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.
Signed-off-by: Kemeng Shi <[email protected]>
---
mm/page-writeback.c | 50 +++++++++++++++++++++++++++++++++------------
1 file changed, 37 insertions(+), 13 deletions(-)
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e1f73643aca1..e4f181d52035 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -837,6 +837,41 @@ static void mdtc_calc_avail(struct dirty_throttle_control *mdtc,
mdtc->avail = filepages + min(headroom, other_clean);
}
+static inline void
+global_domain_dirty_avail(struct dirty_throttle_control *dtc, bool bg)
+{
+ dtc->avail = global_dirtyable_memory();
+ dtc->dirty = global_node_page_state(NR_FILE_DIRTY);
+ if (!bg)
+ dtc->dirty += global_node_page_state(NR_WRITEBACK);
+}
+
+static inline void
+wb_domain_dirty_avail(struct dirty_throttle_control *dtc, bool bg)
+{
+ unsigned long filepages = 0, headroom = 0, writeback = 0;
+
+ mem_cgroup_wb_stats(dtc->wb, &filepages, &headroom, &dtc->dirty,
+ &writeback);
+ if (!bg)
+ dtc->dirty += writeback;
+ mdtc_calc_avail(dtc, filepages, headroom);
+}
+
+/*
+ * 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 bg)
+{
+ struct dirty_throttle_control *gdtc = mdtc_gdtc(dtc);
+
+ if (gdtc)
+ wb_domain_dirty_avail(dtc, bg);
+ else
+ global_domain_dirty_avail(dtc, bg);
+}
+
/**
* __wb_calc_thresh - @wb's share of dirty threshold
* @dtc: dirty_throttle_context of interest
@@ -2119,14 +2154,8 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
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, true);
domain_dirty_limits(gdtc);
-
if (gdtc->dirty > gdtc->bg_thresh)
return true;
@@ -2135,13 +2164,8 @@ bool wb_over_bg_thresh(struct bdi_writeback *wb)
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, true);
domain_dirty_limits(mdtc); /* ditto, ignore writeback */
-
if (mdtc->dirty > mdtc->bg_thresh)
return true;
--
2.30.0
Hello,
On Mon, Apr 29, 2024 at 11:47:30AM +0800, Kemeng Shi wrote:
> +/*
> + * 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 bg)
I wonder whether it'd be better if the bool arg is flipped to something like
`bool include_writeback` so that it's clear what the difference is between
the two. Also, do global_domain_dirty_avail() and wb_domain_dirty_avail()
have to be separate functions? They seem trivial enough to include into the
body of domain_dirty_avail(). Are they used directly elsewhere?
> +{
> + struct dirty_throttle_control *gdtc = mdtc_gdtc(dtc);
> +
> + if (gdtc)
I know this test is used elsewhere but it isn't the most intuitive. Would it
make sense to add dtc_is_global() (or dtc_is_gdtc()) helper instead?
> + wb_domain_dirty_avail(dtc, bg);
> + else
> + global_domain_dirty_avail(dtc, bg);
> +}
Thanks.
--
tejun
on 5/2/2024 12:49 AM, Tejun Heo wrote:
> Hello,
>
> On Mon, Apr 29, 2024 at 11:47:30AM +0800, Kemeng Shi wrote:
>> +/*
>> + * 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 bg)
>
> I wonder whether it'd be better if the bool arg is flipped to something like
> `bool include_writeback` so that it's clear what the difference is between
Sure, I rename 'bool bg' to 'bool include_writeback'.
> the two. Also, do global_domain_dirty_avail() and wb_domain_dirty_avail()
> have to be separate functions? They seem trivial enough to include into the
> body of domain_dirty_avail(). Are they used directly elsewhere?
I will fold global_domain_dirty_avail() and wb_domain_dirty_avail() and
just use domain_dirty_avail.
>
>> +{
>> + struct dirty_throttle_control *gdtc = mdtc_gdtc(dtc);
>> +
>> + if (gdtc)
>
> I know this test is used elsewhere but it isn't the most intuitive. Would it
> make sense to add dtc_is_global() (or dtc_is_gdtc()) helper instead?
Will add helper dtc_is_global().
Thanks.
Kemeng
>
>> + wb_domain_dirty_avail(dtc, bg);
>> + else
>> + global_domain_dirty_avail(dtc, bg);
>> +}
>
> Thanks.
>