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From: Oleg Nesterov <oleg@redhat.com>
To: Andrii Nakryiko <andrii@kernel.org>
Cc: linux-trace-kernel@vger.kernel.org, peterz@infradead.org,
	rostedt@goodmis.org, mhiramat@kernel.org, bpf@vger.kernel.org,
	linux-kernel@vger.kernel.org, jolsa@kernel.org,
	paulmck@kernel.org
Subject: Re: [PATCH 7/8] uprobes: perform lockless SRCU-protected uprobes_tree lookup
Date: Sat, 10 Aug 2024 16:00:15 +0200	[thread overview]
Message-ID: <20240810140015.GA21800@redhat.com> (raw)
In-Reply-To: <20240808134007.GE8020@redhat.com>

On 08/08, Oleg Nesterov wrote:
>
> On 07/31, Andrii Nakryiko wrote:
> >
> >  static DEFINE_RWLOCK(uprobes_treelock);	/* serialize rbtree access */
> > +static seqcount_rwlock_t uprobes_seqcount = SEQCNT_RWLOCK_ZERO(uprobes_seqcount, &uprobes_treelock);
>
> Just noticed... Why seqcount_rwlock_t?
>
> find_uprobe_rcu() doesn't use read_seqbegin_or_lock(),
> seqcount_t should work just fine.

Please ignore... I forgot that seqcount_t is not CONFIG_PREEMPT_RT-friendly.

Hmm. __seqprop_preemptible() returns 0, this doesn't look right... Nevermend.

Oleg.


  reply	other threads:[~2024-08-10 14:00 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-31 21:42 [PATCH 0/8] uprobes: RCU-protected hot path optimizations Andrii Nakryiko
2024-07-31 21:42 ` [PATCH 1/8] rbtree: provide rb_find_rcu() / rb_find_add_rcu() Andrii Nakryiko
2024-07-31 21:42 ` [PATCH 2/8] uprobes: revamp uprobe refcounting and lifetime management Andrii Nakryiko
2024-08-01 11:09   ` Jiri Olsa
2024-08-01 16:49     ` Andrii Nakryiko
2024-08-01 22:07   ` Andrii Nakryiko
2024-08-02  8:50     ` Oleg Nesterov
2024-08-02 14:58       ` Andrii Nakryiko
2024-08-02 22:19         ` Oleg Nesterov
2024-08-02 11:11   ` Jiri Olsa
2024-08-02 15:03     ` Andrii Nakryiko
2024-08-05 13:44   ` Oleg Nesterov
2024-08-05 17:29     ` Andrii Nakryiko
2024-08-06 10:45       ` Oleg Nesterov
2024-07-31 21:42 ` [PATCH 3/8] uprobes: protected uprobe lifetime with SRCU Andrii Nakryiko
2024-08-01 12:23   ` Liao, Chang
2024-08-01 16:49     ` Andrii Nakryiko
2024-08-02  1:30       ` Liao, Chang
2024-08-05 14:51   ` Oleg Nesterov
2024-08-05 17:31     ` Andrii Nakryiko
2024-07-31 21:42 ` [PATCH 4/8] uprobes: get rid of enum uprobe_filter_ctx in uprobe filter callbacks Andrii Nakryiko
2024-07-31 21:42 ` [PATCH 5/8] uprobes: travers uprobe's consumer list locklessly under SRCU protection Andrii Nakryiko
2024-08-01 14:27   ` Jiri Olsa
2024-08-01 16:49     ` Andrii Nakryiko
2024-08-05 15:59   ` Oleg Nesterov
2024-08-05 17:31     ` Andrii Nakryiko
2024-08-06 10:54       ` Oleg Nesterov
2024-07-31 21:42 ` [PATCH 6/8] perf/uprobe: split uprobe_unregister() Andrii Nakryiko
2024-08-02  2:41   ` Liao, Chang
2024-08-02 15:05     ` Andrii Nakryiko
2024-08-05 20:01       ` Andrii Nakryiko
2024-08-06  1:50         ` Liao, Chang
2024-08-07 13:17   ` Oleg Nesterov
2024-08-07 15:24     ` Andrii Nakryiko
2024-07-31 21:42 ` [PATCH 7/8] uprobes: perform lockless SRCU-protected uprobes_tree lookup Andrii Nakryiko
2024-08-07 17:14   ` Andrii Nakryiko
2024-08-08 10:04     ` Oleg Nesterov
2024-08-08 14:29     ` Oleg Nesterov
2024-08-08 17:00       ` Andrii Nakryiko
2024-08-08 13:40   ` Oleg Nesterov
2024-08-10 14:00     ` Oleg Nesterov [this message]
2024-07-31 21:42 ` [PATCH 8/8] uprobes: switch to RCU Tasks Trace flavor for better performance Andrii Nakryiko
2024-08-01  9:35   ` Peter Zijlstra
2024-08-01 16:49     ` Andrii Nakryiko
2024-08-01 18:05     ` Paul E. McKenney
2024-08-07 13:29 ` [PATCH 0/8] uprobes: RCU-protected hot path optimizations Oleg Nesterov
2024-08-07 15:24   ` Andrii Nakryiko
2024-08-07 17:11     ` Oleg Nesterov
2024-08-07 17:31       ` Andrii Nakryiko
2024-08-07 18:24         ` Oleg Nesterov
2024-08-08  7:51         ` Liao, Chang

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