From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E78434CFBA for ; Mon, 23 Feb 2026 23:30:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771889421; cv=none; b=lIJhU4hpV6RhQo+iR7ItdnZaAMdy63WC/02l1z7Ys+ks7naBxNQf2riWGxqcEN+KRc3DPJc8NJ9VIoqR8ktM7VGP0ZnD6kYO3/bOBpdswR/c7im3oCaU+/Y58hJ/qUlq4Avx9OasH3F2sQbU40g6m+LJ7Z9yqklsq58hMj4TBoQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771889421; c=relaxed/simple; bh=Glie2dDdb0rtYRRJaB/UrvAAGXrFPRVG05iXdt9Zf5g=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=iFBDBDUjW7G4WJX9NNKtYnBmTSV8xv3OBSGocxxpWx0LNWas7Wb2P8x4qEbCGCVnjbclIYwyrDHlSp4A910m7K7lHrO/5H1TK/FyEDf/R9GJRdTX/Jzh1WFZkVAypWw5AAT2h8ds0BB3qYDH4QZdCCJLwLMyBGbmL1pg9sPBGdo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XQplAEaz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XQplAEaz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A74EC116C6; Mon, 23 Feb 2026 23:30:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771889420; bh=Glie2dDdb0rtYRRJaB/UrvAAGXrFPRVG05iXdt9Zf5g=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=XQplAEaznmMrCJ6SgkIq5wf0WtoJXumBiFEkgJe3OJQ3oqPctce0aW2nZYm4W0EV9 EVEO6T6DZvaJkJgtRoQyey8sILh+2X1ppdtZjMdrzAGFlgVw5d/v3kZMlYTHDgsN+p e8XlPGTWv/0KH1oAVE/w9LK0MVoGRmZer55PopAVjX7qKAqIHUVX2QEaYZXvWA6hb3 LGby9WFIxqBZGFQxusZvD7q4PWlHUViAjzwCThkhysUMWQ2dJMEPFGZAw6T2f3z+o1 XLiPlOrX5K+2qxV3cSreRHlukrKItI+ujzkNpCxKnQDEVXgfm/L3e3nH6lJi7uhNqu PUuFrnPj9xacQ== Date: Tue, 24 Feb 2026 08:30:14 +0900 From: Masami Hiramatsu (Google) To: Thomas Ballasi Cc: akpm@linux-foundation.org, axelrasmussen@google.com, david@kernel.org, hannes@cmpxchg.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, mhiramat@kernel.org, mhocko@kernel.org, rostedt@goodmis.org, shakeel.butt@linux.dev, weixugc@google.com, yuanchu@google.com, zhengqi.arch@bytedance.com Subject: Re: [PATCH v7 3/3] mm: vmscan: add PIDs to vmscan tracepoints Message-Id: <20260224083014.66bf222ffd81a3ebaa57a0e0@kernel.org> In-Reply-To: <20260223171544.4750-4-tballasi@linux.microsoft.com> References: <20260213181537.54350-1-tballasi@linux.microsoft.com> <20260223171544.4750-1-tballasi@linux.microsoft.com> <20260223171544.4750-4-tballasi@linux.microsoft.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Hi, On Mon, 23 Feb 2026 09:15:44 -0800 Thomas Ballasi wrote: > The changes aims at adding additionnal tracepoints variables to help > debuggers attribute them to specific processes. > > The PID field uses in_task() to reliably detect when we're in process > context and can safely access current->pid. When not in process > context (such as in interrupt or in an asynchronous RCU context), the > field is set to -1 as a sentinel value. > > Signed-off-by: Thomas Ballasi > --- > include/trace/events/vmscan.h | 34 +++++++++++++++++++++++++--------- > 1 file changed, 25 insertions(+), 9 deletions(-) > > diff --git a/include/trace/events/vmscan.h b/include/trace/events/vmscan.h > index 1212f6a7c223e..15b31281f0955 100644 > --- a/include/trace/events/vmscan.h > +++ b/include/trace/events/vmscan.h > @@ -122,18 +122,22 @@ DECLARE_EVENT_CLASS(mm_vmscan_direct_reclaim_begin_template, > __field( unsigned long, gfp_flags ) > __field( u64, memcg_id ) > __field( int, order ) > + __field( int, pid ) > ), > > TP_fast_assign( > __entry->gfp_flags = (__force unsigned long)gfp_flags; > __entry->order = order; > + __entry->pid = current->pid; All entries saves current->pid in common_pid field. Can you use this common field? # cat events/vmscan/mm_vmscan_reclaim_pages/format name: mm_vmscan_reclaim_pages ID: 590 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; ## <------------here field:int nid; offset:8; size:4; signed:1; field:unsigned long nr_scanned; offset:16; size:8; signed:0; field:unsigned long nr_reclaimed; offset:24; size:8; signed:0; field:unsigned long nr_dirty; offset:32; size:8; signed:0; field:unsigned long nr_writeback; offset:40; size:8; signed:0; field:unsigned long nr_congested; offset:48; size:8; signed:0; field:unsigned long nr_immediate; offset:56; size:8; signed:0; field:unsigned int nr_activate0; offset:64; size:4; signed:0; field:unsigned int nr_activate1; offset:68; size:4; signed:0; field:unsigned long nr_ref_keep; offset:72; size:8; signed:0; field:unsigned long nr_unmap_fail; offset:80; size:8; signed:0; Thank you, -- Masami Hiramatsu (Google)