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From: Sohil Mehta <sohil.mehta@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>, <x86@kernel.org>
Cc: Tony Luck <tony.luck@intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	"Ingo Molnar" <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Christian Brauner <christian@brauner.io>,
	Peter Zijlstra <peterz@infradead.org>,
	Shuah Khan <shuah@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
	Jonathan Corbet <corbet@lwn.net>, Ashok Raj <ashok.raj@intel.com>,
	Jacob Pan <jacob.jun.pan@linux.intel.com>,
	"Gayatri Kammela" <gayatri.kammela@intel.com>,
	Zeng Guang <guang.zeng@intel.com>,
	"Dan Williams" <dan.j.williams@intel.com>,
	Randy E Witt <randy.e.witt@intel.com>,
	Ravi V Shankar <ravi.v.shankar@intel.com>,
	Ramesh Thomas <ramesh.thomas@intel.com>,
	<linux-api@vger.kernel.org>, <linux-arch@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-kselftest@vger.kernel.org>
Subject: Re: [RFC PATCH 09/13] x86/uintr: Introduce vector registration and uintr_fd syscall
Date: Tue, 28 Sep 2021 13:40:30 -0700	[thread overview]
Message-ID: <c2b50159-836f-2fd4-e469-938c9dd50166@intel.com> (raw)
In-Reply-To: <87wnn6dzzn.ffs@tglx>

On 9/24/2021 3:33 AM, Thomas Gleixner wrote:
> If this ever comes back in some form, then I pretty please want the life
> time rules of this documented properly.

I'll document the life time rules for the UPID, vector and UITT next 
time. I realize now that they are quite convoluted in the current 
implementation.

I'll also fix the concurrency and serialization issues that you 
mentioned in this patch and the next one.


>
>> +	ret = task_work_add(r_info->upid_ctx->task, &r_info->twork, true);
> Care to look at the type of the third argument of task_work_add()?

Ah! I didn't realize the third argument changed a long time back.


>
>> +/*
>> + * sys_uintr_create_fd - Create a uintr_fd for the registered interrupt vector.
> So this creates a file descriptor for a vector which is already
> allocated and then it calls do_uintr_register_vector() which allocates
> the vector?

The syscall comment is misleading. Will fix it.

Vector allocation happens in userspace. The application is only expected 
to register the vector.

This syscall only creates an FD abstraction for the vector that is 
*being* registered.

>> + */
>> +SYSCALL_DEFINE2(uintr_create_fd, u64, vector, unsigned int, flags)
>> +{

Thanks,

Sohil


  reply	other threads:[~2021-09-28 20:40 UTC|newest]

Thread overview: 87+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-13 20:01 [RFC PATCH 00/13] x86 User Interrupts support Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 01/13] x86/uintr/man-page: Include man pages draft for reference Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 02/13] Documentation/x86: Add documentation for User Interrupts Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 03/13] x86/cpu: Enumerate User Interrupts support Sohil Mehta
2021-09-23 22:24   ` Thomas Gleixner
2021-09-24 19:59     ` Sohil Mehta
2021-09-27 20:42     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 04/13] x86/fpu/xstate: Enumerate User Interrupts supervisor state Sohil Mehta
2021-09-23 22:34   ` Thomas Gleixner
2021-09-27 22:25     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 05/13] x86/irq: Reserve a user IPI notification vector Sohil Mehta
2021-09-23 23:07   ` Thomas Gleixner
2021-09-25 13:30     ` Thomas Gleixner
2021-09-26 12:39       ` Thomas Gleixner
2021-09-27 19:07         ` Sohil Mehta
2021-09-28  8:11           ` Thomas Gleixner
2021-09-27 19:26     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 06/13] x86/uintr: Introduce uintr receiver syscalls Sohil Mehta
2021-09-23 12:26   ` Greg KH
2021-09-24  0:05     ` Thomas Gleixner
2021-09-27 23:20     ` Sohil Mehta
2021-09-28  4:39       ` Greg KH
2021-09-28 16:47         ` Sohil Mehta
2021-09-23 23:52   ` Thomas Gleixner
2021-09-27 23:57     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 07/13] x86/process/64: Add uintr task context switch support Sohil Mehta
2021-09-24  0:41   ` Thomas Gleixner
2021-09-28  0:30     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 08/13] x86/process/64: Clean up uintr task fork and exit paths Sohil Mehta
2021-09-24  1:02   ` Thomas Gleixner
2021-09-28  1:23     ` Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 09/13] x86/uintr: Introduce vector registration and uintr_fd syscall Sohil Mehta
2021-09-24 10:33   ` Thomas Gleixner
2021-09-28 20:40     ` Sohil Mehta [this message]
2021-09-13 20:01 ` [RFC PATCH 10/13] x86/uintr: Introduce user IPI sender syscalls Sohil Mehta
2021-09-23 12:28   ` Greg KH
2021-09-28 18:01     ` Sohil Mehta
2021-09-29  7:04       ` Greg KH
2021-09-29 14:27         ` Sohil Mehta
2021-09-24 10:54   ` Thomas Gleixner
2021-09-13 20:01 ` [RFC PATCH 11/13] x86/uintr: Introduce uintr_wait() syscall Sohil Mehta
2021-09-24 11:04   ` Thomas Gleixner
2021-09-25 12:08     ` Thomas Gleixner
2021-09-28 23:13       ` Sohil Mehta
2021-09-28 23:08     ` Sohil Mehta
2021-09-26 14:41   ` Thomas Gleixner
2021-09-29  1:09     ` Sohil Mehta
2021-09-29  3:30   ` Andy Lutomirski
2021-09-29  4:56     ` Sohil Mehta
2021-09-30 18:08       ` Andy Lutomirski
2021-09-30 19:29         ` Thomas Gleixner
2021-09-30 22:01           ` Andy Lutomirski
2021-10-01  0:01             ` Thomas Gleixner
2021-10-01  4:41               ` Andy Lutomirski
2021-10-01  9:56                 ` Thomas Gleixner
2021-10-01 15:13                   ` Andy Lutomirski
2021-10-01 18:04                     ` Sohil Mehta
2021-10-01 21:29                     ` Thomas Gleixner
2021-10-01 23:00                       ` Sohil Mehta
2021-10-01 23:04                       ` Andy Lutomirski
2021-09-13 20:01 ` [RFC PATCH 12/13] x86/uintr: Wire up the user interrupt syscalls Sohil Mehta
2021-09-13 20:01 ` [RFC PATCH 13/13] selftests/x86: Add basic tests for User IPI Sohil Mehta
2021-09-13 20:27 ` [RFC PATCH 00/13] x86 User Interrupts support Dave Hansen
2021-09-14 19:03   ` Mehta, Sohil
2021-09-23 12:19     ` Greg KH
2021-09-23 14:09       ` Greg KH
2021-09-23 14:46         ` Dave Hansen
2021-09-23 15:07           ` Greg KH
2021-09-23 23:24         ` Sohil Mehta
2021-09-23 23:09       ` Sohil Mehta
2021-09-24  0:17       ` Sohil Mehta
2021-09-23 14:39 ` Jens Axboe
2021-09-29  4:31 ` Andy Lutomirski
2021-09-30 16:30   ` Stefan Hajnoczi
2021-09-30 17:24     ` Sohil Mehta
2021-09-30 17:26       ` Andy Lutomirski
2021-10-01 16:35       ` Stefan Hajnoczi
2021-10-01 16:41         ` Richard Henderson
2021-09-30 16:26 ` Stefan Hajnoczi
2021-10-01  0:40   ` Sohil Mehta
2021-10-01  8:19 ` Pavel Machek
2021-11-18 22:19   ` Sohil Mehta
2021-11-16  3:49 ` Prakash Sangappa
2021-11-18 21:44   ` Sohil Mehta
2021-12-22 16:17 ` Chrisma Pakha
2022-01-07  2:08   ` Sohil Mehta
2022-01-17  1:14     ` Chrisma Pakha

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