From: Kemeng Shi <shikemeng@huaweicloud.com>
To: willy@infradead.org, akpm@linux-foundation.org, tj@kernel.org
Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v2 4/8] writeback: Factor out code of freerun to remove repeated code
Date: Tue, 14 May 2024 20:52:50 +0800 [thread overview]
Message-ID: <20240514125254.142203-5-shikemeng@huaweicloud.com> (raw)
In-Reply-To: <20240514125254.142203-1-shikemeng@huaweicloud.com>
Factor out code of freerun into new helper functions domain_poll_intv and
domain_dirty_freerun to remove repeated code.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: Tejun Heo <tj@kernel.org>
---
mm/page-writeback.c | 89 +++++++++++++++++++++++++--------------------
1 file changed, 49 insertions(+), 40 deletions(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e7c6ad48f738..b7478eacd3ff 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -139,6 +139,7 @@ struct dirty_throttle_control {
unsigned long wb_bg_thresh;
unsigned long pos_ratio;
+ bool freerun;
};
/*
@@ -1702,6 +1703,49 @@ static inline void wb_dirty_limits(struct dirty_throttle_control *dtc)
}
}
+static unsigned long domain_poll_intv(struct dirty_throttle_control *dtc,
+ bool strictlimit)
+{
+ unsigned long dirty, thresh;
+
+ if (strictlimit) {
+ dirty = dtc->wb_dirty;
+ thresh = dtc->wb_thresh;
+ } else {
+ dirty = dtc->dirty;
+ thresh = dtc->thresh;
+ }
+
+ return dirty_poll_interval(dirty, thresh);
+}
+
+/*
+ * Throttle it only when the background writeback cannot catch-up. This avoids
+ * (excessively) small writeouts when the wb limits are ramping up in case of
+ * !strictlimit.
+ *
+ * In strictlimit case make decision based on the wb counters and limits. Small
+ * writeouts when the wb limits are ramping up are the price we consciously pay
+ * for strictlimit-ing.
+ */
+static void domain_dirty_freerun(struct dirty_throttle_control *dtc,
+ bool strictlimit)
+{
+ unsigned long dirty, thresh, bg_thresh;
+
+ if (unlikely(strictlimit)) {
+ wb_dirty_limits(dtc);
+ dirty = dtc->wb_dirty;
+ thresh = dtc->wb_thresh;
+ bg_thresh = dtc->wb_bg_thresh;
+ } else {
+ dirty = dtc->dirty;
+ thresh = dtc->thresh;
+ bg_thresh = dtc->bg_thresh;
+ }
+ dtc->freerun = dirty <= dirty_freerun_ceiling(thresh, bg_thresh);
+}
+
/*
* balance_dirty_pages() must be called by processes which are generating dirty
* data. It looks at the number of dirty pages in the machine and will force
@@ -1734,27 +1778,12 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
for (;;) {
unsigned long now = jiffies;
- unsigned long dirty, thresh, bg_thresh;
- unsigned long m_dirty = 0; /* stop bogus uninit warnings */
- unsigned long m_thresh = 0;
- unsigned long m_bg_thresh = 0;
nr_dirty = global_node_page_state(NR_FILE_DIRTY);
domain_dirty_avail(gdtc, true);
domain_dirty_limits(gdtc);
-
- if (unlikely(strictlimit)) {
- wb_dirty_limits(gdtc);
-
- dirty = gdtc->wb_dirty;
- thresh = gdtc->wb_thresh;
- bg_thresh = gdtc->wb_bg_thresh;
- } else {
- dirty = gdtc->dirty;
- thresh = gdtc->thresh;
- bg_thresh = gdtc->bg_thresh;
- }
+ domain_dirty_freerun(gdtc, strictlimit);
if (mdtc) {
/*
@@ -1763,17 +1792,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
*/
domain_dirty_avail(mdtc, true);
domain_dirty_limits(mdtc);
-
- if (unlikely(strictlimit)) {
- wb_dirty_limits(mdtc);
- m_dirty = mdtc->wb_dirty;
- m_thresh = mdtc->wb_thresh;
- m_bg_thresh = mdtc->wb_bg_thresh;
- } else {
- m_dirty = mdtc->dirty;
- m_thresh = mdtc->thresh;
- m_bg_thresh = mdtc->bg_thresh;
- }
+ domain_dirty_freerun(mdtc, strictlimit);
}
/*
@@ -1790,31 +1809,21 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
wb_start_background_writeback(wb);
/*
- * Throttle it only when the background writeback cannot
- * catch-up. This avoids (excessively) small writeouts
- * when the wb limits are ramping up in case of !strictlimit.
- *
- * In strictlimit case make decision based on the wb counters
- * and limits. Small writeouts when the wb limits are ramping
- * up are the price we consciously pay for strictlimit-ing.
- *
* If memcg domain is in effect, @dirty should be under
* both global and memcg freerun ceilings.
*/
- if (dirty <= dirty_freerun_ceiling(thresh, bg_thresh) &&
- (!mdtc ||
- m_dirty <= dirty_freerun_ceiling(m_thresh, m_bg_thresh))) {
+ if (gdtc->freerun && (!mdtc || mdtc->freerun)) {
unsigned long intv;
unsigned long m_intv;
free_running:
- intv = dirty_poll_interval(dirty, thresh);
+ intv = domain_poll_intv(gdtc, strictlimit);
m_intv = ULONG_MAX;
current->dirty_paused_when = now;
current->nr_dirtied = 0;
if (mdtc)
- m_intv = dirty_poll_interval(m_dirty, m_thresh);
+ m_intv = domain_poll_intv(mdtc, strictlimit);
current->nr_dirtied_pause = min(intv, m_intv);
break;
}
--
2.30.0
next prev parent reply other threads:[~2024-05-14 12:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-14 12:52 [PATCH v2 0/8] Add helper functions to remove repeated code and improve readability of cgroup writeback Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 1/8] writeback: factor out wb_bg_dirty_limits to remove repeated code Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 2/8] writeback: add general function domain_dirty_avail to calculate dirty and avail of domain Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 3/8] writeback: factor out domain_over_bg_thresh to remove repeated code Kemeng Shi
2024-05-14 12:52 ` Kemeng Shi [this message]
2024-05-14 12:52 ` [PATCH v2 5/8] writeback: factor out wb_dirty_freerun to remove more repeated freerun code Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 6/8] writeback: factor out balance_domain_limits to remove repeated code Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 7/8] writeback: factor out wb_dirty_exceeded " Kemeng Shi
2024-05-14 12:52 ` [PATCH v2 8/8] writeback: factor out balance_wb_limits " Kemeng Shi
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