From: Guo Mengqi guomengqi3@huawei.com
hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5ODCT CVE: NA
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When there are a large number of groups in the system, or with a large number of processes in each group, "cat /proc/sharepool/proc_stat" will encounter softlockup before all prints finished. This is because there are too many loops in the callback function. Remove one of the loops to reduce time cost and add a cond_resched() to avoid this.
root@buildroot:~/install# cat /proc/sharepool/proc_stat [ 1250.647469] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cat:309] [ 1250.648610] Modules linked in: sharepool_dev(OE) [ 1250.650795] CPU: 0 PID: 309 Comm: cat Tainted: G OE 5.10.0+ #43 [ 1250.651216] Hardware name: linux,dummy-virt (DT) [ 1250.651721] pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--) [ 1250.652426] pc : get_process_sp_res+0x40/0x90 [ 1250.652747] lr : proc_usage_by_group+0x158/0x218 ... [ 1250.657903] Call trace: [ 1250.658376] get_process_sp_res+0x40/0x90 [ 1250.658602] proc_usage_by_group+0x158/0x218 [ 1250.658838] idr_for_each+0x6c/0xf0 [ 1250.659027] proc_group_usage_show+0x104/0x120 [ 1250.659263] seq_read_iter+0xe0/0x498 [ 1250.659462] proc_reg_read_iter+0xa8/0xe0 [ 1250.659660] generic_file_splice_read+0xf0/0x1b0 [ 1250.659865] do_splice_to+0x7c/0xd0 [ 1250.660029] splice_direct_to_actor+0xe0/0x2a8 [ 1250.660353] do_splice_direct+0xa4/0xf8 [ 1250.660902] do_sendfile+0x1bc/0x420 [ 1250.661079] __arm64_sys_sendfile64+0x170/0x178 [ 1250.661298] el0_svc_common.constprop.0+0x88/0x268 [ 1250.661505] do_el0_svc+0x34/0xb8 [ 1250.661686] el0_svc+0x1c/0x28 [ 1250.661836] el0_sync_handler+0x8c/0xb0 [ 1250.662033] el0_sync+0x168/0x180
Signed-off-by: Guo Mengqi guomengqi3@huawei.com --- mm/share_pool.c | 21 +++++++-------------- 1 file changed, 7 insertions(+), 14 deletions(-)
diff --git a/mm/share_pool.c b/mm/share_pool.c index 963cac4734ac..4a6933a16551 100644 --- a/mm/share_pool.c +++ b/mm/share_pool.c @@ -4023,7 +4023,6 @@ static int proc_usage_by_group(int id, void *p, void *data) struct sp_group_master *master; int tgid; unsigned long anon, file, shmem, total_rss; - long sp_res, sp_res_nsize, non_sp_res, non_sp_shm;
down_read(&spg->rw_lock); list_for_each_entry(spg_node, &spg->procs, proc_node) { @@ -4038,26 +4037,20 @@ static int proc_usage_by_group(int id, void *p, void *data) tgid = master->instat.tgid;
get_mm_rss_info(mm, &anon, &file, &shmem, &total_rss); - get_process_sp_res(master, &sp_res, &sp_res_nsize); - get_process_non_sp_res(total_rss, shmem, sp_res_nsize, - &non_sp_res, &non_sp_shm);
seq_printf(seq, "%-8d ", tgid); - if (id == 0) - seq_printf(seq, "%-8c ", '-'); - else - seq_printf(seq, "%-8d ", id); - seq_printf(seq, "%-9ld %-9ld %-9ld %-10ld %-10ld %-8ld %-7ld %-7ld %-10ld ", + seq_printf(seq, "%-8d ", id); + seq_printf(seq, "%-9ld %-9ld %-9ld %-8ld %-7ld %-7ld ", get_spg_proc_alloc(spg_node), get_spg_proc_k2u(spg_node), get_sp_res_by_spg_proc(spg_node), - sp_res, non_sp_res, page2kb(mm->total_vm), page2kb(total_rss), - page2kb(shmem), non_sp_shm); + page2kb(shmem)); print_process_prot(seq, spg_node->prot); seq_putc(seq, '\n'); } up_read(&spg->rw_lock); + cond_resched();
return 0; } @@ -4068,9 +4061,9 @@ static int proc_group_usage_show(struct seq_file *seq, void *offset) spa_overview_show(seq);
/* print the file header */ - seq_printf(seq, "%-8s %-8s %-9s %-9s %-9s %-10s %-10s %-8s %-7s %-7s %-10s %-4s\n", - "PID", "Group_ID", "SP_ALLOC", "SP_K2U", "SP_RES", "SP_RES_T", - "Non-SP_RES", "VIRT", "RES", "Shm", "Non-SP_Shm", "PROT"); + seq_printf(seq, "%-8s %-8s %-9s %-9s %-9s %-8s %-7s %-7s %-4s\n", + "PID", "Group_ID", "SP_ALLOC", "SP_K2U", "SP_RES", + "VIRT", "RES", "Shm", "PROT"); /* print kthread buff_module_guard_work */ seq_printf(seq, "%-8s %-8s %-9lld %-9lld\n", "guard", "-",