| Message ID | 20240422164808.13627-3-shikemeng@huaweicloud.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Improve visibility of writeback | expand |
Hello, On Tue, Apr 23, 2024 at 12:48:06AM +0800, Kemeng Shi wrote: > Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats > of bdi. > > Following domain hierarchy is tested: > global domain (320G) > / \ > cgroup domain1(10G) cgroup domain2(10G) > | | > bdi wb1 wb2 > > /* per wb writeback info of bdi is collected */ > cat /sys/kernel/debug/bdi/252:16/wb_stats > WbCgIno: 1 > WbWriteback: 0 kB > WbReclaimable: 0 kB > WbDirtyThresh: 0 kB > WbDirtied: 0 kB > WbWritten: 0 kB > WbWriteBandwidth: 102400 kBps > b_dirty: 0 > b_io: 0 > b_more_io: 0 > b_dirty_time: 0 > state: 1 > WbCgIno: 4094 > WbWriteback: 54432 kB > WbReclaimable: 766080 kB > WbDirtyThresh: 3094760 kB > WbDirtied: 1656480 kB > WbWritten: 837088 kB > WbWriteBandwidth: 132772 kBps > b_dirty: 1 > b_io: 1 > b_more_io: 0 > b_dirty_time: 0 > state: 7 > WbCgIno: 4135 > WbWriteback: 15232 kB > WbReclaimable: 786688 kB > WbDirtyThresh: 2909984 kB > WbDirtied: 1482656 kB > WbWritten: 681408 kB > WbWriteBandwidth: 124848 kBps > b_dirty: 0 > b_io: 1 > b_more_io: 0 > b_dirty_time: 0 > state: 7 > > Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Maybe it'd be useful to delineate each wb better in the output? It's a bit difficult to parse visually. Other than that, Acked-by: Tejun Heo <tj@kernel.org> Thanks.
Hi Kemeng, On Tue, 23 Apr 2024 00:48:06 +0800 Kemeng Shi <shikemeng@huaweicloud.com> wrote: > Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats > of bdi. > > Following domain hierarchy is tested: > global domain (320G) > / \ > cgroup domain1(10G) cgroup domain2(10G) > | | > bdi wb1 wb2 > > /* per wb writeback info of bdi is collected */ > cat /sys/kernel/debug/bdi/252:16/wb_stats > WbCgIno: 1 > WbWriteback: 0 kB > WbReclaimable: 0 kB > WbDirtyThresh: 0 kB > WbDirtied: 0 kB > WbWritten: 0 kB > WbWriteBandwidth: 102400 kBps > b_dirty: 0 > b_io: 0 > b_more_io: 0 > b_dirty_time: 0 > state: 1 > WbCgIno: 4094 > WbWriteback: 54432 kB > WbReclaimable: 766080 kB > WbDirtyThresh: 3094760 kB > WbDirtied: 1656480 kB > WbWritten: 837088 kB > WbWriteBandwidth: 132772 kBps > b_dirty: 1 > b_io: 1 > b_more_io: 0 > b_dirty_time: 0 > state: 7 > WbCgIno: 4135 > WbWriteback: 15232 kB > WbReclaimable: 786688 kB > WbDirtyThresh: 2909984 kB > WbDirtied: 1482656 kB > WbWritten: 681408 kB > WbWriteBandwidth: 124848 kBps > b_dirty: 0 > b_io: 1 > b_more_io: 0 > b_dirty_time: 0 > state: 7 > > Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> > --- > include/linux/writeback.h | 1 + > mm/backing-dev.c | 78 ++++++++++++++++++++++++++++++++++++++- > mm/page-writeback.c | 19 ++++++++++ > 3 files changed, 96 insertions(+), 2 deletions(-) > > diff --git a/include/linux/writeback.h b/include/linux/writeback.h > index 9845cb62e40b..112d806ddbe4 100644 > --- a/include/linux/writeback.h > +++ b/include/linux/writeback.h > @@ -355,6 +355,7 @@ int dirtytime_interval_handler(struct ctl_table *table, int write, > > void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); > unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); > +unsigned long cgwb_calc_thresh(struct bdi_writeback *wb); > > void wb_update_bandwidth(struct bdi_writeback *wb); > > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > index 089146feb830..6ecd11bdce6e 100644 > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -155,19 +155,93 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) > } > DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats); > > +static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, > + struct wb_stats *stats) > +{ > + > + seq_printf(m, > + "WbCgIno: %10lu\n" > + "WbWriteback: %10lu kB\n" > + "WbReclaimable: %10lu kB\n" > + "WbDirtyThresh: %10lu kB\n" > + "WbDirtied: %10lu kB\n" > + "WbWritten: %10lu kB\n" > + "WbWriteBandwidth: %10lu kBps\n" > + "b_dirty: %10lu\n" > + "b_io: %10lu\n" > + "b_more_io: %10lu\n" > + "b_dirty_time: %10lu\n" > + "state: %10lx\n\n", > + cgroup_ino(wb->memcg_css->cgroup), I'm getting below kunit build failure from the latest mm-unstable tree, and 'git bisect' points this patch. ERROR:root:.../linux/mm/backing-dev.c: In function ‘wb_stats_show’: .../linux/mm/backing-dev.c:175:20: error: implicit declaration of function ‘cgroup_ino’; did you mean ‘cgroup_init’? [-Werror=implicit-function-declaration] 175 | cgroup_ino(wb->memcg_css->cgroup), | ^~~~~~~~~~ | cgroup_init .../linux/mm/backing-dev.c:175:33: error: ‘struct bdi_writeback’ has no member named ‘memcg_css’ 175 | cgroup_ino(wb->memcg_css->cgroup), | ^~ The kunit build config is not having CONFIG_CGROUPS. I guess we need to check the case? I confirmed below dumb change is fixing the issue, but I guess it could be cleaner. May I ask your opinion? --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -160,7 +160,9 @@ static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, { seq_printf(m, +#ifdef CONFIG_CGROUPS "WbCgIno: %10lu\n" +#endif "WbWriteback: %10lu kB\n" "WbReclaimable: %10lu kB\n" "WbDirtyThresh: %10lu kB\n" @@ -172,7 +174,9 @@ static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, "b_more_io: %10lu\n" "b_dirty_time: %10lu\n" "state: %10lx\n\n", +#ifdef CONFIG_CGROUPS cgroup_ino(wb->memcg_css->cgroup), +#endif K(stats->nr_writeback), K(stats->nr_reclaimable), K(stats->wb_thresh), > + K(stats->nr_writeback), > + K(stats->nr_reclaimable), > + K(stats->wb_thresh), > + K(stats->nr_dirtied), > + K(stats->nr_written), > + K(wb->avg_write_bandwidth), > + stats->nr_dirty, > + stats->nr_io, > + stats->nr_more_io, > + stats->nr_dirty_time, > + wb->state); > +} > + > +static int cgwb_debug_stats_show(struct seq_file *m, void *v) > +{ > + struct backing_dev_info *bdi = m->private; > + unsigned long background_thresh; > + unsigned long dirty_thresh; > + struct bdi_writeback *wb; > + struct wb_stats stats; Kunit build also shows below warning: .../linux/mm/backing-dev.c: In function ‘cgwb_debug_stats_show’: .../linux/mm/backing-dev.c:195:25: warning: unused variable ‘stats’ [-Wunused-variable] 195 | struct wb_stats stats; | ^~~~~ I guess above line can simply removed? > + > + global_dirty_limits(&background_thresh, &dirty_thresh); > + > + rcu_read_lock(); > + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) { > + struct wb_stats stats = { .dirty_thresh = dirty_thresh }; > + > + if (!wb_tryget(wb)) > + continue; > + > + collect_wb_stats(&stats, wb); > + > + /* > + * Calculate thresh of wb in writeback cgroup which is min of > + * thresh in global domain and thresh in cgroup domain. Drop > + * rcu lock because cgwb_calc_thresh may sleep in > + * cgroup_rstat_flush. We can do so here because we have a ref. > + */ > + if (mem_cgroup_wb_domain(wb)) { > + rcu_read_unlock(); > + stats.wb_thresh = min(stats.wb_thresh, cgwb_calc_thresh(wb)); > + rcu_read_lock(); > + } > + > + wb_stats_show(m, wb, &stats); > + > + wb_put(wb); > + } > + rcu_read_unlock(); > + > + return 0; > +} Thanks, SJ [...]
on 4/23/2024 2:32 AM, Tejun Heo wrote: > Hello, > > On Tue, Apr 23, 2024 at 12:48:06AM +0800, Kemeng Shi wrote: >> Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats >> of bdi. >> >> Following domain hierarchy is tested: >> global domain (320G) >> / \ >> cgroup domain1(10G) cgroup domain2(10G) >> | | >> bdi wb1 wb2 >> >> /* per wb writeback info of bdi is collected */ >> cat /sys/kernel/debug/bdi/252:16/wb_stats >> WbCgIno: 1 >> WbWriteback: 0 kB >> WbReclaimable: 0 kB >> WbDirtyThresh: 0 kB >> WbDirtied: 0 kB >> WbWritten: 0 kB >> WbWriteBandwidth: 102400 kBps >> b_dirty: 0 >> b_io: 0 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 1 >> WbCgIno: 4094 >> WbWriteback: 54432 kB >> WbReclaimable: 766080 kB >> WbDirtyThresh: 3094760 kB >> WbDirtied: 1656480 kB >> WbWritten: 837088 kB >> WbWriteBandwidth: 132772 kBps >> b_dirty: 1 >> b_io: 1 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 7 >> WbCgIno: 4135 >> WbWriteback: 15232 kB >> WbReclaimable: 786688 kB >> WbDirtyThresh: 2909984 kB >> WbDirtied: 1482656 kB >> WbWritten: 681408 kB >> WbWriteBandwidth: 124848 kBps >> b_dirty: 0 >> b_io: 1 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 7 >> >> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> > > Maybe it'd be useful to delineate each wb better in the output? It's a bit > difficult to parse visually. Other than that, Sorry for this. A blank line was added at end of each wb in this patch but I forgot to update the changelog. As there is some kunit build problem reported, I will correct changelog with the fix to build problem. Thanks a lot for review. Kemeng > > Acked-by: Tejun Heo <tj@kernel.org> > > Thanks. >
Hello on 4/23/2024 8:44 AM, SeongJae Park wrote: > Hi Kemeng, > > On Tue, 23 Apr 2024 00:48:06 +0800 Kemeng Shi <shikemeng@huaweicloud.com> wrote: > >> Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats >> of bdi. >> >> Following domain hierarchy is tested: >> global domain (320G) >> / \ >> cgroup domain1(10G) cgroup domain2(10G) >> | | >> bdi wb1 wb2 >> >> /* per wb writeback info of bdi is collected */ >> cat /sys/kernel/debug/bdi/252:16/wb_stats >> WbCgIno: 1 >> WbWriteback: 0 kB >> WbReclaimable: 0 kB >> WbDirtyThresh: 0 kB >> WbDirtied: 0 kB >> WbWritten: 0 kB >> WbWriteBandwidth: 102400 kBps >> b_dirty: 0 >> b_io: 0 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 1 >> WbCgIno: 4094 >> WbWriteback: 54432 kB >> WbReclaimable: 766080 kB >> WbDirtyThresh: 3094760 kB >> WbDirtied: 1656480 kB >> WbWritten: 837088 kB >> WbWriteBandwidth: 132772 kBps >> b_dirty: 1 >> b_io: 1 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 7 >> WbCgIno: 4135 >> WbWriteback: 15232 kB >> WbReclaimable: 786688 kB >> WbDirtyThresh: 2909984 kB >> WbDirtied: 1482656 kB >> WbWritten: 681408 kB >> WbWriteBandwidth: 124848 kBps >> b_dirty: 0 >> b_io: 1 >> b_more_io: 0 >> b_dirty_time: 0 >> state: 7 >> >> Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> >> --- >> include/linux/writeback.h | 1 + >> mm/backing-dev.c | 78 ++++++++++++++++++++++++++++++++++++++- >> mm/page-writeback.c | 19 ++++++++++ >> 3 files changed, 96 insertions(+), 2 deletions(-) >> >> diff --git a/include/linux/writeback.h b/include/linux/writeback.h >> index 9845cb62e40b..112d806ddbe4 100644 >> --- a/include/linux/writeback.h >> +++ b/include/linux/writeback.h >> @@ -355,6 +355,7 @@ int dirtytime_interval_handler(struct ctl_table *table, int write, >> >> void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); >> unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); >> +unsigned long cgwb_calc_thresh(struct bdi_writeback *wb); >> >> void wb_update_bandwidth(struct bdi_writeback *wb); >> >> diff --git a/mm/backing-dev.c b/mm/backing-dev.c >> index 089146feb830..6ecd11bdce6e 100644 >> --- a/mm/backing-dev.c >> +++ b/mm/backing-dev.c >> @@ -155,19 +155,93 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) >> } >> DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats); >> >> +static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, >> + struct wb_stats *stats) >> +{ >> + >> + seq_printf(m, >> + "WbCgIno: %10lu\n" >> + "WbWriteback: %10lu kB\n" >> + "WbReclaimable: %10lu kB\n" >> + "WbDirtyThresh: %10lu kB\n" >> + "WbDirtied: %10lu kB\n" >> + "WbWritten: %10lu kB\n" >> + "WbWriteBandwidth: %10lu kBps\n" >> + "b_dirty: %10lu\n" >> + "b_io: %10lu\n" >> + "b_more_io: %10lu\n" >> + "b_dirty_time: %10lu\n" >> + "state: %10lx\n\n", >> + cgroup_ino(wb->memcg_css->cgroup), > > I'm getting below kunit build failure from the latest mm-unstable tree, and > 'git bisect' points this patch. > > ERROR:root:.../linux/mm/backing-dev.c: In function ‘wb_stats_show’: > .../linux/mm/backing-dev.c:175:20: error: implicit declaration of function ‘cgroup_ino’; did you mean ‘cgroup_init’? [-Werror=implicit-function-declaration] > 175 | cgroup_ino(wb->memcg_css->cgroup), > | ^~~~~~~~~~ > | cgroup_init > .../linux/mm/backing-dev.c:175:33: error: ‘struct bdi_writeback’ has no member named ‘memcg_css’ > 175 | cgroup_ino(wb->memcg_css->cgroup), > | ^~ > > The kunit build config is not having CONFIG_CGROUPS. I guess we need to check > the case? I confirmed below dumb change is fixing the issue, but I guess it > could be cleaner. May I ask your opinion? Thanks for report the issue. As discussed before, we try to keep the same output whether CGROUP is enable or not. So we'd better show cgroup number 0 for bdi->wb instead remove cgroup number from output. > > --- a/mm/backing-dev.c > +++ b/mm/backing-dev.c > @@ -160,7 +160,9 @@ static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, > { > > seq_printf(m, > +#ifdef CONFIG_CGROUPS > "WbCgIno: %10lu\n" > +#endif > "WbWriteback: %10lu kB\n" > "WbReclaimable: %10lu kB\n" > "WbDirtyThresh: %10lu kB\n" > @@ -172,7 +174,9 @@ static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, > "b_more_io: %10lu\n" > "b_dirty_time: %10lu\n" > "state: %10lx\n\n", > +#ifdef CONFIG_CGROUPS > cgroup_ino(wb->memcg_css->cgroup), > +#endif > K(stats->nr_writeback), > K(stats->nr_reclaimable), > K(stats->wb_thresh), > > >> + K(stats->nr_writeback), >> + K(stats->nr_reclaimable), >> + K(stats->wb_thresh), >> + K(stats->nr_dirtied), >> + K(stats->nr_written), >> + K(wb->avg_write_bandwidth), >> + stats->nr_dirty, >> + stats->nr_io, >> + stats->nr_more_io, >> + stats->nr_dirty_time, >> + wb->state); >> +} >> + >> +static int cgwb_debug_stats_show(struct seq_file *m, void *v) >> +{ >> + struct backing_dev_info *bdi = m->private; >> + unsigned long background_thresh; >> + unsigned long dirty_thresh; >> + struct bdi_writeback *wb; >> + struct wb_stats stats; > > Kunit build also shows below warning: > > .../linux/mm/backing-dev.c: In function ‘cgwb_debug_stats_show’: > .../linux/mm/backing-dev.c:195:25: warning: unused variable ‘stats’ [-Wunused-variable] > 195 | struct wb_stats stats; > | ^~~~~ > > I guess above line can simply removed? Yes, this could be simply removed. I'd submit a new series to fix this very soon. Thanks. > >> + >> + global_dirty_limits(&background_thresh, &dirty_thresh); >> + >> + rcu_read_lock(); >> + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) { >> + struct wb_stats stats = { .dirty_thresh = dirty_thresh }; >> + >> + if (!wb_tryget(wb)) >> + continue; >> + >> + collect_wb_stats(&stats, wb); >> + >> + /* >> + * Calculate thresh of wb in writeback cgroup which is min of >> + * thresh in global domain and thresh in cgroup domain. Drop >> + * rcu lock because cgwb_calc_thresh may sleep in >> + * cgroup_rstat_flush. We can do so here because we have a ref. >> + */ >> + if (mem_cgroup_wb_domain(wb)) { >> + rcu_read_unlock(); >> + stats.wb_thresh = min(stats.wb_thresh, cgwb_calc_thresh(wb)); >> + rcu_read_lock(); >> + } >> + >> + wb_stats_show(m, wb, &stats); >> + >> + wb_put(wb); >> + } >> + rcu_read_unlock(); >> + >> + return 0; >> +} > > > Thanks, > SJ > > [...] >
diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 9845cb62e40b..112d806ddbe4 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -355,6 +355,7 @@ int dirtytime_interval_handler(struct ctl_table *table, int write, void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty); unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh); +unsigned long cgwb_calc_thresh(struct bdi_writeback *wb); void wb_update_bandwidth(struct bdi_writeback *wb); diff --git a/mm/backing-dev.c b/mm/backing-dev.c index 089146feb830..6ecd11bdce6e 100644 --- a/mm/backing-dev.c +++ b/mm/backing-dev.c @@ -155,19 +155,93 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) } DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats); +static void wb_stats_show(struct seq_file *m, struct bdi_writeback *wb, + struct wb_stats *stats) +{ + + seq_printf(m, + "WbCgIno: %10lu\n" + "WbWriteback: %10lu kB\n" + "WbReclaimable: %10lu kB\n" + "WbDirtyThresh: %10lu kB\n" + "WbDirtied: %10lu kB\n" + "WbWritten: %10lu kB\n" + "WbWriteBandwidth: %10lu kBps\n" + "b_dirty: %10lu\n" + "b_io: %10lu\n" + "b_more_io: %10lu\n" + "b_dirty_time: %10lu\n" + "state: %10lx\n\n", + cgroup_ino(wb->memcg_css->cgroup), + K(stats->nr_writeback), + K(stats->nr_reclaimable), + K(stats->wb_thresh), + K(stats->nr_dirtied), + K(stats->nr_written), + K(wb->avg_write_bandwidth), + stats->nr_dirty, + stats->nr_io, + stats->nr_more_io, + stats->nr_dirty_time, + wb->state); +} + +static int cgwb_debug_stats_show(struct seq_file *m, void *v) +{ + struct backing_dev_info *bdi = m->private; + unsigned long background_thresh; + unsigned long dirty_thresh; + struct bdi_writeback *wb; + struct wb_stats stats; + + global_dirty_limits(&background_thresh, &dirty_thresh); + + rcu_read_lock(); + list_for_each_entry_rcu(wb, &bdi->wb_list, bdi_node) { + struct wb_stats stats = { .dirty_thresh = dirty_thresh }; + + if (!wb_tryget(wb)) + continue; + + collect_wb_stats(&stats, wb); + + /* + * Calculate thresh of wb in writeback cgroup which is min of + * thresh in global domain and thresh in cgroup domain. Drop + * rcu lock because cgwb_calc_thresh may sleep in + * cgroup_rstat_flush. We can do so here because we have a ref. + */ + if (mem_cgroup_wb_domain(wb)) { + rcu_read_unlock(); + stats.wb_thresh = min(stats.wb_thresh, cgwb_calc_thresh(wb)); + rcu_read_lock(); + } + + wb_stats_show(m, wb, &stats); + + wb_put(wb); + } + rcu_read_unlock(); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(cgwb_debug_stats); + static void bdi_debug_register(struct backing_dev_info *bdi, const char *name) { bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root); debugfs_create_file("stats", 0444, bdi->debug_dir, bdi, &bdi_debug_stats_fops); + debugfs_create_file("wb_stats", 0444, bdi->debug_dir, bdi, + &cgwb_debug_stats_fops); } static void bdi_debug_unregister(struct backing_dev_info *bdi) { debugfs_remove_recursive(bdi->debug_dir); } -#else +#else /* CONFIG_DEBUG_FS */ static inline void bdi_debug_init(void) { } @@ -178,7 +252,7 @@ static inline void bdi_debug_register(struct backing_dev_info *bdi, static inline void bdi_debug_unregister(struct backing_dev_info *bdi) { } -#endif +#endif /* CONFIG_DEBUG_FS */ static ssize_t read_ahead_kb_store(struct device *dev, struct device_attribute *attr, diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 3e19b87049db..3bb3bed102ef 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -892,6 +892,25 @@ unsigned long wb_calc_thresh(struct bdi_writeback *wb, unsigned long thresh) return __wb_calc_thresh(&gdtc); } +unsigned long cgwb_calc_thresh(struct bdi_writeback *wb) +{ + 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_limits(&mdtc); + + return __wb_calc_thresh(&mdtc); +} + /* * setpoint - dirty 3 * f(dirty) := 1.0 + (----------------)
Add /sys/kernel/debug/bdi/xxx/wb_stats to show per group writeback stats of bdi. Following domain hierarchy is tested: global domain (320G) / \ cgroup domain1(10G) cgroup domain2(10G) | | bdi wb1 wb2 /* per wb writeback info of bdi is collected */ cat /sys/kernel/debug/bdi/252:16/wb_stats WbCgIno: 1 WbWriteback: 0 kB WbReclaimable: 0 kB WbDirtyThresh: 0 kB WbDirtied: 0 kB WbWritten: 0 kB WbWriteBandwidth: 102400 kBps b_dirty: 0 b_io: 0 b_more_io: 0 b_dirty_time: 0 state: 1 WbCgIno: 4094 WbWriteback: 54432 kB WbReclaimable: 766080 kB WbDirtyThresh: 3094760 kB WbDirtied: 1656480 kB WbWritten: 837088 kB WbWriteBandwidth: 132772 kBps b_dirty: 1 b_io: 1 b_more_io: 0 b_dirty_time: 0 state: 7 WbCgIno: 4135 WbWriteback: 15232 kB WbReclaimable: 786688 kB WbDirtyThresh: 2909984 kB WbDirtied: 1482656 kB WbWritten: 681408 kB WbWriteBandwidth: 124848 kBps b_dirty: 0 b_io: 1 b_more_io: 0 b_dirty_time: 0 state: 7 Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> --- include/linux/writeback.h | 1 + mm/backing-dev.c | 78 ++++++++++++++++++++++++++++++++++++++- mm/page-writeback.c | 19 ++++++++++ 3 files changed, 96 insertions(+), 2 deletions(-)