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WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20240423004430.140320-1-sj@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-CM-TRANSID:cCh0CgDn_AXgDidm4QTWKg--.37601S2 X-Coremail-Antispam: 1UD129KBjvJXoW3GF15CFW3XFWUGrWUGr4kZwb_yoWxWF1fpF Z8J3W5Kr4UXryxG3ZI9a9Fgry5tw40qry7XF97Aay8tr1vvr93WFyfurWFyryUAFZ3AFW3 Aa1YvF97G3yqy3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvab4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUGVWUXwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mxk0xIA0c2IE e2xFo4CEbIxvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q 6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWrJr0_WFyUJwCI42IY6I8E87Iv 67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyT uYvjxUOyCJDUUUU X-CM-SenderInfo: 5vklyvpphqwq5kxd4v5lfo033gof0z/ X-Rspamd-Queue-Id: 7CF22C000D X-Stat-Signature: kmxm69e4qw6mkf83jrxkiapp8sfotceb X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1713835751-623302 X-HE-Meta: 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 hDDkwuwL vEecYe1//ftvGYTkmHfKBwr5bn6Cupu81IPmDd9Ktkp52KQ76gS125H34uMAuSVspaSM114CXSFRD0LlH08UGDpd+tqVrx3uSz54CENuChu81lRn6XKk30z21kEwNpnvsMIq9GdilbkDjDoynGqm/P2oA4T4r+FW9AUDlVIraY4k1dvhc5IfOy8Guqe2Qn2LFS4NU75dzCnKuaElZNrWVxSBVQA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello on 4/23/2024 8:44 AM, SeongJae Park wrote: > Hi Kemeng, > > On Tue, 23 Apr 2024 00:48:06 +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 >> --- >> 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 > > [...] >