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 66A3235AC35 for ; Fri, 24 Apr 2026 10:07:50 +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=1777025270; cv=none; b=L7lkQi39BY2B5I0/Q98HDT4JRYzmyRarDh4cgbQO7PnftfSMm1h9Vy4SYJMFdEGTmnfhjtImsTHdMzHd+ZKqduq9sxRJRIPmq0wK8OfL6uvKQCiAhoL1YetHnnOPM7Hl/immph3TBZL29wmT+W5VHgsESOLY2uU1WZaUDTE/hno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777025270; c=relaxed/simple; bh=8yIKx+DpUlMEXrETL1SxO8MKLs2L9zijZFLqUGhPBbU=; h=Date:To:From:Subject:Message-Id; b=Fa5fYrXIMgO9UYUitgLvl/Vwqqe+fMOWACzsVP6Wucczla+hCCVp2o/B5ECX2r0p70UYET5vrqB6kOjTuvPG/ovXncpV0VnkQ8yTZSGXimTiwg0plZcrvdodkWOaH3o8MGdx1tJNkyb8myHIe9oEZ2quMfPUSO6bRgOB980C0Vc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=IDj8eufA; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="IDj8eufA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3B70DC19425; Fri, 24 Apr 2026 10:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1777025270; bh=8yIKx+DpUlMEXrETL1SxO8MKLs2L9zijZFLqUGhPBbU=; h=Date:To:From:Subject:From; b=IDj8eufAvaeDBx/8WiqjvbT3Xw3wr8MVl2ZwIbh6jCEN40qiIoSY+XrnhjquAgkfm 6M9Yi5HavlWobDrzwftgymqE1puFu05KjIkZjk99Q7+UKbktYIlziwyrZqlxM13lcs ATxfPdt0o9VnA2uM0+n/mCRw56xjXUAmAjcMh75g= Date: Fri, 24 Apr 2026 03:07:49 -0700 To: mm-commits@vger.kernel.org,zhengqi.arch@bytedance.com,yuanchu@google.com,weixugc@google.com,shakeel.butt@linux.dev,rostedt@goodmis.org,mhocko@kernel.org,mhiramat@kernel.org,mathieu.desnoyers@efficios.com,ljs@kernel.org,kasong@tencent.com,hannes@cmpxchg.org,david@kernel.org,baohua@kernel.org,axelrasmussen@google.com,b.suvonov@sjtu.edu.cn,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-vmscan-add-balance_pgdat-begin-end-tracepoints.patch added to mm-new branch Message-Id: <20260424100750.3B70DC19425@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/vmscan: add balance_pgdat begin/end tracepoints has been added to the -mm mm-new branch. Its filename is mm-vmscan-add-balance_pgdat-begin-end-tracepoints.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmscan-add-balance_pgdat-begin-end-tracepoints.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Bunyod Suvonov Subject: mm/vmscan: add balance_pgdat begin/end tracepoints Date: Thu, 23 Apr 2026 18:37:53 +0800 Vmscan has six main reclaim entry points: try_to_free_pages() for direct reclaim, try_to_free_mem_cgroup_pages() for memcg reclaim, mem_cgroup_shrink_node() for memcg soft limit reclaim, node_reclaim() for node reclaim, shrink_all_memory() for hibernation reclaim, and balance_pgdat() for kswapd reclaim. All of them, except for shrink_all_memory() and balance_pgdat(), already have begin/end tracepoints. This makes it harder to trace which reclaim path is responsible for memory reclaim activity, because kswapd reclaim cannot be identified as cleanly as other reclaim entry points, even though it is the main background reclaim path under memory pressure. There may be no need to trace shrink_all_memory() as it is primarily used during hibernation. So this patch adds the missing tracepoint pair for balance_pgdat(). The begin tracepoint records the node id, requested reclaim order, and the requested classzone bound (highest_zoneidx). The end tracepoint records the node id, the reclaim order that balance_pgdat() finished with, the requested classzone bound, and nr_reclaimed. Together, they show the requested reclaim order and classzone bound, whether reclaim fell back to a lower order, and how much reclaim work was done. The end tracepoint also records highest_zoneidx even though it does not change within a balance_pgdat() invocation. This keeps the end event self-contained, so users can analyze reclaim results directly from end events without depending on begin/end correlation, which is less convenient when tracing is filtered or records are dropped. It also makes it straightforward to relate nr_reclaimed and the final reclaim order to the requested classzone bound. Link: https://lore.kernel.org/20260424031418.174597-1-b.suvonov@sjtu.edu.cn Link: https://lore.kernel.org/20260423103753.546582-1-b.suvonov@sjtu.edu.cn Signed-off-by: Bunyod Suvonov Acked-by: Shakeel Butt Cc: Axel Rasmussen Cc: Barry Song Cc: David Hildenbrand Cc: Johannes Weiner Cc: Kairui Song Cc: Lorenzo Stoakes Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Michal Hocko Cc: Qi Zheng Cc: Steven Rostedt Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton --- include/trace/events/vmscan.h | 52 ++++++++++++++++++++++++++++++++ mm/vmscan.c | 5 +++ 2 files changed, 57 insertions(+) --- a/include/trace/events/vmscan.h~mm-vmscan-add-balance_pgdat-begin-end-tracepoints +++ a/include/trace/events/vmscan.h @@ -96,6 +96,58 @@ TRACE_EVENT(mm_vmscan_kswapd_wake, __entry->order) ); +TRACE_EVENT(mm_vmscan_balance_pgdat_begin, + + TP_PROTO(int nid, int order, int highest_zoneidx), + + TP_ARGS(nid, order, highest_zoneidx), + + TP_STRUCT__entry( + __field(int, nid) + __field(int, order) + __field(int, highest_zoneidx) + ), + + TP_fast_assign( + __entry->nid = nid; + __entry->order = order; + __entry->highest_zoneidx = highest_zoneidx; + ), + + TP_printk("nid=%d order=%d highest_zoneidx=%-8s", + __entry->nid, + __entry->order, + __print_symbolic(__entry->highest_zoneidx, ZONE_TYPE)) +); + +TRACE_EVENT(mm_vmscan_balance_pgdat_end, + + TP_PROTO(int nid, int order, int highest_zoneidx, + unsigned long nr_reclaimed), + + TP_ARGS(nid, order, highest_zoneidx, nr_reclaimed), + + TP_STRUCT__entry( + __field(int, nid) + __field(int, order) + __field(int, highest_zoneidx) + __field(unsigned long, nr_reclaimed) + ), + + TP_fast_assign( + __entry->nid = nid; + __entry->order = order; + __entry->highest_zoneidx = highest_zoneidx; + __entry->nr_reclaimed = nr_reclaimed; + ), + + TP_printk("nid=%d order=%d highest_zoneidx=%-8s nr_reclaimed=%lu", + __entry->nid, + __entry->order, + __print_symbolic(__entry->highest_zoneidx, ZONE_TYPE), + __entry->nr_reclaimed) +); + TRACE_EVENT(mm_vmscan_wakeup_kswapd, TP_PROTO(int nid, int zid, int order, gfp_t gfp_flags), --- a/mm/vmscan.c~mm-vmscan-add-balance_pgdat-begin-end-tracepoints +++ a/mm/vmscan.c @@ -7121,6 +7121,8 @@ static int balance_pgdat(pg_data_t *pgda .may_unmap = 1, }; + trace_mm_vmscan_balance_pgdat_begin(pgdat->node_id, order, + highest_zoneidx); set_task_reclaim_state(current, &sc.reclaim_state); psi_memstall_enter(&pflags); __fs_reclaim_acquire(_THIS_IP_); @@ -7314,6 +7316,9 @@ out: psi_memstall_leave(&pflags); set_task_reclaim_state(current, NULL); + trace_mm_vmscan_balance_pgdat_end(pgdat->node_id, sc.order, + highest_zoneidx, sc.nr_reclaimed); + /* * Return the order kswapd stopped reclaiming at as * prepare_kswapd_sleep() takes it into account. If another caller _ Patches currently in -mm which might be from b.suvonov@sjtu.edu.cn are mm-vmscan-add-balance_pgdat-begin-end-tracepoints.patch