From: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
To: "David Hildenbrand (Arm)" <david@kernel.org>,
Shakeel Butt <shakeel.butt@linux.dev>
Cc: JP Kobryn <jp.kobryn@linux.dev>,
linux-mm@kvack.org, willy@infradead.org, usama.arif@linux.dev,
akpm@linux-foundation.org, mhocko@suse.com, rostedt@goodmis.org,
mhiramat@kernel.org, mathieu.desnoyers@efficios.com,
kasong@tencent.com, qi.zheng@linux.dev, baohua@kernel.org,
axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com,
chrisl@kernel.org, shikemeng@huaweicloud.com, nphamcs@gmail.com,
baoquan.he@linux.dev, youngjun.park@lge.com,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v3] mm/lruvec: trace LRU add drains and drain-all requests
Date: Thu, 18 Jun 2026 10:30:27 +0200 [thread overview]
Message-ID: <bbcb6db5-6a01-46b7-979f-dadd52a5176f@kernel.org> (raw)
In-Reply-To: <3149bc84-dd3a-43ba-826e-6364965fdafd@kernel.org>
On 6/18/26 10:21, David Hildenbrand (Arm) wrote:
> On 6/17/26 20:18, Vlastimil Babka (SUSE) wrote:
>> On 6/17/26 17:03, Shakeel Butt wrote:
>>> On Wed, Jun 17, 2026 at 01:11:16PM +0200, David Hildenbrand (Arm) wrote:
>>>>
>>>> Given that trace events can quickly become stable ABI [1], are we really sure we
>>>> want to add this?
>>>
>>> Yes, I think so as this is useful to get insights into lru cache draining.
>>> Trace events being stable or not is secondary IMHO. If in future we rearchitect
>>> the lru page handling where there is no cache draining anymore, we can make
>>> these a noops.
>>
>> Yeah and I don't recall ever that a change to a mm tracepoint would ever
>> break someone who'd complain and we'd have to revert it.
> Really? :)
>
> Read the context of the link I posted once more.
Ah, I see. I've only read the single mail from Steven that referred to the
old powertop breakage and didn't notice the context.
But I don't think these worries should stop us from adding easily usable
tracepoints.
prev parent reply other threads:[~2026-06-18 8:48 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-10 19:52 [PATCH v3] mm/lruvec: trace LRU add drains and drain-all requests JP Kobryn
2026-06-10 21:03 ` Barry Song
2026-06-10 21:13 ` Shakeel Butt
2026-06-17 11:11 ` David Hildenbrand (Arm)
2026-06-17 15:03 ` Shakeel Butt
2026-06-17 18:18 ` Vlastimil Babka (SUSE)
2026-06-18 8:21 ` David Hildenbrand (Arm)
2026-06-18 8:30 ` Vlastimil Babka (SUSE) [this message]
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