The patch titled
Subject: writeback: add general function domain_dirty_avail to calculate dirty and avail of domain
has been added to the -mm mm-unstable branch. Its filename is
writeback-add-general-function-domain_dirty_avail-to-calculate-dirty-and-avail-of-domain.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/writeback-add-general-function-domain_dirty_avail-to-calculate-dirty-and-avail-of-domain.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Subject: writeback: add general function domain_dirty_avail to calculate dirty and avail of domain
Date: Tue, 14 May 2024 20:52:48 +0800
Add general function domain_dirty_avail to calculate dirty and avail for
either dirty limit or background writeback in either global domain or wb
domain.
Link: https://lkml.kernel.org/r/20240514125254.142203-3-shikemeng@xxxxxxxxxxxxxxx
Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page-writeback.c | 65 +++++++++++++++++++++---------------------
1 file changed, 34 insertions(+), 31 deletions(-)
--- a/mm/page-writeback.c~writeback-add-general-function-domain_dirty_avail-to-calculate-dirty-and-avail-of-domain
+++ a/mm/page-writeback.c
@@ -837,6 +837,34 @@ static void mdtc_calc_avail(struct dirty
mdtc->avail = filepages + min(headroom, other_clean);
}
+static inline bool dtc_is_global(struct dirty_throttle_control *dtc)
+{
+ return mdtc_gdtc(dtc) == NULL;
+}
+
+/*
+ * Dirty background will ignore pages being written as we're trying to
+ * decide whether to put more under writeback.
+ */
+static void domain_dirty_avail(struct dirty_throttle_control *dtc,
+ bool include_writeback)
+{
+ if (dtc_is_global(dtc)) {
+ dtc->avail = global_dirtyable_memory();
+ dtc->dirty = global_node_page_state(NR_FILE_DIRTY);
+ if (include_writeback)
+ dtc->dirty += global_node_page_state(NR_WRITEBACK);
+ } else {
+ unsigned long filepages = 0, headroom = 0, writeback = 0;
+
+ mem_cgroup_wb_stats(dtc->wb, &filepages, &headroom, &dtc->dirty,
+ &writeback);
+ if (include_writeback)
+ dtc->dirty += writeback;
+ mdtc_calc_avail(dtc, filepages, headroom);
+ }
+}
+
/**
* __wb_calc_thresh - @wb's share of dirty threshold
* @dtc: dirty_throttle_context of interest
@@ -899,16 +927,9 @@ unsigned long cgwb_calc_thresh(struct bd
{
struct dirty_throttle_control gdtc = { GDTC_INIT_NO_WB };
struct dirty_throttle_control mdtc = { MDTC_INIT(wb, &gdtc) };
- unsigned long filepages = 0, headroom = 0, writeback = 0;
- gdtc.avail = global_dirtyable_memory();
- gdtc.dirty = global_node_page_state(NR_FILE_DIRTY) +
- global_node_page_state(NR_WRITEBACK);
-
- mem_cgroup_wb_stats(wb, &filepages, &headroom,
- &mdtc.dirty, &writeback);
- mdtc.dirty += writeback;
- mdtc_calc_avail(&mdtc, filepages, headroom);
+ domain_dirty_avail(&gdtc, true);
+ domain_dirty_avail(&mdtc, true);
domain_dirty_limits(&mdtc);
return __wb_calc_thresh(&mdtc, mdtc.thresh);
@@ -1719,9 +1740,8 @@ static int balance_dirty_pages(struct bd
unsigned long m_bg_thresh = 0;
nr_dirty = global_node_page_state(NR_FILE_DIRTY);
- gdtc->avail = global_dirtyable_memory();
- gdtc->dirty = nr_dirty + global_node_page_state(NR_WRITEBACK);
+ domain_dirty_avail(gdtc, true);
domain_dirty_limits(gdtc);
if (unlikely(strictlimit)) {
@@ -1737,17 +1757,11 @@ static int balance_dirty_pages(struct bd
}
if (mdtc) {
- unsigned long filepages, headroom, writeback;
-
/*
* If @wb belongs to !root memcg, repeat the same
* basic calculations for the memcg domain.
*/
- mem_cgroup_wb_stats(wb, &filepages, &headroom,
- &mdtc->dirty, &writeback);
- mdtc->dirty += writeback;
- mdtc_calc_avail(mdtc, filepages, headroom);
-
+ domain_dirty_avail(mdtc, true);
domain_dirty_limits(mdtc);
if (unlikely(strictlimit)) {
@@ -2119,14 +2133,8 @@ bool wb_over_bg_thresh(struct bdi_writeb
struct dirty_throttle_control * const mdtc = mdtc_valid(&mdtc_stor) ?
&mdtc_stor : NULL;
- /*
- * Similar to balance_dirty_pages() but ignores pages being written
- * as we're trying to decide whether to put more under writeback.
- */
- gdtc->avail = global_dirtyable_memory();
- gdtc->dirty = global_node_page_state(NR_FILE_DIRTY);
+ domain_dirty_avail(gdtc, false);
domain_dirty_limits(gdtc);
-
if (gdtc->dirty > gdtc->bg_thresh)
return true;
@@ -2135,13 +2143,8 @@ bool wb_over_bg_thresh(struct bdi_writeb
return true;
if (mdtc) {
- unsigned long filepages, headroom, writeback;
-
- mem_cgroup_wb_stats(wb, &filepages, &headroom, &mdtc->dirty,
- &writeback);
- mdtc_calc_avail(mdtc, filepages, headroom);
+ domain_dirty_avail(mdtc, false);
domain_dirty_limits(mdtc); /* ditto, ignore writeback */
-
if (mdtc->dirty > mdtc->bg_thresh)
return true;
_
Patches currently in -mm which might be from shikemeng@xxxxxxxxxxxxxxx are
writeback-factor-out-wb_bg_dirty_limits-to-remove-repeated-code.patch
writeback-add-general-function-domain_dirty_avail-to-calculate-dirty-and-avail-of-domain.patch
writeback-factor-out-domain_over_bg_thresh-to-remove-repeated-code.patch
writeback-factor-out-code-of-freerun-to-remove-repeated-code.patch
writeback-factor-out-wb_dirty_freerun-to-remove-more-repeated-freerun-code.patch
writeback-factor-out-balance_domain_limits-to-remove-repeated-code.patch
writeback-factor-out-wb_dirty_exceeded-to-remove-repeated-code.patch
writeback-factor-out-balance_wb_limits-to-remove-repeated-code.patch
