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X-AuditID: a67dfc5b-d6dff70000001748-cb-64e2ded6eaec 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, viro@zeniv.linux.org.uk, 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, 42.hyeyoo@gmail.com, chris.p.wilson@intel.com, gwan-gyeong.mun@intel.com, max.byungchul.park@gmail.com, boqun.feng@gmail.com, longman@redhat.com, hdanton@sina.com, her0gyugyu@gmail.com Subject: [RESEND PATCH v10 14/25] dept: Add a mechanism to refill the internal memory pools on running out Date: Mon, 21 Aug 2023 12:46:26 +0900 Message-Id: <20230821034637.34630-15-byungchul@sk.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20230821034637.34630-1-byungchul@sk.com> References: <20230821034637.34630-1-byungchul@sk.com> X-Brightmail-Tracker: H4sIAAAAAAAAAzWSf0yMcRzHfb/PzzvOnp3Go2xyG1omEvYZZtjwbH6MnT9MG27umY46diWy mVBKicrqqMMpzqlIFxuu7FyUQsW1SqrpOqrph+KOq0gX/vnstfd779dfH5aQWyl/VqONEXVa 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H4sIAAAAAAAAAzWSXUxTZxzGfd9zzntOq51nlbkTYEGbEBKMHzgx/8XF4IXxZGxmZhdGjUK1 J1KBQlqEIllA+ZiCGDFDsFSHqKVSNlwhhgE1HSha/IAJYUCgscUoBJTBaKXCRKrZzZNfnif5 XT0cpTQzoZxWlyHpdeoUFZHT8t3b8tf3u72aTTfDoOzsJvDNnqbB3FBPoOc3G4L6ppMYxu/t gr/9kwjmH3dTUFHeg+CqZ4SCpk43Aof1FIHe559An2+KgKu8hED+tQYCf00sYBi+eAGDzf4d PDxfg8EZeElDxTiBqop8vBRjGAKWOhYseZHgtZpYWPDEgMvdz0DHZRcDjqF1cOnKMIE2h4uG zmYvht4WMwF3/SIDDzsf0NBTVsrAr69rCEz4LRRYfFMsPHVWY7hVsGQr+vcdA/dLnRiKrv+O oW+wFcGd088w2Ov7CXT4JjE02sspeFt7D4H33CsWCs8GWKg6eQ5BSeFFGrr/u89AwXAszM+Z Sdw2sWNyihILGrNEh7+aFrtqBPEP0wgrFtwZYsVq+3Gx0RotXmsbx+LVGR8j2uvOENE+c4EV i1/1YfH1kyes+KBynhaf91Xg78P3y7/WSCnaTEm/cXuiPMlc2IXT6+KMo4NOJg+VfFmMZJzA bxF6x0xUkAkfJQwMBD5wCL9GaCx9wRQjOUfxPy0XrP88JsFhFX9MGPqzHAeZ5iOFl4FuOsgK fqvQartJPkojBNst5weRbKm3t7agICv5WGHaM0qfR/JqtKwOhWh1malqbUrsBkNyUrZOa9xw JC3VjpY+Y/lxoawZzfbuakc8h1QrFInhXo2SUWcaslPbkcBRqhBF2BuPRqnQqLNPSPq0BP3x FMnQjsI4WvW54pu9UqKSP6rOkJIlKV3S/79iThaah3ZPa/ZU1hyKfxRTy285PK5zb/600mXN XJt1uOkpaTN9u8Mvywhdkx7ePLb6gCfHeHTQWBSfOzSTsM+yKnlHl61wcVnOF4Z3RsdoXOy6 Ux1zO9P1zRFZEBG5+Eva+ly/7LOD3FcjZ0bvTl/anPvDQJvJlf1zrapFqHqxMgpC42+E3VbR hiR1TDSlN6jfA2rEmL4vAwAA X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Dept engine works in a constrained environment. For example, Dept cannot make use of dynamic allocation e.g. kmalloc(). So Dept has been using static pools to keep memory chunks Dept uses. However, Dept would barely work once any of the pools gets run out. So implemented a mechanism for the refill on the lack by any chance, using irq work and workqueue that fits on the contrained environment. Signed-off-by: Byungchul Park --- include/linux/dept.h | 19 ++++-- kernel/dependency/dept.c | 104 +++++++++++++++++++++++++++----- kernel/dependency/dept_object.h | 10 +-- kernel/dependency/dept_proc.c | 8 +-- 4 files changed, 112 insertions(+), 29 deletions(-) diff --git a/include/linux/dept.h b/include/linux/dept.h index d9ca9dd50219..583e8fe2dd7b 100644 --- a/include/linux/dept.h +++ b/include/linux/dept.h @@ -336,9 +336,19 @@ struct dept_pool { size_t obj_sz; /* - * the number of the static array + * the remaining number of the object in spool */ - atomic_t obj_nr; + int obj_nr; + + /* + * the number of the object in spool + */ + int tot_nr; + + /* + * accumulated amount of memory used by the object in byte + */ + atomic_t acc_sz; /* * offset of ->pool_node @@ -348,9 +358,10 @@ struct dept_pool { /* * pointer to the pool */ - void *spool; + void *spool; /* static pool */ + void *rpool; /* reserved pool */ struct llist_head boot_pool; - struct llist_head __percpu *lpool; + struct llist_head __percpu *lpool; /* local pool */ }; struct dept_ecxt_held { diff --git a/kernel/dependency/dept.c b/kernel/dependency/dept.c index 6cf17f206b78..8454f0a14d67 100644 --- a/kernel/dependency/dept.c +++ b/kernel/dependency/dept.c @@ -74,6 +74,9 @@ #include #include #include +#include +#include +#include #include "dept_internal.h" static int dept_stop; @@ -122,10 +125,12 @@ static int dept_per_cpu_ready; WARN(1, "DEPT_STOP: " s); \ }) -#define DEPT_INFO_ONCE(s...) pr_warn_once("DEPT_INFO_ONCE: " s) +#define DEPT_INFO_ONCE(s...) pr_warn_once("DEPT_INFO_ONCE: " s) +#define DEPT_INFO(s...) pr_warn("DEPT_INFO: " s) static arch_spinlock_t dept_spin = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; static arch_spinlock_t stage_spin = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; +static arch_spinlock_t dept_pool_spin = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; /* * DEPT internal engine should be careful in using outside functions @@ -264,6 +269,7 @@ static inline bool valid_key(struct dept_key *k) #define OBJECT(id, nr) \ static struct dept_##id spool_##id[nr]; \ +static struct dept_##id rpool_##id[nr]; \ static DEFINE_PER_CPU(struct llist_head, lpool_##id); #include "dept_object.h" #undef OBJECT @@ -272,14 +278,70 @@ struct dept_pool dept_pool[OBJECT_NR] = { #define OBJECT(id, nr) { \ .name = #id, \ .obj_sz = sizeof(struct dept_##id), \ - .obj_nr = ATOMIC_INIT(nr), \ + .obj_nr = nr, \ + .tot_nr = nr, \ + .acc_sz = ATOMIC_INIT(sizeof(spool_##id) + sizeof(rpool_##id)), \ .node_off = offsetof(struct dept_##id, pool_node), \ .spool = spool_##id, \ + .rpool = rpool_##id, \ .lpool = &lpool_##id, }, #include "dept_object.h" #undef OBJECT }; +static void dept_wq_work_fn(struct work_struct *work) +{ + int i; + + for (i = 0; i < OBJECT_NR; i++) { + struct dept_pool *p = dept_pool + i; + int sz = p->tot_nr * p->obj_sz; + void *rpool; + bool need; + + arch_spin_lock(&dept_pool_spin); + need = !p->rpool; + arch_spin_unlock(&dept_pool_spin); + + if (!need) + continue; + + rpool = vmalloc(sz); + + if (!rpool) { + DEPT_STOP("Failed to extend internal resources.\n"); + break; + } + + arch_spin_lock(&dept_pool_spin); + if (!p->rpool) { + p->rpool = rpool; + rpool = NULL; + atomic_add(sz, &p->acc_sz); + } + arch_spin_unlock(&dept_pool_spin); + + if (rpool) + vfree(rpool); + else + DEPT_INFO("Dept object(%s) just got refilled successfully.\n", p->name); + } +} + +static DECLARE_WORK(dept_wq_work, dept_wq_work_fn); + +static void dept_irq_work_fn(struct irq_work *w) +{ + schedule_work(&dept_wq_work); +} + +static DEFINE_IRQ_WORK(dept_irq_work, dept_irq_work_fn); + +static void request_rpool_refill(void) +{ + irq_work_queue(&dept_irq_work); +} + /* * Can use llist no matter whether CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG is * enabled or not because NMI and other contexts in the same CPU never @@ -315,19 +377,31 @@ static void *from_pool(enum object_t t) /* * Try static pool. */ - if (atomic_read(&p->obj_nr) > 0) { - int idx = atomic_dec_return(&p->obj_nr); + arch_spin_lock(&dept_pool_spin); + + if (!p->obj_nr) { + p->spool = p->rpool; + p->obj_nr = p->rpool ? p->tot_nr : 0; + p->rpool = NULL; + request_rpool_refill(); + } + + if (p->obj_nr) { + void *ret; + + p->obj_nr--; + ret = p->spool + (p->obj_nr * p->obj_sz); + arch_spin_unlock(&dept_pool_spin); - if (idx >= 0) - return p->spool + (idx * p->obj_sz); + return ret; } + arch_spin_unlock(&dept_pool_spin); - DEPT_INFO_ONCE("---------------------------------------------\n" - " Some of Dept internal resources are run out.\n" - " Dept might still work if the resources get freed.\n" - " However, the chances are Dept will suffer from\n" - " the lack from now. Needs to extend the internal\n" - " resource pools. Ask max.byungchul.park@gmail.com\n"); + DEPT_INFO("------------------------------------------\n" + " Dept object(%s) is run out.\n" + " Dept is trying to refill the object.\n" + " Nevertheless, if it fails, Dept will stop.\n", + p->name); return NULL; } @@ -3000,8 +3074,8 @@ void __init dept_init(void) pr_info("... DEPT_MAX_ECXT_HELD : %d\n", DEPT_MAX_ECXT_HELD); pr_info("... DEPT_MAX_SUBCLASSES : %d\n", DEPT_MAX_SUBCLASSES); #define OBJECT(id, nr) \ - pr_info("... memory used by %s: %zu KB\n", \ - #id, B2KB(sizeof(struct dept_##id) * nr)); + pr_info("... memory initially used by %s: %zu KB\n", \ + #id, B2KB(sizeof(spool_##id) + sizeof(rpool_##id))); #include "dept_object.h" #undef OBJECT #define HASH(id, bits) \ @@ -3009,6 +3083,6 @@ void __init dept_init(void) #id, B2KB(sizeof(struct hlist_head) * (1 << (bits)))); #include "dept_hash.h" #undef HASH - pr_info("... total memory used by objects and hashs: %zu KB\n", B2KB(mem_total)); + pr_info("... total memory initially used by objects and hashs: %zu KB\n", B2KB(mem_total)); pr_info("... per task memory footprint: %zu bytes\n", sizeof(struct dept_task)); } diff --git a/kernel/dependency/dept_object.h b/kernel/dependency/dept_object.h index 0b7eb16fe9fb..4f936adfa8ee 100644 --- a/kernel/dependency/dept_object.h +++ b/kernel/dependency/dept_object.h @@ -6,8 +6,8 @@ * nr: # of the object that should be kept in the pool. */ -OBJECT(dep, 1024 * 8) -OBJECT(class, 1024 * 8) -OBJECT(stack, 1024 * 32) -OBJECT(ecxt, 1024 * 16) -OBJECT(wait, 1024 * 32) +OBJECT(dep, 1024 * 4 * 2) +OBJECT(class, 1024 * 4) +OBJECT(stack, 1024 * 4 * 8) +OBJECT(ecxt, 1024 * 4 * 2) +OBJECT(wait, 1024 * 4 * 4) diff --git a/kernel/dependency/dept_proc.c b/kernel/dependency/dept_proc.c index 7d61dfbc5865..f07a512b203f 100644 --- a/kernel/dependency/dept_proc.c +++ b/kernel/dependency/dept_proc.c @@ -73,12 +73,10 @@ static int dept_stats_show(struct seq_file *m, void *v) { int r; - seq_puts(m, "Availability in the static pools:\n\n"); + seq_puts(m, "Accumulated amount of memory used by pools:\n\n"); #define OBJECT(id, nr) \ - r = atomic_read(&dept_pool[OBJECT_##id].obj_nr); \ - if (r < 0) \ - r = 0; \ - seq_printf(m, "%s\t%d/%d(%d%%)\n", #id, r, nr, (r * 100) / (nr)); + r = atomic_read(&dept_pool[OBJECT_##id].acc_sz); \ + seq_printf(m, "%s\t%d KB\n", #id, r / 1024); #include "dept_object.h" #undef OBJECT