From: Shakeel Butt <shakeel.butt@linux.dev>
To: JP Kobryn <jp.kobryn@linux.dev>
Cc: linux-mm@kvack.org, willy@infradead.org, usama.arif@linux.dev,
akpm@linux-foundation.org, vbabka@kernel.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: Wed, 10 Jun 2026 14:13:25 -0700 [thread overview]
Message-ID: <ainTWlyb7SIiYdeC@linux.dev> (raw)
In-Reply-To: <20260610195220.12403-1-jp.kobryn@linux.dev>
On Wed, Jun 10, 2026 at 12:52:20PM -0700, JP Kobryn wrote:
> LRU add batches can be drained before they reach capacity. This can be a
> source of LRU lock contention, but it is not currently possible to
> attribute these drains to callers with existing tracepoints.
>
> Add mm_lru_add_drain to report the CPU and lru_add batch count when an
> lru_add batch is drained. This allows tracing to distinguish full drains
> from partial drains and attribute them to the calling stack.
>
> Add mm_lru_add_drain_all to capture callers of __lru_add_drain_all and
> whether they set the force flag for all CPUs. The tracepoint resembles
> the signature of the enclosing function, but is needed because of
> potential inlining.
>
> Signed-off-by: JP Kobryn <jp.kobryn@linux.dev>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
prev parent reply other threads:[~2026-06-10 21:13 UTC|newest]
Thread overview: 3+ 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 [this message]
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