linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Waiman Long <longman@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	linux-kernel@vger.kernel.org,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
	Jann Horn <jannh@google.com>,
	Vasiliy Kulikov <segoon@openwall.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Bernd Edlinger <bernd.edlinger@hotmail.de>,
	Oleg Nesterov <oleg@redhat.com>,
	Christopher Yeoh <cyeoh@au1.ibm.com>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Sargun Dhillon <sargun@sargun.me>,
	Christian Brauner <christian.brauner@ubuntu.com>,
	Arnd Bergmann <arnd@arndb.de>,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: Re: [PATCH 2/3] rwsem: Implement down_read_interruptible
Date: Mon, 7 Dec 2020 10:33:52 -0500	[thread overview]
Message-ID: <7be81903-14e3-7485-83e7-02e65e80e8c3@redhat.com> (raw)
In-Reply-To: <20201207090243.GE3040@hirez.programming.kicks-ass.net>

On 12/7/20 4:02 AM, Peter Zijlstra wrote:
> On Thu, Dec 03, 2020 at 08:59:13PM -0500, Waiman Long wrote:
>> On 12/3/20 3:11 PM, Eric W. Biederman wrote:
>>> +static inline int __down_read_interruptible(struct rw_semaphore *sem)
>>> +{
>>> +	if (!rwsem_read_trylock(sem)) {
>>> +		if (IS_ERR(rwsem_down_read_slowpath(sem, TASK_INTERRUPTIBLE)))
>>> +			return -EINTR;
>>> +		DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem), sem);
>>> +	} else {
>>> +		rwsem_set_reader_owned(sem);
>>> +	}
>>> +	return 0;
>>> +}
>>> +
>>>    static inline int __down_read_killable(struct rw_semaphore *sem)
>>>    {
>>>    	if (!rwsem_read_trylock(sem)) {
>>> @@ -1495,6 +1507,20 @@ void __sched down_read(struct rw_semaphore *sem)
>>>    }
>>>    EXPORT_SYMBOL(down_read);
>>> +int __sched down_read_interruptible(struct rw_semaphore *sem)
>>> +{
>>> +	might_sleep();
>>> +	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
>>> +
>>> +	if (LOCK_CONTENDED_RETURN(sem, __down_read_trylock, __down_read_interruptible)) {
>>> +		rwsem_release(&sem->dep_map, _RET_IP_);
>>> +		return -EINTR;
>>> +	}
>>> +
>>> +	return 0;
>>> +}
>>> +EXPORT_SYMBOL(down_read_interruptible);
>>> +
>>>    int __sched down_read_killable(struct rw_semaphore *sem)
>>>    {
>>>    	might_sleep();
>> Acked-by: Waiman Long <longman@redhat.com>
> Yeah, that seems correct.. There's an unfortunate amount of copy-paste
> there though.
>
> Do we want to follow that up with something like this?

I am actually thinking about similar streamlining once the patch lands.

Your suggested changes look fine to me.

Cheers,
Longman



  reply	other threads:[~2020-12-07 15:35 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-03 20:09 [PATCH 0/3] exec: Transform exec_update_mutex into a rw_semaphore Eric W. Biederman
2020-12-03 20:10 ` [PATCH 1/3] rwsem: Implement down_read_killable_nested Eric W. Biederman
2020-12-04  1:58   ` Waiman Long
2020-12-09 18:38   ` [tip: locking/core] " tip-bot2 for Eric W. Biederman
2020-12-03 20:11 ` [PATCH 2/3] rwsem: Implement down_read_interruptible Eric W. Biederman
2020-12-04  1:59   ` Waiman Long
2020-12-07  9:02     ` Peter Zijlstra
2020-12-07 15:33       ` Waiman Long [this message]
2020-12-07 16:58         ` David Laight
2020-12-07 19:02           ` Waiman Long
2020-12-08  9:12             ` David Laight
2020-12-08 12:32               ` Peter Zijlstra
2020-12-08 13:13                 ` David Laight
2020-12-08 15:34               ` Waiman Long
2020-12-08 16:23                 ` David Laight
2020-12-07 15:56       ` Eric W. Biederman
2020-12-08 14:52         ` Peter Zijlstra
2020-12-08 18:27           ` Eric W. Biederman
2020-12-09 18:36             ` Peter Zijlstra
2020-12-10 19:33               ` Eric W. Biederman
2020-12-11  8:16                 ` Peter Zijlstra
2020-12-09 18:38       ` [tip: locking/core] locking/rwsem: Introduce rwsem_write_trylock() tip-bot2 for Peter Zijlstra
2020-12-09 18:38       ` [tip: locking/core] locking/rwsem: Fold __down_{read,write}*() tip-bot2 for Peter Zijlstra
2020-12-09 18:38       ` [tip: locking/core] locking/rwsem: Better collate rwsem_read_trylock() tip-bot2 for Peter Zijlstra
2020-12-09 18:38   ` [tip: locking/core] rwsem: Implement down_read_interruptible tip-bot2 for Eric W. Biederman
2020-12-03 20:12 ` [PATCH 3/3] exec: Transform exec_update_mutex into a rw_semaphore Eric W. Biederman
2020-12-04 16:08   ` Bernd Edlinger
2020-12-04 17:21     ` Linus Torvalds
2020-12-04 19:34       ` Eric W. Biederman
2020-12-04 20:10         ` Linus Torvalds
2020-12-04 20:30           ` Bernd Edlinger
2020-12-04 20:48             ` Linus Torvalds
2020-12-04 21:48               ` Davidlohr Bueso
2020-12-05 18:05                 ` Eric W. Biederman
2020-12-07  9:15                   ` Peter Zijlstra
2020-12-07  9:09               ` Peter Zijlstra
2020-12-07 18:40                 ` Linus Torvalds
2020-12-08  8:34                   ` [PATCH] perf: Break deadlock involving exec_update_mutex Peter Zijlstra
2020-12-08 18:37                     ` Linus Torvalds
2020-12-10 18:38                     ` Davidlohr Bueso
2020-12-10 19:40                       ` Eric W. Biederman
2020-12-05 17:43           ` [PATCH 3/3] exec: Transform exec_update_mutex into a rw_semaphore Eric W. Biederman
2020-12-04 17:39     ` Eric W. Biederman
2020-12-03 22:42 ` [PATCH 0/3] " Linus Torvalds
2020-12-04  1:56   ` Waiman Long
2020-12-04  4:54   ` Davidlohr Bueso

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=7be81903-14e3-7485-83e7-02e65e80e8c3@redhat.com \
    --to=longman@redhat.com \
    --cc=acme@kernel.org \
    --cc=arnd@arndb.de \
    --cc=bernd.edlinger@hotmail.de \
    --cc=christian.brauner@ubuntu.com \
    --cc=cyeoh@au1.ibm.com \
    --cc=ebiederm@xmission.com \
    --cc=gorcunov@gmail.com \
    --cc=jannh@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=sargun@sargun.me \
    --cc=segoon@openwall.com \
    --cc=torvalds@linux-foundation.org \
    --cc=viro@zeniv.linux.org.uk \
    --cc=will@kernel.org \
    /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).