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From: "Daniel Walker (danielwa)" <danielwa@cisco.com>
To: Oleg Nesterov <oleg@redhat.com>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>,
	"Darko Tominac -X (dtominac - GLOBALLOGIC INC at Cisco)"
	<dtominac@cisco.com>, Masami Hiramatsu <mhiramat@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Namhyung Kim <namhyung@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>, Ian Rogers <irogers@google.com>,
	Adrian Hunter <adrian.hunter@intel.com>,
	James Clark <james.clark@linaro.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Liam R. Howlett" <Liam.Howlett@oracle.com>,
	Lorenzo Stoakes <ljs@kernel.org>,
	Vlastimil Babka <vbabka@kernel.org>, Jann Horn <jannh@google.com>,
	"xe-linux-external(mailer list)" <xe-linux-external@cisco.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-trace-kernel@vger.kernel.org"
	<linux-trace-kernel@vger.kernel.org>,
	"linux-perf-users@vger.kernel.org"
	<linux-perf-users@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>
Subject: Re: [PATCH] mm/madvise: preserve uprobe breakpoints across MADV_DONTNEED
Date: Wed, 29 Apr 2026 21:11:08 +0000	[thread overview]
Message-ID: <afJz3l6435DHLorn@goliath> (raw)
In-Reply-To: <afIiqR5CqYRId0N0@redhat.com>

On Wed, Apr 29, 2026 at 05:24:25PM +0200, Oleg Nesterov wrote:
> On 04/29, David Hildenbrand (Arm) wrote:
> >
> > On 4/29/26 15:15, Darko Tominac wrote:
> >
> > > uprobe infrastructure does not re-instrument pages on individual page
> > > faults (uprobe_mmap() is only called during VMA creation, not on
> > > page-in), the breakpoints are silently lost once the discarded pages are
> > > re-read from the backing file.  The probes stop firing with no error
> > > indication, and the only recovery is to unregister and re-register the
> > > affected uprobes.
> >
> > Right. Don't MADV_DONTNEED uprobes, just like you are not supposed to
> > MADV_DONTNEED debugger breakpoints/set data etc. :)
> 
> Agreed, thanks.


Shouldn't there be some sort of compensation or notification for this, or is each person that
hits this suppose to just scratch their head and send a patch that's rejected?

Daniel

  reply	other threads:[~2026-04-29 21:12 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-29 13:15 [PATCH] mm/madvise: preserve uprobe breakpoints across MADV_DONTNEED Darko Tominac
2026-04-29 13:31 ` David Hildenbrand (Arm)
2026-04-29 15:24   ` Oleg Nesterov
2026-04-29 21:11     ` Daniel Walker (danielwa) [this message]
2026-04-30  9:16       ` Oleg Nesterov
2026-04-30  9:54         ` David Hildenbrand (Arm)
2026-04-30 18:46           ` Oleg Nesterov
2026-04-30 19:11             ` Jann Horn
2026-04-30 15:22       ` Jann Horn
2026-04-30 19:25         ` Daniel Walker (danielwa)

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