From: Ira Weiny <ira.weiny@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Fenghua Yu <fenghua.yu@intel.com>,
linux-doc@vger.kernel.org, linux-nvdimm@lists.01.org,
linux-mm@kvack.org, linux-kselftest@vger.kernel.org,
Dan Williams <dan.j.williams@intel.com>,
Greg KH <gregkh@linuxfoundation.org>
Subject: Re: [PATCH V3 05/10] x86/entry: Pass irqentry_state_t by reference
Date: Mon, 16 Nov 2020 10:49:16 -0800 [thread overview]
Message-ID: <20201116184916.GA722447@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <87mtzi8n0z.fsf@nanos.tec.linutronix.de>
On Sun, Nov 15, 2020 at 07:58:52PM +0100, Thomas Gleixner wrote:
> Ira,
>
> On Fri, Nov 06 2020 at 15:29, ira weiny wrote:
>
> Subject prefix wants to 'entry:'. This changes generic code and the x86
> part is just required to fix the generic code change.
Sorry, yes that was carried incorrectly from earlier versions.
>
> > Currently struct irqentry_state_t only contains a single bool value
> > which makes passing it by value is reasonable. However, future patches
> > propose to add information to this struct, for example the PKRS
> > register/thread state.
> >
> > Adding information to irqentry_state_t makes passing by value less
> > efficient. Therefore, change the entry/exit calls to pass irq_state by
> > reference.
>
> The PKRS muck needs to add an u32 to that struct. So how is that a
> problem?
There are more fields to be added for the kmap/pmem support. So this will be
needed eventually. Even though it is not strictly necessary in the next patch.
>
> The resulting struct still fits into 64bit which is by far more
> efficiently passed by value than by reference. So which problem are you
> solving here?
I'm getting ahead of myself a bit. I will be adding more fields for the
kmap/pmem tracking.
Would you accept just a clean up for the variable names in this patch? I could
then add the pass by reference when I add the new fields later. Or would an
update to the commit message be ok to land this now?
Ira
>
> Thanks
>
> tglx
>
next prev parent reply other threads:[~2020-11-16 18:49 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-06 23:28 [PATCH V3 00/10] PKS: Add Protection Keys Supervisor (PKS) support V3 ira.weiny
2020-11-06 23:28 ` [PATCH V3 01/10] x86/pkeys: Create pkeys_common.h ira.weiny
2020-11-06 23:29 ` [PATCH V3 02/10] x86/fpu: Refactor arch_set_user_pkey_access() for PKS support ira.weiny
2020-11-06 23:29 ` [PATCH V3 03/10] x86/pks: Add PKS defines and Kconfig options ira.weiny
2020-11-06 23:29 ` [PATCH V3 04/10] x86/pks: Preserve the PKRS MSR on context switch ira.weiny
2020-12-17 14:50 ` Thomas Gleixner
2020-12-17 22:43 ` Thomas Gleixner
2020-12-18 13:57 ` Thomas Gleixner
2020-12-18 19:20 ` Dan Williams
2020-12-18 21:06 ` Thomas Gleixner
2020-12-18 21:58 ` Dan Williams
2020-12-18 22:44 ` Thomas Gleixner
2020-12-18 19:42 ` Ira Weiny
2020-12-18 20:10 ` Dave Hansen
2020-12-18 21:30 ` Thomas Gleixner
2020-12-18 4:05 ` Ira Weiny
2020-12-17 20:41 ` [NEEDS-REVIEW] " Dave Hansen
2020-12-18 4:10 ` Ira Weiny
2020-12-18 15:33 ` Dave Hansen
2020-11-06 23:29 ` [PATCH V3 05/10] x86/entry: Pass irqentry_state_t by reference ira.weiny
2020-11-15 18:58 ` Thomas Gleixner
2020-11-16 18:49 ` Ira Weiny [this message]
2020-11-16 20:36 ` Thomas Gleixner
2020-11-24 6:09 ` [PATCH V3.1] entry: " ira.weiny
2020-12-11 22:14 ` Andy Lutomirski
2020-12-16 1:32 ` Ira Weiny
2020-12-16 2:09 ` Andy Lutomirski
2020-12-17 0:38 ` Ira Weiny
2020-12-17 13:07 ` Thomas Gleixner
2020-12-17 13:19 ` Peter Zijlstra
2020-12-17 15:35 ` Andy Lutomirski
2020-12-17 16:58 ` Thomas Gleixner
2020-11-06 23:29 ` [PATCH V3 06/10] x86/entry: Preserve PKRS MSR across exceptions ira.weiny
2020-12-17 15:28 ` Thomas Gleixner
2020-11-06 23:29 ` [PATCH V3 07/10] x86/fault: Report the PKRS state on fault ira.weiny
2020-11-06 23:29 ` [PATCH V3 08/10] x86/pks: Add PKS kernel API ira.weiny
2020-12-23 20:39 ` Randy Dunlap
2020-11-06 23:29 ` [PATCH V3 09/10] x86/pks: Enable Protection Keys Supervisor (PKS) ira.weiny
2020-11-06 23:29 ` [PATCH V3 10/10] x86/pks: Add PKS test code ira.weiny
2020-12-17 20:55 ` Dave Hansen
2020-12-18 4:05 ` Ira Weiny
2020-12-18 16:59 ` Dan Williams
2020-12-07 22:14 ` [PATCH V3 00/10] PKS: Add Protection Keys Supervisor (PKS) support V3 Ira Weiny
2020-12-08 15:55 ` Thomas Gleixner
2020-12-08 17:22 ` Ira Weiny
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