From: Thomas Gleixner <tglx@linutronix.de> To: Robin Murphy <robin.murphy@arm.com>, Nitesh Lal <nilal@redhat.com>, Jesse Brandeburg <jesse.brandeburg@intel.com>, "frederic\@kernel.org" <frederic@kernel.org>, "juri.lelli\@redhat.com" <juri.lelli@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com> Cc: Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org, intel-wired-lan@lists.osuosl.org, jbrandeb@kernel.org, Alex Belits <abelits@marvell.com>, "linux-api\@vger.kernel.org" <linux-api@vger.kernel.org>, "bhelgaas\@google.com" <bhelgaas@google.com>, "linux-pci\@vger.kernel.org" <linux-pci@vger.kernel.org>, "rostedt\@goodmis.org" <rostedt@goodmis.org>, "peterz\@infradead.org" <peterz@infradead.org>, "davem\@davemloft.net" <davem@davemloft.net>, "akpm\@linux-foundation.org" <akpm@linux-foundation.org>, "sfr\@canb.auug.org.au" <sfr@canb.auug.org.au>, "stephen\@networkplumber.org" <stephen@networkplumber.org>, "rppt\@linux.vnet.ibm.com" <rppt@linux.vnet.ibm.com>, "jinyuqi\@huawei.com" <jinyuqi@huawei.com>, "zhangshaokun\@hisilicon.com" <zhangshaokun@hisilicon.com>, netdev@vger.kernel.org, chris.friesen@windriver.com, Marc Zyngier <maz@kernel.org> Subject: Re: [PATCH tip:irq/core v1] genirq: remove auto-set of the mask when setting the hint Date: Mon, 17 May 2021 21:08:27 +0200 [thread overview] Message-ID: <874kf1faac.ffs@nanos.tec.linutronix.de> (raw) In-Reply-To: <d1d5e797-49ee-4968-88c6-c07119343492@arm.com> On Mon, May 17 2021 at 19:50, Robin Murphy wrote: > On 2021-05-17 19:08, Thomas Gleixner wrote: >> On Mon, May 17 2021 at 18:26, Robin Murphy wrote: >>> On 2021-05-17 17:57, Nitesh Lal wrote: >>> I'm not implying that there isn't a bug, or that this code ever made >>> sense in the first place, just that fixing it will unfortunately be a >>> bit more involved than a simple revert. This patch as-is *will* subtly >>> break at least the system PMU drivers currently using >> >> s/using/abusing/ >> >>> irq_set_affinity_hint() - those I know require the IRQ affinity to >>> follow whichever CPU the PMU context is bound to, in order to meet perf >>> core's assumptions about mutual exclusion. >> >> Which driver is that? > > Right now, any driver which wants to control an IRQ's affinity and also > build as a module, for one thing. I'm familiar with drivers/perf/ where > a basic pattern has been widely copied; Bah. Why the heck can't people talk and just go and rumage until they find something which hopefully does what they want... The name of that function should have rang all alarm bells... > some of the callers in other subsystems appear to *expect* it to set > the underlying affinity as well, but whether any of those added within > the last 6 years represent a functional dependency rather than just a > performance concern I don't know. Sigh. Let me do yet another tree wide audit... Thanks, tglx
WARNING: multiple messages have this Message-ID (diff)
From: Thomas Gleixner <tglx@linutronix.de> To: intel-wired-lan@osuosl.org Subject: [Intel-wired-lan] [PATCH tip:irq/core v1] genirq: remove auto-set of the mask when setting the hint Date: Mon, 17 May 2021 21:08:27 +0200 [thread overview] Message-ID: <874kf1faac.ffs@nanos.tec.linutronix.de> (raw) In-Reply-To: <d1d5e797-49ee-4968-88c6-c07119343492@arm.com> On Mon, May 17 2021 at 19:50, Robin Murphy wrote: > On 2021-05-17 19:08, Thomas Gleixner wrote: >> On Mon, May 17 2021 at 18:26, Robin Murphy wrote: >>> On 2021-05-17 17:57, Nitesh Lal wrote: >>> I'm not implying that there isn't a bug, or that this code ever made >>> sense in the first place, just that fixing it will unfortunately be a >>> bit more involved than a simple revert. This patch as-is *will* subtly >>> break at least the system PMU drivers currently using >> >> s/using/abusing/ >> >>> irq_set_affinity_hint() - those I know require the IRQ affinity to >>> follow whichever CPU the PMU context is bound to, in order to meet perf >>> core's assumptions about mutual exclusion. >> >> Which driver is that? > > Right now, any driver which wants to control an IRQ's affinity and also > build as a module, for one thing. I'm familiar with drivers/perf/ where > a basic pattern has been widely copied; Bah. Why the heck can't people talk and just go and rumage until they find something which hopefully does what they want... The name of that function should have rang all alarm bells... > some of the callers in other subsystems appear to *expect* it to set > the underlying affinity as well, but whether any of those added within > the last 6 years represent a functional dependency rather than just a > performance concern I don't know. Sigh. Let me do yet another tree wide audit... Thanks, tglx
next prev parent reply other threads:[~2021-05-17 19:08 UTC|newest] Thread overview: 71+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-01 2:18 [PATCH tip:irq/core v1] genirq: remove auto-set of the mask when setting the hint Jesse Brandeburg 2021-05-01 2:18 ` [Intel-wired-lan] " Jesse Brandeburg 2021-05-04 12:15 ` Robin Murphy 2021-05-04 12:15 ` [Intel-wired-lan] " Robin Murphy 2021-05-04 14:29 ` Nitesh Lal 2021-05-04 14:29 ` [Intel-wired-lan] " Nitesh Lal 2021-05-04 16:23 ` Jesse Brandeburg 2021-05-04 16:23 ` [Intel-wired-lan] " Jesse Brandeburg 2021-05-17 16:57 ` Nitesh Lal 2021-05-17 16:57 ` [Intel-wired-lan] " Nitesh Lal 2021-05-17 17:26 ` Robin Murphy 2021-05-17 17:26 ` [Intel-wired-lan] " Robin Murphy 2021-05-17 18:08 ` Thomas Gleixner 2021-05-17 18:08 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-17 18:50 ` Robin Murphy 2021-05-17 18:50 ` [Intel-wired-lan] " Robin Murphy 2021-05-17 19:08 ` Thomas Gleixner [this message] 2021-05-17 19:08 ` Thomas Gleixner 2021-05-17 19:43 ` Thomas Gleixner 2021-05-17 19:43 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-17 20:18 ` Thomas Gleixner 2021-05-17 20:18 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-17 18:21 ` Nitesh Lal 2021-05-17 18:21 ` [Intel-wired-lan] " Nitesh Lal 2021-05-17 19:47 ` Thomas Gleixner 2021-05-17 19:47 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-17 21:13 ` Nitesh Lal 2021-05-17 21:13 ` [Intel-wired-lan] " Nitesh Lal 2021-05-17 20:48 ` Thomas Gleixner 2021-05-17 20:48 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-17 22:44 ` Nitesh Lal 2021-05-17 22:44 ` [Intel-wired-lan] " Nitesh Lal 2021-05-18 0:03 ` Thomas Gleixner 2021-05-18 0:03 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-18 0:23 ` Nitesh Lal 2021-05-18 0:23 ` [Intel-wired-lan] " Nitesh Lal 2021-05-20 21:57 ` Nitesh Lal 2021-05-20 21:57 ` [Intel-wired-lan] " Nitesh Lal 2021-05-21 0:03 ` Nitesh Lal 2021-05-21 0:03 ` [Intel-wired-lan] " Nitesh Lal 2021-05-21 11:56 ` Thomas Gleixner 2021-05-21 11:56 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-21 12:03 ` [PATCH] genirq: Provide new interfaces for affinity hints Thomas Gleixner 2021-05-21 12:03 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-21 15:45 ` Lijun Pan 2021-05-21 15:45 ` [Intel-wired-lan] " Lijun Pan 2021-05-21 21:45 ` Thomas Gleixner 2021-05-21 21:45 ` [Intel-wired-lan] " Thomas Gleixner 2021-05-21 16:13 ` Nitesh Lal 2021-05-21 16:13 ` [Intel-wired-lan] " Nitesh Lal 2021-05-21 21:48 ` Thomas Gleixner 2021-05-21 21:48 ` [Intel-wired-lan] " Thomas Gleixner 2021-06-04 20:35 ` Nitesh Lal 2021-06-04 20:35 ` [Intel-wired-lan] " Nitesh Lal 2021-05-27 10:03 ` Shung-Hsi Yu 2021-05-27 10:03 ` [Intel-wired-lan] " Shung-Hsi Yu 2021-05-27 10:21 ` Shung-Hsi Yu 2021-05-27 10:21 ` [Intel-wired-lan] " Shung-Hsi Yu 2021-05-27 13:06 ` Nitesh Lal 2021-05-27 13:06 ` [Intel-wired-lan] " Nitesh Lal 2021-05-28 7:20 ` Shung-Hsi Yu 2021-05-28 7:20 ` [Intel-wired-lan] " Shung-Hsi Yu 2021-06-07 17:00 ` Nitesh Lal 2021-06-07 17:00 ` [Intel-wired-lan] " Nitesh Lal 2021-06-14 16:12 ` Nitesh Lal 2021-06-14 16:12 ` [Intel-wired-lan] " Nitesh Lal 2021-05-21 13:46 ` [PATCH tip:irq/core v1] genirq: remove auto-set of the mask when setting the hint Nitesh Lal 2021-05-21 13:46 ` [Intel-wired-lan] " Nitesh Lal 2021-05-21 15:15 ` Thomas Gleixner 2021-05-21 15:15 ` [Intel-wired-lan] " Thomas Gleixner 2021-12-10 19:54 ` [tip: irq/core] genirq: Provide new interfaces for affinity hints tip-bot2 for Thomas Gleixner
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=874kf1faac.ffs@nanos.tec.linutronix.de \ --to=tglx@linutronix.de \ --cc=abelits@marvell.com \ --cc=akpm@linux-foundation.org \ --cc=bhelgaas@google.com \ --cc=chris.friesen@windriver.com \ --cc=davem@davemloft.net \ --cc=frederic@kernel.org \ --cc=intel-wired-lan@lists.osuosl.org \ --cc=jbrandeb@kernel.org \ --cc=jesse.brandeburg@intel.com \ --cc=jinyuqi@huawei.com \ --cc=juri.lelli@redhat.com \ --cc=linux-api@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pci@vger.kernel.org \ --cc=maz@kernel.org \ --cc=mingo@kernel.org \ --cc=mtosatti@redhat.com \ --cc=netdev@vger.kernel.org \ --cc=nilal@redhat.com \ --cc=peterz@infradead.org \ --cc=robin.murphy@arm.com \ --cc=rostedt@goodmis.org \ --cc=rppt@linux.vnet.ibm.com \ --cc=sfr@canb.auug.org.au \ --cc=stephen@networkplumber.org \ --cc=zhangshaokun@hisilicon.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: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.