramani@broadcom.com, james.smart@broadcom.com,
dick.kennedy@broadcom.com, jkc@redhat.com,
faisal.latif@intel.com, shiraz.saleem@intel.com,
tariqt@nvidia.com, ahleihel@redhat.com, kheib@redhat.com,
borisp@nvidia.com, saeedm@nvidia.com, benve@cisco.com,
govind@gmx.com, jassisinghbrar@gmail.com,
ajit.khaparde@broadcom.com, sriharsha.basavapatna@broadcom.com,
somnath.kotur@broadcom.com, nilal@redhat.com,
tatyana.e.nikolova@intel.com, mustafa.ismail@intel.com,
ahs3@redhat.com, leonro@nvidia.com,
chandrakanth.patil@broadcom.com
Subject: [PATCH v3 01/14] genirq: Provide new interfaces for affinity hints
Date: Tue, 13 Jul 2021 17:14:49 -0400 [thread overview]
Message-ID: <20210713211502.464259-2-nitesh@redhat.com> (raw)
In-Reply-To: <20210713211502.464259-1-nitesh@redhat.com>
From: Thomas Gleixner <tglx@linutronix.de>
The discussion about removing the side effect of irq_set_affinity_hint() of
actually applying the cpumask (if not NULL) as affinity to the interrupt,
unearthed a few unpleasantries:
1) The modular perf drivers rely on the current behaviour for the very
wrong reasons.
2) While none of the other drivers prevents user space from changing
the affinity, a cursorily inspection shows that there are at least
expectations in some drivers.
#1 needs to be cleaned up anyway, so that's not a problem
#2 might result in subtle regressions especially when irqbalanced (which
nowadays ignores the affinity hint) is disabled.
Provide new interfaces:
irq_update_affinity_hint() - Only sets the affinity hint pointer
irq_set_affinity_and_hint() - Set the pointer and apply the affinity to
the interrupt
Make irq_set_affinity_hint() a wrapper around irq_apply_affinity_hint() and
document it to be phased out.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nitesh Narayan Lal <nitesh@redhat.com>
Link: https://lore.kernel.org/r/20210501021832.743094-1-jesse.brandeburg@intel.com
---
include/linux/interrupt.h | 53 ++++++++++++++++++++++++++++++++++++++-
kernel/irq/manage.c | 8 +++---
2 files changed, 56 insertions(+), 5 deletions(-)
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 2ed65b01c961..bd25ba029c68 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -328,7 +328,46 @@ extern int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask);
extern int irq_can_set_affinity(unsigned int irq);
extern int irq_select_affinity(unsigned int irq);
-extern int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m);
+extern int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
+ bool setaffinity);
+
+/**
+ * irq_update_affinity_hint - Update the affinity hint
+ * @irq: Interrupt to update
+ * @cpumask: cpumask pointer (NULL to clear the hint)
+ *
+ * Updates the affinity hint, but does not change the affinity of the interrupt.
+ */
+static inline int
+irq_update_affinity_hint(unsigned int irq, const struct cpumask *m)
+{
+ return __irq_apply_affinity_hint(irq, m, false);
+}
+
+/**
+ * irq_set_affinity_and_hint - Update the affinity hint and apply the provided
+ * cpumask to the interrupt
+ * @irq: Interrupt to update
+ * @cpumask: cpumask pointer (NULL to clear the hint)
+ *
+ * Updates the affinity hint and if @cpumask is not NULL it applies it as
+ * the affinity of that interrupt.
+ */
+static inline int
+irq_set_affinity_and_hint(unsigned int irq, const struct cpumask *m)
+{
+ return __irq_apply_affinity_hint(irq, m, true);
+}
+
+/*
+ * Deprecated. Use irq_update_affinity_hint() or irq_set_affinity_and_hint()
+ * instead.
+ */
+static inline int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+{
+ return irq_set_affinity_and_hint(irq, m);
+}
+
extern int irq_update_affinity_desc(unsigned int irq,
struct irq_affinity_desc *affinity);
@@ -360,6 +399,18 @@ static inline int irq_can_set_affinity(unsigned int irq)
static inline int irq_select_affinity(unsigned int irq) { return 0; }
+static inline int irq_update_affinity_hint(unsigned int irq,
+ const struct cpumask *m)
+{
+ return -EINVAL;
+}
+
+static inline int irq_set_affinity_and_hint(unsigned int irq,
+ const struct cpumask *m)
+{
+ return -EINVAL;
+}
+
static inline int irq_set_affinity_hint(unsigned int irq,
const struct cpumask *m)
{
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index ef30b4762947..837b63e63111 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -487,7 +487,8 @@ int irq_force_affinity(unsigned int irq, const struct cpumask *cpumask)
}
EXPORT_SYMBOL_GPL(irq_force_affinity);
-int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
+int __irq_apply_affinity_hint(unsigned int irq, const struct cpumask *m,
+ bool setaffinity)
{
unsigned long flags;
struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL);
@@ -496,12 +497,11 @@ int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m)
return -EINVAL;
desc->affinity_hint = m;
irq_put_desc_unlock(desc, flags);
- /* set the initial affinity to prevent every interrupt being on CPU0 */
- if (m)
+ if (m && setaffinity)
__irq_set_affinity(irq, m, false);
return 0;
}
-EXPORT_SYMBOL_GPL(irq_set_affinity_hint);
+EXPORT_SYMBOL_GPL(__irq_apply_affinity_hint);
static void irq_affinity_notify(struct work_struct *work)
{
--
2.27.0
next prev parent reply other threads:[~2021-07-13 21:15 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-13 21:14 [PATCH v3 00/14] genirq: Cleanup the usage of irq_set_affinity_hint Nitesh Narayan Lal
2021-07-13 21:14 ` Nitesh Narayan Lal [this message]
2021-07-13 21:14 ` [PATCH v3 02/14] iavf: Use irq_update_affinity_hint Nitesh Narayan Lal
2021-07-13 21:51 ` Jesse Brandeburg
2021-07-13 21:14 ` [PATCH v3 03/14] i40e: " Nitesh Narayan Lal
2021-07-13 21:52 ` Jesse Brandeburg
2021-07-13 21:14 ` [PATCH v3 04/14] scsi: megaraid_sas: Use irq_set_affinity_and_hint Nitesh Narayan Lal
2021-07-13 21:14 ` [PATCH v3 05/14] scsi: mpt3sas: " Nitesh Narayan Lal
2021-07-13 21:14 ` [PATCH v3 06/14] RDMA/irdma: " Nitesh Narayan Lal
2021-07-14 12:03 ` Leon Romanovsky
2021-07-14 12:56 ` Nitesh Lal
2021-07-14 13:02 ` Leon Romanovsky
2021-07-15 13:25 ` Nitesh Lal
2021-07-13 21:14 ` [PATCH v3 07/14] enic: Use irq_update_affinity_hint Nitesh Narayan Lal
2021-07-13 21:14 ` [PATCH v3 08/14] be2net: " Nitesh Narayan Lal
2021-07-13 21:14 ` [PATCH v3 09/14] ixgbe: " Nitesh Narayan Lal
2021-07-13 22:01 ` Jesse Brandeburg
2021-07-13 21:14 ` [PATCH v3 10/14] mailbox: " Nitesh Narayan Lal
2021-07-13 21:14 ` [PATCH v3 11/14] scsi: lpfc: Use irq_set_affinity Nitesh Narayan Lal
2021-07-13 21:15 ` [PATCH v3 12/14] hinic: Use irq_set_affinity_and_hint Nitesh Narayan Lal
2021-07-13 21:15 ` [PATCH v3 13/14] net/mlx5: " Nitesh Narayan Lal
2021-07-14 12:01 ` Leon Romanovsky
2021-07-13 21:15 ` [PATCH v3 14/14] net/mlx4: Use irq_update_affinity_hint Nitesh Narayan Lal
2021-07-14 11:19 ` Tariq Toukan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210713211502.464259-2-nitesh@redhat.com \
--to=nitesh@redhat.com \
--cc=abelits@marvell.com \
--cc=ahleihel@redhat.com \
--cc=ahs3@redhat.com \
--cc=ajit.khaparde@broadcom.com \
--cc=akpm@linux-foundation.org \
--cc=benve@cisco.com \
--cc=bhelgaas@google.com \
--cc=borisp@nvidia.com \
--cc=chandrakanth.patil@broadcom.com \
--cc=chris.friesen@windriver.com \
--cc=davem@davemloft.net \
--cc=dick.kennedy@broadcom.com \
--cc=faisal.latif@intel.com \
--cc=frederic@kernel.org \
--cc=govind@gmx.com \
--cc=intel-wired-lan@lists.osuosl.org \
--cc=james.smart@broadcom.com \
--cc=jassisinghbrar@gmail.com \
--cc=jbrandeb@kernel.org \
--cc=jesse.brandeburg@intel.com \
--cc=jkc@redhat.com \
--cc=juri.lelli@redhat.com \
--cc=kashyap.desai@broadcom.com \
--cc=kheib@redhat.com \
--cc=leonro@nvidia.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-scsi@vger.kernel.org \
--cc=maz@kernel.org \
--cc=mingo@kernel.org \
--cc=mtosatti@redhat.com \
--cc=mustafa.ismail@intel.com \
--cc=netdev@vger.kernel.org \
--cc=nhorman@tuxdriver.com \
--cc=nilal@redhat.com \
--cc=peterz@infradead.org \
--cc=pjwaskiewicz@gmail.com \
--cc=robin.murphy@arm.com \
--cc=rostedt@goodmis.org \
--cc=rppt@linux.vnet.ibm.com \
--cc=saeedm@nvidia.com \
--cc=sassmann@redhat.com \
--cc=sathya.prakash@broadcom.com \
--cc=sfr@canb.auug.org.au \
--cc=shiraz.saleem@intel.com \
--cc=shivasharan.srikanteshwara@broadcom.com \
--cc=somnath.kotur@broadcom.com \
--cc=sreekanth.reddy@broadcom.com \
--cc=sriharsha.basavapatna@broadcom.com \
--cc=stephen@networkplumber.org \
--cc=suganath-prabu.subramani@broadcom.com \
--cc=sumit.saxena@broadcom.com \
--cc=tariqt@nvidia.com \
--cc=tatyana.e.nikolova@intel.com \
--cc=tglx@linutronix.de \
--cc=thenzl@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).