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From: Peter Zijlstra <peterz@infradead.org>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Andrii Nakryiko <andrii@kernel.org>,
	linux-trace-kernel@vger.kernel.org, rostedt@goodmis.org,
	mhiramat@kernel.org, oleg@redhat.com, mingo@redhat.com,
	bpf@vger.kernel.org, jolsa@kernel.org, paulmck@kernel.org,
	clm@meta.com
Subject: Re: [PATCH v2 04/12] uprobes: revamp uprobe refcounting and lifetime management
Date: Thu, 4 Jul 2024 10:31:52 +0200	[thread overview]
Message-ID: <20240704083152.GQ11386@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CAEf4BzZQQJGrC+tCbrU90JNpXxH8-vBg_c5GzjS=FLZp0PfExA@mail.gmail.com>

On Wed, Jul 03, 2024 at 01:47:23PM -0700, Andrii Nakryiko wrote:

> > When I cobble all that together (it really shouldn't be one patch, but
> > you get the idea I hope) it looks a little something like the below.
> >
> > I *think* it should work, but perhaps I've missed something?
> 
> Well, at the very least you missed that we can't delay SRCU (or any
> other sleepable RCU flavor) potentially indefinitely for uretprobes,
> which are completely under user space control.

Sure, but that's fixable. You can work around that by having (u)tasks
with a non-empty return_instance list carry a timer. When/if that timer
fires, it goes and converts the SRCU references to actual references.

Not so very hard to do, but very much not needed for a PoC.

  parent reply	other threads:[~2024-07-04  8:32 UTC|newest]

Thread overview: 67+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-07-01 22:39 [PATCH v2 00/12] uprobes: add batched register/unregister APIs and per-CPU RW semaphore Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 01/12] uprobes: update outdated comment Andrii Nakryiko
2024-07-03 11:38   ` Oleg Nesterov
2024-07-03 18:24     ` Andrii Nakryiko
2024-07-03 21:51     ` Andrii Nakryiko
2024-07-10 13:31     ` Oleg Nesterov
2024-07-10 15:14       ` Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 02/12] uprobes: correct mmap_sem locking assumptions in uprobe_write_opcode() Andrii Nakryiko
2024-07-03 11:41   ` Oleg Nesterov
2024-07-03 13:15   ` Masami Hiramatsu
2024-07-03 18:25     ` Andrii Nakryiko
2024-07-03 21:47       ` Masami Hiramatsu
2024-07-01 22:39 ` [PATCH v2 03/12] uprobes: simplify error handling for alloc_uprobe() Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 04/12] uprobes: revamp uprobe refcounting and lifetime management Andrii Nakryiko
2024-07-02 10:22   ` Peter Zijlstra
2024-07-02 17:54     ` Andrii Nakryiko
2024-07-03 13:36   ` Peter Zijlstra
2024-07-03 20:47     ` Andrii Nakryiko
2024-07-04  8:03       ` Peter Zijlstra
2024-07-04  8:45         ` Peter Zijlstra
2024-07-04 14:40           ` Masami Hiramatsu
2024-07-04  8:31       ` Peter Zijlstra [this message]
2024-07-05 15:37   ` Oleg Nesterov
2024-07-06 17:00     ` Jiri Olsa
2024-07-06 17:05       ` Jiri Olsa
2024-07-07 14:46     ` Oleg Nesterov
2024-07-08 17:47       ` Andrii Nakryiko
2024-07-09 18:47         ` Oleg Nesterov
2024-07-09 20:59           ` Andrii Nakryiko
2024-07-09 21:31             ` Oleg Nesterov
2024-07-09 21:45               ` Andrii Nakryiko
2024-07-08 17:47     ` Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 05/12] uprobes: move offset and ref_ctr_offset into uprobe_consumer Andrii Nakryiko
2024-07-03  8:13   ` Peter Zijlstra
2024-07-03 10:13     ` Masami Hiramatsu
2024-07-03 18:23       ` Andrii Nakryiko
2024-07-07 12:48   ` Oleg Nesterov
2024-07-08 17:56     ` Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 06/12] uprobes: add batch uprobe register/unregister APIs Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 07/12] uprobes: inline alloc_uprobe() logic into __uprobe_register() Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 08/12] uprobes: split uprobe allocation and uprobes_tree insertion steps Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 09/12] uprobes: batch uprobes_treelock during registration Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 10/12] uprobes: improve lock batching for uprobe_unregister_batch Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 11/12] uprobes,bpf: switch to batch uprobe APIs for BPF multi-uprobes Andrii Nakryiko
2024-07-01 22:39 ` [PATCH v2 12/12] uprobes: switch uprobes_treelock to per-CPU RW semaphore Andrii Nakryiko
2024-07-02 10:23 ` [PATCH v2 00/12] uprobes: add batched register/unregister APIs and " Peter Zijlstra
2024-07-02 11:54   ` Peter Zijlstra
2024-07-02 12:01     ` Peter Zijlstra
2024-07-02 17:54     ` Andrii Nakryiko
2024-07-02 19:18       ` Peter Zijlstra
2024-07-02 23:56         ` Paul E. McKenney
2024-07-03  4:54           ` Andrii Nakryiko
2024-07-03  7:50           ` Peter Zijlstra
2024-07-03 14:08             ` Paul E. McKenney
2024-07-04  8:39               ` Peter Zijlstra
2024-07-04 15:13                 ` Paul E. McKenney
2024-07-03 21:57             ` Steven Rostedt
2024-07-03 22:07               ` Paul E. McKenney
2024-07-03  4:47         ` Andrii Nakryiko
2024-07-03  8:07           ` Peter Zijlstra
2024-07-03 20:55             ` Andrii Nakryiko
2024-07-03 21:33 ` Andrii Nakryiko
2024-07-04  9:15   ` Peter Zijlstra
2024-07-04 13:56     ` Steven Rostedt
2024-07-04 15:44     ` Paul E. McKenney
2024-07-08 17:47       ` Andrii Nakryiko
2024-07-08 17:48     ` Andrii Nakryiko

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