From nobody Fri Dec 19 17:19:13 2025 Received: from invmail4.hynix.com (exvmail4.hynix.com [166.125.252.92]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 0A35C27978F; Mon, 19 May 2025 09:18:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=166.125.252.92 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747646343; cv=none; b=UByRoWvLk3FNL1mkvQ8czrvNuRFfn/JnRpBgOg1WnTkPQOXMNqwt77fPtabPK+wCtrlr5Du8zeKvHAX2wiXvoqjdbbhnehZIYClBnYS6SvXtm9nyM5HdrWwNOjpWaHNBOOZsVVEivNmAlbLQ4xsD3SewunDJhYchBP2o91WYUPI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747646343; c=relaxed/simple; bh=xIkkCdiOJcy9hW8Y2iXba7Lek3wWMYXG6Tsggjp1lwA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=UiTr2w0vnqXS4T+fkqekX6OzD9qifsQe0F77r36Hio/DdDcWnfCJXKVpSzVLxrASINWrqhrMss3x2Ge8DYIC8ALAmjcZo84S47EYhl0AfaBnz6oMSIvYwvgRGu/zFQ7Fc6tDz0jxfZe2cKrOSjpKX3L/v3khQs+mp4Tn5B93GbA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com; spf=pass smtp.mailfrom=sk.com; arc=none smtp.client-ip=166.125.252.92 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sk.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sk.com X-AuditID: a67dfc5b-681ff7000002311f-6d-682af76fcbf6 From: Byungchul Park To: linux-kernel@vger.kernel.org Cc: kernel_team@skhynix.com, torvalds@linux-foundation.org, damien.lemoal@opensource.wdc.com, linux-ide@vger.kernel.org, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, mingo@redhat.com, peterz@infradead.org, will@kernel.org, tglx@linutronix.de, rostedt@goodmis.org, joel@joelfernandes.org, sashal@kernel.org, daniel.vetter@ffwll.ch, duyuyang@gmail.com, johannes.berg@intel.com, tj@kernel.org, tytso@mit.edu, willy@infradead.org, david@fromorbit.com, amir73il@gmail.com, gregkh@linuxfoundation.org, kernel-team@lge.com, linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@kernel.org, minchan@kernel.org, hannes@cmpxchg.org, vdavydov.dev@gmail.com, sj@kernel.org, jglisse@redhat.com, dennis@kernel.org, cl@linux.com, penberg@kernel.org, rientjes@google.com, vbabka@suse.cz, ngupta@vflare.org, linux-block@vger.kernel.org, josef@toxicpanda.com, linux-fsdevel@vger.kernel.org, jack@suse.cz, jlayton@kernel.org, dan.j.williams@intel.com, hch@infradead.org, djwong@kernel.org, dri-devel@lists.freedesktop.org, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com, harry.yoo@oracle.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, yskelg@gmail.com, yunseong.kim@ericsson.com, yeoreum.yun@arm.com, netdev@vger.kernel.org, matthew.brost@intel.com, her0gyugyu@gmail.com Subject: [PATCH v16 26/42] dept: print staged wait's stacktrace on report Date: Mon, 19 May 2025 18:18:10 +0900 Message-Id: <20250519091826.19752-27-byungchul@sk.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20250519091826.19752-1-byungchul@sk.com> References: <20250519091826.19752-1-byungchul@sk.com> X-Brightmail-Tracker: H4sIAAAAAAAAAzWSfUzMcRzHfX/PXc5+O08/DxtuDJk4U/vMMH/xs7EZ/sGGm35zt564cso0 pTtyKcnqSHI97LQ6yl2jcKR0VB6ic04qdWvNcdXk7qiO3GX++ey1z3vv1+efD4NLWsj5jDIh WVAlyOOklIgQDU0vXZ34M0KxdlgD4PNmEVBcY6Kg4041AlNdBgbulm3wwe9BMPHqDQ76gg4E pf09ONTZehFYK89S0DkwA+y+EQpaC7IpyCyvoeDttwAG3YX5GFSbd8Jn4yAB7XllGOjdFFzX Z2LB8QWDMWMVDcb0ZeCqLKIh0C+D1l4HCdauVXCtpJuCR9ZWAmz1Lgw6HxRT0GuaJKHd9oIA f+4C6LicQ8Lt4TIKvvmNOBh9IzS8azRgYDPMgVpNUHjuxx8Snuc0YnCu4i4G9o8PETzO6sPA bHJQ0OzzYGAxF+AwfqsFgSt3iAbtxTEarmfkIsjWFhKg6Y6CiV/Byze8Msi4WUvA7d8OtGUT byoxIb7ZM4LzGstJftz3nuKtfgPBt5VxfENRD81rHnfRvMF8grdURvDlj9wYXzrqI3lz1QWK N4/m07xuyI7xw69f07sW7hdtjBHilGpBtWbzYZHi86/IY4FNKYVXHVQ6cst0iGE4dj1nz0rT obAp/DRup0NMscs5p3MMD/EsdjFnyRkkdUjE4KwjnPtw4yMKBTPZ7ZxrsI0IMcEu4y6PGYmQ U8xGcw23kv85F3HVtY1TnrDguiu7eaoqYaM4e3UJEXJyrD6Msw5r8X+FedzTSieRh8QGNK0K SZQJ6ni5Mm59pCI1QZkSeSQx3oyCz2VMCxyoR6Mde5oQyyDpdHGtdaVCQsrVSanxTYhjcOks cZVlhUIijpGnnhJUiYdUJ+KEpCa0gCGkc8Xr/CdjJOxRebIQKwjHBNX/FGPC5qejK09o0IVf io0+/rx8zTr1+dJ7rp179x3cm/WmDTIPomfftV/72rVHd79MexfrWeEpKO+Jygj3Gtys7X6y d1AWrt41MbD7ZdHSyTt5WvvDDQONzmKVtK+e5KIrLJ2srCXAjM6uOW3Z+jOtv6d4x+TWM0sk em+Ks8xEFr5/1ZwvlRJJCrksAlclyf8CoBHhQ1gDAAA= X-Brightmail-Tracker: H4sIAAAAAAAAAzWSbUxTZxTHfe47ZddcK5k3srmlppmigiRUz+JGtpjo4+LbN+O+jCo3tgKt aSmKiQlIFYVBxKSAL3QVTCVtFXarUdFqhYgWYkWpVRgvSgyxAmIcrQLVrbjsy8kv55/zO1/+ HKlsphdzekOhZDJo81WMglJsXVe2yvg+Tbe6rWIpRKeOUXC2xcNAzyU3As/lUgIidzfC09g4 gtkHD0mos/UgOPdikITLnUMIfM2HGeh9OR9C0UkGArZKBsqaWhh4NBYnYKD2JAFueQsMO0cp 6D7RSEBdhIEzdWVEYrwiYNrpYsFZooaR5tMsxF9kQmAoTENHQ4AGX/8KOGUfYOCmL0BB57UR AnrbzjIw5PmHhu7O+xTEqlOhp6aKhotvGhkYizlJcEYnWXjsdxDQ6fgSWq0J69G/P9Fwr8pP wNHzfxIQ6ruB4Nax5wTInjADHdFxAryyjYSZC3cRjFRPsHDk92kWzpRWI6g8UkuBdUADsx8S nxumMqH0j1YKLn4Mo5+yscfuQbhjfJLEVu9+PBN9wmBfzEHhrkYRXz89yGLrrX4WO2QL9jan 4aabEQKfexelsew6zmD53UkWV0yECPwmGGS3f/2r4odcKV9fJJkysnMUuuEP6fviPx6orQ8z JSiSWYGSOFHIEv+aCbFzzAjfic+eTZNznCJ8K3qrRukKpOBIIZwsPm3oQ3PBQmGTODLaRc0x JajFmmlngjmOF9aI1y8U/uf8RnS3+j97khLr/sqOz6dKQSOG3HbqBFI40DwXStEbigq0+nxN ujlPV2zQH0jfbSyQUaI/zkPxmmtoqndjOxI4pPqCb/Ut1ylpbZG5uKAdiRypSuFd3mU6JZ+r LT4omYy/mSz5krkdpXKUahH/yw4pRyns0RZKeZK0TzL9nxJc0uISZKS/X2JNNt97vEF/iTbi 25p40rpByy5ejsiGzV/ZlntTr+TyeU1tszumdCst6p/XB5bVl9Pr+UOvx67Oy2Da9ua8dde7 Xqvtlfbhj6uS8ZLsterG9xMLNNuO70zh/d2x8g2n+g4Hs7LuUJ8iFPcqzbXJL5cLLVEbEQgG 71tUlFmnzUwjTWbtv94ReEw7AwAA X-CFilter-Loop: Reflected Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Currently, print nothing about what event wakes up in report. However, it makes hard to interpret dept's report. Make it print wait's stacktrace that the event wakes up. Signed-off-by: Byungchul Park --- include/linux/dept.h | 5 ++++ include/linux/sched.h | 2 ++ kernel/dependency/dept.c | 59 ++++++++++++++++++++++++++++++++++------ 3 files changed, 57 insertions(+), 9 deletions(-) diff --git a/include/linux/dept.h b/include/linux/dept.h index 236e4f06e5c8..b6dc4ff19537 100644 --- a/include/linux/dept.h +++ b/include/linux/dept.h @@ -227,6 +227,11 @@ struct dept_ecxt { */ unsigned long event_ip; struct dept_stack *event_stack; + + /* + * wait that this event ttwu + */ + struct dept_stack *ewait_stack; }; }; }; diff --git a/include/linux/sched.h b/include/linux/sched.h index 541ddacdc3d0..43927e61921b 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -865,6 +865,7 @@ struct dept_task { const char *stage_w_fn; unsigned long stage_ip; bool stage_timeout; + struct dept_stack *stage_wait_stack; arch_spinlock_t stage_lock; =20 /* @@ -906,6 +907,7 @@ struct dept_task { .stage_w_fn =3D NULL, \ .stage_ip =3D 0UL, \ .stage_timeout =3D false, \ + .stage_wait_stack =3D NULL, \ .stage_lock =3D (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED,\ .missing_ecxt =3D 0, \ .hardirqs_enabled =3D false, \ diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 79357a3a03bb..dc3effabfab4 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -523,6 +523,7 @@ static void initialize_ecxt(struct dept_ecxt *e) e->enirqf =3D 0UL; e->event_ip =3D 0UL; e->event_stack =3D NULL; + e->ewait_stack =3D NULL; } SET_CONSTRUCTOR(ecxt, initialize_ecxt); =20 @@ -578,6 +579,8 @@ static void destroy_ecxt(struct dept_ecxt *e) put_stack(e->ecxt_stack); if (e->event_stack) put_stack(e->event_stack); + if (e->ewait_stack) + put_stack(e->ewait_stack); } SET_DESTRUCTOR(ecxt, destroy_ecxt); =20 @@ -794,6 +797,11 @@ static void print_dep(struct dept_dep *d) =20 pr_warn("[E] %s(%s:%d):\n", e_fn, fc_n, fc->sub_id); print_ip_stack(e->event_ip, e->event_stack); + + if (valid_stack(e->ewait_stack)) { + pr_warn("(wait to wake up)\n"); + print_ip_stack(0, e->ewait_stack); + } } =20 if (!irqf) { @@ -807,6 +815,11 @@ static void print_dep(struct dept_dep *d) =20 pr_warn("[E] %s(%s:%d):\n", e_fn, fc_n, fc->sub_id); print_ip_stack(e->event_ip, e->event_stack); + + if (valid_stack(e->ewait_stack)) { + pr_warn("(wait to wake up)\n"); + print_ip_stack(0, e->ewait_stack); + } } } =20 @@ -1657,7 +1670,8 @@ static void add_wait(struct dept_class *c, unsigned l= ong ip, =20 static struct dept_ecxt_held *add_ecxt(struct dept_map *m, struct dept_class *c, unsigned long ip, const char *c_fn, - const char *e_fn, int sub_l) + const char *e_fn, int sub_l, + struct dept_stack *ewait_stack) { struct dept_task *dt =3D dept_task(); struct dept_ecxt_held *eh; @@ -1691,6 +1705,7 @@ static struct dept_ecxt_held *add_ecxt(struct dept_ma= p *m, e->class =3D get_class(c); e->ecxt_ip =3D ip; e->ecxt_stack =3D ip ? get_current_stack() : NULL; + e->ewait_stack =3D ewait_stack ? get_stack(ewait_stack) : NULL; e->event_fn =3D e_fn; e->ecxt_fn =3D c_fn; =20 @@ -1797,7 +1812,7 @@ static int find_hist_pos(unsigned int wg) =20 static void do_event(struct dept_map *m, struct dept_map *real_m, struct dept_class *c, unsigned int wg, unsigned long ip, - const char *e_fn) + const char *e_fn, struct dept_stack *ewait_stack) { struct dept_task *dt =3D dept_task(); struct dept_wait_hist *wh; @@ -1825,7 +1840,7 @@ static void do_event(struct dept_map *m, struct dept_= map *real_m, */ if (find_ecxt_pos(real_m, c, false) !=3D -1) return; - eh =3D add_ecxt(m, c, 0UL, NULL, e_fn, 0); + eh =3D add_ecxt(m, c, 0UL, NULL, e_fn, 0, ewait_stack); =20 if (!eh) return; @@ -2360,7 +2375,8 @@ static void __dept_wait(struct dept_map *m, unsigned = long w_f, */ static void __dept_event(struct dept_map *m, struct dept_map *real_m, unsigned long e_f, unsigned long ip, const char *e_fn, - bool sched_map, unsigned int wg) + bool sched_map, unsigned int wg, + struct dept_stack *ewait_stack) { struct dept_class *c; struct dept_key *k; @@ -2382,7 +2398,7 @@ static void __dept_event(struct dept_map *m, struct d= ept_map *real_m, c =3D check_new_class(&m->map_key, k, sub_id(m, e), m->name, sched_map); =20 if (c) - do_event(m, real_m, c, wg, ip, e_fn); + do_event(m, real_m, c, wg, ip, e_fn, ewait_stack); } =20 void dept_wait(struct dept_map *m, unsigned long w_f, @@ -2498,6 +2514,9 @@ static void __dept_clean_stage(struct dept_task *dt) dt->stage_w_fn =3D NULL; dt->stage_ip =3D 0UL; dt->stage_timeout =3D false; + if (dt->stage_wait_stack) + put_stack(dt->stage_wait_stack); + dt->stage_wait_stack =3D NULL; } =20 void dept_clean_stage(void) @@ -2561,6 +2580,14 @@ void dept_request_event_wait_commit(void) =20 wg =3D next_wgen(); WRITE_ONCE(dt->stage_m.wgen, wg); + + /* + * __schedule() can be hit multiple times between + * dept_stage_wait() and dept_clean_stage(). In that case, + * keep the first stacktrace only. That's enough. + */ + if (!dt->stage_wait_stack) + dt->stage_wait_stack =3D get_current_stack(); arch_spin_unlock(&dt->stage_lock); =20 __dept_wait(&dt->stage_m, 1UL, ip, w_fn, 0, true, sched_map, timeout); @@ -2579,6 +2606,7 @@ void dept_ttwu_stage_wait(struct task_struct *request= or, unsigned long ip) struct dept_map m; struct dept_map *real_m; bool sched_map; + struct dept_stack *ewait_stack; =20 if (unlikely(!dept_working())) return; @@ -2597,6 +2625,10 @@ void dept_ttwu_stage_wait(struct task_struct *reques= tor, unsigned long ip) m =3D dt_req->stage_m; sched_map =3D dt_req->stage_sched_map; real_m =3D dt_req->stage_real_m; + ewait_stack =3D dt_req->stage_wait_stack; + if (ewait_stack) + get_stack(ewait_stack); + __dept_clean_stage(dt_req); arch_spin_unlock(&dt_req->stage_lock); =20 @@ -2607,8 +2639,12 @@ void dept_ttwu_stage_wait(struct task_struct *reques= tor, unsigned long ip) if (!m.keys) goto exit; =20 - __dept_event(&m, real_m, 1UL, ip, "try_to_wake_up", sched_map, m.wgen); + __dept_event(&m, real_m, 1UL, ip, "try_to_wake_up", sched_map, + m.wgen, ewait_stack); exit: + if (ewait_stack) + put_stack(ewait_stack); + dept_exit(flags); } =20 @@ -2688,7 +2724,7 @@ void dept_map_ecxt_modify(struct dept_map *m, unsigne= d long e_f, k =3D m->keys ?: &m->map_key; c =3D check_new_class(&m->map_key, k, sub_id(m, new_e), m->name, false); =20 - if (c && add_ecxt(m, c, new_ip, new_c_fn, new_e_fn, new_sub_l)) + if (c && add_ecxt(m, c, new_ip, new_c_fn, new_e_fn, new_sub_l, NULL)) goto exit; =20 /* @@ -2740,7 +2776,7 @@ void dept_ecxt_enter(struct dept_map *m, unsigned lon= g e_f, unsigned long ip, k =3D m->keys ?: &m->map_key; c =3D check_new_class(&m->map_key, k, sub_id(m, e), m->name, false); =20 - if (c && add_ecxt(m, c, ip, c_fn, e_fn, sub_l)) + if (c && add_ecxt(m, c, ip, c_fn, e_fn, sub_l, NULL)) goto exit; missing_ecxt: dt->missing_ecxt++; @@ -2840,7 +2876,7 @@ void dept_event(struct dept_map *m, unsigned long e_f, =20 flags =3D dept_enter(); =20 - __dept_event(m, m, e_f, ip, e_fn, false, READ_ONCE(*wg_p)); + __dept_event(m, m, e_f, ip, e_fn, false, READ_ONCE(*wg_p), NULL); =20 /* * Keep the map diabled until the next sleep. @@ -2912,6 +2948,11 @@ void dept_task_exit(struct task_struct *t) dt->stack =3D NULL; } =20 + if (dt->stage_wait_stack) { + put_stack(dt->stage_wait_stack); + dt->stage_wait_stack =3D NULL; + } + for (i =3D 0; i < dt->ecxt_held_pos; i++) { if (dt->ecxt_held[i].class) { put_class(dt->ecxt_held[i].class); --=20 2.17.1