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 BEFC0268C65; Tue, 8 Apr 2025 11:29:24 +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=1744111764; cv=none; b=k4A/mp486AIptlVL82Dtx8/7bT5xF8VVU2xEc0AGgu7b0qjJ0/r9sQTVS+Yt5v06hhw+fiNyIpeiUC0GA4a/opxgEZUUpPI11jfHG+iB6VjuuzEqbiWFZGBGW+Ba1NwWYuapm1xRGQPQ2JaIj4xCNDRbX56yqrGXTMrAwojH/zA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744111764; c=relaxed/simple; bh=87iV5ymvT40tGSqam+Jc3oqE7iXFnNUT/WeWZ5cq65I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m0GCsI5kqLv0gg5UEfRKQRlkhB12cW+Lw6MMcFyo+t/8wioGxrRF38daNNFKqyZum0h8XkxZDIuJSgS9Qtv8TpkFlXT3Zlnp62DGexkp2nZoIe8au5OzOqH52+/rPiE1/vComCAFmS/U03S3qVh34D6oPLGmhxPMa8fdOhquebk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yx74MhMd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yx74MhMd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52328C4CEE5; Tue, 8 Apr 2025 11:29:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744111764; bh=87iV5ymvT40tGSqam+Jc3oqE7iXFnNUT/WeWZ5cq65I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=yx74MhMdanM3NmxUjDFVfTkXi8baCRkimlC+uteiMzFsY57eBiKALyi+IKHKSi8y2 7rH5WJdOhPj13dDLUssLrUGF8pVVAHTB4HoH0FZRghSurvTXAQOPNiBARZz158FaDJ eDQM+/9d9ZN6xP0oVy7bN/xzOFfonV1dU4VLQV10= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Tang Yizhou , Alexei Starovoitov , Christian Brauner , Steven Rostedt , Jan Kara , "Masami Hiramatsu (Google)" , "Matthew Wilcow (Oracle)" , Tejun Heo , Andrew Morton , Sasha Levin Subject: [PATCH 6.14 512/731] writeback: let trace_balance_dirty_pages() take struct dtc as parameter Date: Tue, 8 Apr 2025 12:46:49 +0200 Message-ID: <20250408104926.184904964@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250408104914.247897328@linuxfoundation.org> References: <20250408104914.247897328@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tang Yizhou [ Upstream commit f1ab2831e2a4312046bca79256b2efc41d373eaf ] Patch series "Fix calculations in trace_balance_dirty_pages() for cgwb", v2. In my experiment, I found that the output of trace_balance_dirty_pages() in the cgroup writeback scenario was strange because trace_balance_dirty_pages() always uses global_wb_domain.dirty_limit for related calculations instead of the dirty_limit of the corresponding memcg's wb_domain. The basic idea of the fix is to store the hard dirty limit value computed in wb_position_ratio() into struct dirty_throttle_control and use it for calculations in trace_balance_dirty_pages(). This patch (of 3): Currently, trace_balance_dirty_pages() already has 12 parameters. In the patch #3, I initially attempted to introduce an additional parameter. However, in include/linux/trace_events.h, bpf_trace_run12() only supports up to 12 parameters and bpf_trace_run13() does not exist. To reduce the number of parameters in trace_balance_dirty_pages(), we can make it accept a pointer to struct dirty_throttle_control as a parameter. To achieve this, we need to move the definition of struct dirty_throttle_control from mm/page-writeback.c to include/linux/writeback.h. Link: https://lkml.kernel.org/r/20250304110318.159567-1-yizhou.tang@shopee.com Link: https://lkml.kernel.org/r/20250304110318.159567-2-yizhou.tang@shopee.com Signed-off-by: Tang Yizhou Cc: Alexei Starovoitov Cc: Christian Brauner Cc: Steven Rostedt Cc: Jan Kara Cc: "Masami Hiramatsu (Google)" Cc: Matthew Wilcow (Oracle) Cc: Tang Yizhou Cc: Tejun Heo Signed-off-by: Andrew Morton Stable-dep-of: 6cc4c3aa714b ("writeback: fix calculations in trace_balance_dirty_pages() for cgwb") Signed-off-by: Sasha Levin --- include/linux/writeback.h | 23 +++++++++++++++++++++ include/trace/events/writeback.h | 16 ++++++--------- mm/page-writeback.c | 35 ++------------------------------ 3 files changed, 31 insertions(+), 43 deletions(-) diff --git a/include/linux/writeback.h b/include/linux/writeback.h index d11b903c2edb8..32095928365ce 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -313,6 +313,29 @@ static inline void cgroup_writeback_umount(struct super_block *sb) /* * mm/page-writeback.c */ +/* consolidated parameters for balance_dirty_pages() and its subroutines */ +struct dirty_throttle_control { +#ifdef CONFIG_CGROUP_WRITEBACK + struct wb_domain *dom; + struct dirty_throttle_control *gdtc; /* only set in memcg dtc's */ +#endif + struct bdi_writeback *wb; + struct fprop_local_percpu *wb_completions; + + unsigned long avail; /* dirtyable */ + unsigned long dirty; /* file_dirty + write + nfs */ + unsigned long thresh; /* dirty threshold */ + unsigned long bg_thresh; /* dirty background threshold */ + + unsigned long wb_dirty; /* per-wb counterparts */ + unsigned long wb_thresh; + unsigned long wb_bg_thresh; + + unsigned long pos_ratio; + bool freerun; + bool dirty_exceeded; +}; + void laptop_io_completion(struct backing_dev_info *info); void laptop_sync_completion(void); void laptop_mode_timer_fn(struct timer_list *t); diff --git a/include/trace/events/writeback.h b/include/trace/events/writeback.h index a261e86e61fac..3213b90237944 100644 --- a/include/trace/events/writeback.h +++ b/include/trace/events/writeback.h @@ -629,11 +629,7 @@ TRACE_EVENT(bdi_dirty_ratelimit, TRACE_EVENT(balance_dirty_pages, TP_PROTO(struct bdi_writeback *wb, - unsigned long thresh, - unsigned long bg_thresh, - unsigned long dirty, - unsigned long bdi_thresh, - unsigned long bdi_dirty, + struct dirty_throttle_control *dtc, unsigned long dirty_ratelimit, unsigned long task_ratelimit, unsigned long dirtied, @@ -641,7 +637,7 @@ TRACE_EVENT(balance_dirty_pages, long pause, unsigned long start_time), - TP_ARGS(wb, thresh, bg_thresh, dirty, bdi_thresh, bdi_dirty, + TP_ARGS(wb, dtc, dirty_ratelimit, task_ratelimit, dirtied, period, pause, start_time), @@ -664,16 +660,16 @@ TRACE_EVENT(balance_dirty_pages, ), TP_fast_assign( - unsigned long freerun = (thresh + bg_thresh) / 2; + unsigned long freerun = (dtc->thresh + dtc->bg_thresh) / 2; strscpy_pad(__entry->bdi, bdi_dev_name(wb->bdi), 32); __entry->limit = global_wb_domain.dirty_limit; __entry->setpoint = (global_wb_domain.dirty_limit + freerun) / 2; - __entry->dirty = dirty; + __entry->dirty = dtc->dirty; __entry->bdi_setpoint = __entry->setpoint * - bdi_thresh / (thresh + 1); - __entry->bdi_dirty = bdi_dirty; + dtc->wb_thresh / (dtc->thresh + 1); + __entry->bdi_dirty = dtc->wb_dirty; __entry->dirty_ratelimit = KBps(dirty_ratelimit); __entry->task_ratelimit = KBps(task_ratelimit); __entry->dirtied = dirtied; diff --git a/mm/page-writeback.c b/mm/page-writeback.c index eb55ece39c565..e980b2aec3529 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -120,29 +120,6 @@ EXPORT_SYMBOL(laptop_mode); struct wb_domain global_wb_domain; -/* consolidated parameters for balance_dirty_pages() and its subroutines */ -struct dirty_throttle_control { -#ifdef CONFIG_CGROUP_WRITEBACK - struct wb_domain *dom; - struct dirty_throttle_control *gdtc; /* only set in memcg dtc's */ -#endif - struct bdi_writeback *wb; - struct fprop_local_percpu *wb_completions; - - unsigned long avail; /* dirtyable */ - unsigned long dirty; /* file_dirty + write + nfs */ - unsigned long thresh; /* dirty threshold */ - unsigned long bg_thresh; /* dirty background threshold */ - - unsigned long wb_dirty; /* per-wb counterparts */ - unsigned long wb_thresh; - unsigned long wb_bg_thresh; - - unsigned long pos_ratio; - bool freerun; - bool dirty_exceeded; -}; - /* * Length of period for aging writeout fractions of bdis. This is an * arbitrarily chosen number. The longer the period, the slower fractions will @@ -1962,11 +1939,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb, */ if (pause < min_pause) { trace_balance_dirty_pages(wb, - sdtc->thresh, - sdtc->bg_thresh, - sdtc->dirty, - sdtc->wb_thresh, - sdtc->wb_dirty, + sdtc, dirty_ratelimit, task_ratelimit, pages_dirtied, @@ -1991,11 +1964,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb, pause: trace_balance_dirty_pages(wb, - sdtc->thresh, - sdtc->bg_thresh, - sdtc->dirty, - sdtc->wb_thresh, - sdtc->wb_dirty, + sdtc, dirty_ratelimit, task_ratelimit, pages_dirtied, -- 2.39.5