Please ignore this patch! Thanks and regards, Mohammed Faiyaz.
On 4/6/2021 5:55 PM, Faiyaz Mohammed wrote: > alloc_calls and free_calls implementation in sysfs have two issues, > one is PAGE_SIZE limitiation of sysfs and other is it does not adhere > to "one value per file" rule. > > To overcome this issues, move the alloc_calls and free_calls implemeation > to debugfs. > > Signed-off-by: Faiyaz Mohammed <[email protected]> > --- > mm/slub.c | 518 > ++++++++++++++++++++++++++++++++++---------------------------- > 1 file changed, 286 insertions(+), 232 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > index 3021ce9..4d20ee0 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -36,6 +36,7 @@ > #include <linux/memcontrol.h> > #include <linux/random.h> > > +#include <linux/debugfs.h> > #include <trace/events/kmem.h> > > #include "internal.h" > @@ -225,6 +226,12 @@ static inline int sysfs_slab_alias(struct kmem_cache *s, > const char *p) > { return 0; } > #endif > > +#ifdef CONFIG_DEBUG_FS > +static void debugfs_slab_add(struct kmem_cache *); > +#else > +static inline void debugfs_slab_add(struct kmem_cache *) { } > +#endif > + > static inline void stat(const struct kmem_cache *s, enum stat_item si) > { > #ifdef CONFIG_SLUB_STATS > @@ -4542,6 +4549,8 @@ int __kmem_cache_create(struct kmem_cache *s, > slab_flags_t flags) > if (err) > __kmem_cache_release(s); > > + debugfs_slab_add(s); > + > return err; > } > > @@ -4682,221 +4691,6 @@ static long validate_slab_cache(struct kmem_cache *s) > > return count; > } > -/* > - * Generate lists of code addresses where slabcache objects are allocated > - * and freed. > - */ > - > -struct location { > - unsigned long count; > - unsigned long addr; > - long long sum_time; > - long min_time; > - long max_time; > - long min_pid; > - long max_pid; > - DECLARE_BITMAP(cpus, NR_CPUS); > - nodemask_t nodes; > -}; > - > -struct loc_track { > - unsigned long max; > - unsigned long count; > - struct location *loc; > -}; > - > -static void free_loc_track(struct loc_track *t) > -{ > - if (t->max) > - free_pages((unsigned long)t->loc, > - get_order(sizeof(struct location) * t->max)); > -} > - > -static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t > flags) > -{ > - struct location *l; > - int order; > - > - order = get_order(sizeof(struct location) * max); > - > - l = (void *)__get_free_pages(flags, order); > - if (!l) > - return 0; > - > - if (t->count) { > - memcpy(l, t->loc, sizeof(struct location) * t->count); > - free_loc_track(t); > - } > - t->max = max; > - t->loc = l; > - return 1; > -} > - > -static int add_location(struct loc_track *t, struct kmem_cache *s, > - const struct track *track) > -{ > - long start, end, pos; > - struct location *l; > - unsigned long caddr; > - unsigned long age = jiffies - track->when; > - > - start = -1; > - end = t->count; > - > - for ( ; ; ) { > - pos = start + (end - start + 1) / 2; > - > - /* > - * There is nothing at "end". If we end up there > - * we need to add something to before end. > - */ > - if (pos == end) > - break; > - > - caddr = t->loc[pos].addr; > - if (track->addr == caddr) { > - > - l = &t->loc[pos]; > - l->count++; > - if (track->when) { > - l->sum_time += age; > - if (age < l->min_time) > - l->min_time = age; > - if (age > l->max_time) > - l->max_time = age; > - > - if (track->pid < l->min_pid) > - l->min_pid = track->pid; > - if (track->pid > l->max_pid) > - l->max_pid = track->pid; > - > - cpumask_set_cpu(track->cpu, > - to_cpumask(l->cpus)); > - } > - node_set(page_to_nid(virt_to_page(track)), l->nodes); > - return 1; > - } > - > - if (track->addr < caddr) > - end = pos; > - else > - start = pos; > - } > - > - /* > - * Not found. Insert new tracking element. > - */ > - if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) > - return 0; > - > - l = t->loc + pos; > - if (pos < t->count) > - memmove(l + 1, l, > - (t->count - pos) * sizeof(struct location)); > - t->count++; > - l->count = 1; > - l->addr = track->addr; > - l->sum_time = age; > - l->min_time = age; > - l->max_time = age; > - l->min_pid = track->pid; > - l->max_pid = track->pid; > - cpumask_clear(to_cpumask(l->cpus)); > - cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); > - nodes_clear(l->nodes); > - node_set(page_to_nid(virt_to_page(track)), l->nodes); > - return 1; > -} > - > -static void process_slab(struct loc_track *t, struct kmem_cache *s, > - struct page *page, enum track_item alloc) > -{ > - void *addr = page_address(page); > - void *p; > - unsigned long *map; > - > - map = get_map(s, page); > - for_each_object(p, s, addr, page->objects) > - if (!test_bit(__obj_to_index(s, addr, p), map)) > - add_location(t, s, get_track(s, p, alloc)); > - put_map(map); > -} > - > -static int list_locations(struct kmem_cache *s, char *buf, > - enum track_item alloc) > -{ > - int len = 0; > - unsigned long i; > - struct loc_track t = { 0, 0, NULL }; > - int node; > - struct kmem_cache_node *n; > - > - if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), > - GFP_KERNEL)) { > - return sysfs_emit(buf, "Out of memory\n"); > - } > - /* Push back cpu slabs */ > - flush_all(s); > - > - for_each_kmem_cache_node(s, node, n) { > - unsigned long flags; > - struct page *page; > - > - if (!atomic_long_read(&n->nr_slabs)) > - continue; > - > - spin_lock_irqsave(&n->list_lock, flags); > - list_for_each_entry(page, &n->partial, slab_list) > - process_slab(&t, s, page, alloc); > - list_for_each_entry(page, &n->full, slab_list) > - process_slab(&t, s, page, alloc); > - spin_unlock_irqrestore(&n->list_lock, flags); > - } > - > - for (i = 0; i < t.count; i++) { > - struct location *l = &t.loc[i]; > - > - len += sysfs_emit_at(buf, len, "%7ld ", l->count); > - > - if (l->addr) > - len += sysfs_emit_at(buf, len, "%pS", (void *)l->addr); > - else > - len += sysfs_emit_at(buf, len, "<not-available>"); > - > - if (l->sum_time != l->min_time) > - len += sysfs_emit_at(buf, len, " age=%ld/%ld/%ld", > - l->min_time, > - (long)div_u64(l->sum_time, > - l->count), > - l->max_time); > - else > - len += sysfs_emit_at(buf, len, " age=%ld", l->min_time); > - > - if (l->min_pid != l->max_pid) > - len += sysfs_emit_at(buf, len, " pid=%ld-%ld", > - l->min_pid, l->max_pid); > - else > - len += sysfs_emit_at(buf, len, " pid=%ld", > - l->min_pid); > - > - if (num_online_cpus() > 1 && > - !cpumask_empty(to_cpumask(l->cpus))) > - len += sysfs_emit_at(buf, len, " cpus=%*pbl", > - > cpumask_pr_args(to_cpumask(l->cpus))); > - > - if (nr_online_nodes > 1 && !nodes_empty(l->nodes)) > - len += sysfs_emit_at(buf, len, " nodes=%*pbl", > - nodemask_pr_args(&l->nodes)); > - > - len += sysfs_emit_at(buf, len, "\n"); > - } > - > - free_loc_track(&t); > - if (!t.count) > - len += sysfs_emit_at(buf, len, "No data\n"); > - > - return len; > -} > #endif /* CONFIG_SLUB_DEBUG */ > > #ifdef SLUB_RESILIENCY_TEST > @@ -5346,21 +5140,6 @@ static ssize_t validate_store(struct kmem_cache *s, > } > SLAB_ATTR(validate); > > -static ssize_t alloc_calls_show(struct kmem_cache *s, char *buf) > -{ > - if (!(s->flags & SLAB_STORE_USER)) > - return -ENOSYS; > - return list_locations(s, buf, TRACK_ALLOC); > -} > -SLAB_ATTR_RO(alloc_calls); > - > -static ssize_t free_calls_show(struct kmem_cache *s, char *buf) > -{ > - if (!(s->flags & SLAB_STORE_USER)) > - return -ENOSYS; > - return list_locations(s, buf, TRACK_FREE); > -} > -SLAB_ATTR_RO(free_calls); > #endif /* CONFIG_SLUB_DEBUG */ > > #ifdef CONFIG_FAILSLAB > @@ -5524,8 +5303,6 @@ static struct attribute *slab_attrs[] = { > &poison_attr.attr, > &store_user_attr.attr, > &validate_attr.attr, > - &alloc_calls_attr.attr, > - &free_calls_attr.attr, > #endif > #ifdef CONFIG_ZONE_DMA > &cache_dma_attr.attr, > @@ -5814,6 +5591,283 @@ static int __init slab_sysfs_init(void) > __initcall(slab_sysfs_init); > #endif /* CONFIG_SYSFS */ > > +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) > +/* > + * Generate lists of code addresses where slabcache objects are allocated > + * and freed. > + */ > + > +struct location { > + unsigned long count; > + unsigned long addr; > + long long sum_time; > + long min_time; > + long max_time; > + long min_pid; > + long max_pid; > + DECLARE_BITMAP(cpus, NR_CPUS); > + nodemask_t nodes; > +}; > + > +struct loc_track { > + unsigned long max; > + unsigned long count; > + struct location *loc; > +}; > + > +static struct dentry *slab_debugfs_root; > + > +static struct dentry *slab_debugfs_cache; > + > +static void free_loc_track(struct loc_track *t) > +{ > + if (t->max) > + free_pages((unsigned long)t->loc, > + get_order(sizeof(struct location) * t->max)); > +} > + > +static int alloc_loc_track(struct loc_track *t, unsigned long max, gfp_t > flags) > +{ > + struct location *l; > + int order; > + > + order = get_order(sizeof(struct location) * max); > + > + l = (void *)__get_free_pages(flags, order); > + if (!l) > + return 0; > + > + if (t->count) { > + memcpy(l, t->loc, sizeof(struct location) * t->count); > + free_loc_track(t); > + } > + t->max = max; > + t->loc = l; > + return 1; > +} > + > +static int add_location(struct loc_track *t, struct kmem_cache *s, > + const struct track *track) > +{ > + long start, end, pos; > + struct location *l; > + unsigned long caddr; > + unsigned long age = jiffies - track->when; > + > + start = -1; > + end = t->count; > + > + for ( ; ; ) { > + pos = start + (end - start + 1) / 2; > + > + /* > + * There is nothing at "end". If we end up there > + * we need to add something to before end. > + */ > + if (pos == end) > + break; > + > + caddr = t->loc[pos].addr; > + if (track->addr == caddr) { > + > + l = &t->loc[pos]; > + l->count++; > + if (track->when) { > + l->sum_time += age; > + if (age < l->min_time) > + l->min_time = age; > + if (age > l->max_time) > + l->max_time = age; > + > + if (track->pid < l->min_pid) > + l->min_pid = track->pid; > + if (track->pid > l->max_pid) > + l->max_pid = track->pid; > + > + cpumask_set_cpu(track->cpu, > + to_cpumask(l->cpus)); > + } > + node_set(page_to_nid(virt_to_page(track)), l->nodes); > + return 1; > + } > + > + if (track->addr < caddr) > + end = pos; > + else > + start = pos; > + } > + > + /* > + * Not found. Insert new tracking element. > + */ > + if (t->count >= t->max && !alloc_loc_track(t, 2 * t->max, GFP_ATOMIC)) > + return 0; > + > + l = t->loc + pos; > + if (pos < t->count) > + memmove(l + 1, l, > + (t->count - pos) * sizeof(struct location)); > + t->count++; > + l->count = 1; > + l->addr = track->addr; > + l->sum_time = age; > + l->min_time = age; > + l->max_time = age; > + l->min_pid = track->pid; > + l->max_pid = track->pid; > + cpumask_clear(to_cpumask(l->cpus)); > + cpumask_set_cpu(track->cpu, to_cpumask(l->cpus)); > + nodes_clear(l->nodes); > + node_set(page_to_nid(virt_to_page(track)), l->nodes); > + return 1; > +} > + > +static void process_slab(struct loc_track *t, struct kmem_cache *s, > + struct page *page, enum track_item alloc) > +{ > + void *addr = page_address(page); > + void *p; > + unsigned long *map; > + > + map = get_map(s, page); > + for_each_object(p, s, addr, page->objects) > + if (!test_bit(__obj_to_index(s, addr, p), map)) > + add_location(t, s, get_track(s, p, alloc)); > + put_map(map); > +} > + > +static int list_locations(struct seq_file *seq, struct kmem_cache *s, > + enum track_item alloc) > +{ > + unsigned long i; > + struct loc_track t = { 0, 0, NULL }; > + int node; > + struct kmem_cache_node *n; > + > + if (!alloc_loc_track(&t, PAGE_SIZE / sizeof(struct location), > + GFP_KERNEL)) { > + seq_puts(seq, "Out of memory\n"); > + return -ENOMEM; > + } > + /* Push back cpu slabs */ > + flush_all(s); > + > + for_each_kmem_cache_node(s, node, n) { > + unsigned long flags; > + struct page *page; > + > + if (!atomic_long_read(&n->nr_slabs)) > + continue; > + > + spin_lock_irqsave(&n->list_lock, flags); > + list_for_each_entry(page, &n->partial, slab_list) > + process_slab(&t, s, page, alloc); > + list_for_each_entry(page, &n->full, slab_list) > + process_slab(&t, s, page, alloc); > + spin_unlock_irqrestore(&n->list_lock, flags); > + } > + > + for (i = 0; i < t.count; i++) { > + struct location *l = &t.loc[i]; > + > + seq_printf(seq, "%7ld ", l->count); > + > + if (l->addr) > + seq_printf(seq, "%pS", (void *)l->addr); > + else > + seq_puts(seq, "<not-available>"); > + > + if (l->sum_time != l->min_time) { > + seq_printf(seq, " age=%ld/%ld/%ld", > + l->min_time, > + (long)div_u64(l->sum_time, l->count), > + l->max_time); > + } else > + seq_printf(seq, " age=%ld", > + l->min_time); > + > + if (l->min_pid != l->max_pid) > + seq_printf(seq, " pid=%ld-%ld", > + l->min_pid, l->max_pid); > + else > + seq_printf(seq, " pid=%ld", > + l->min_pid); > + > + if (num_online_cpus() > 1 && > + !cpumask_empty(to_cpumask(l->cpus))) > + seq_printf(seq, " cpus=%*pbl", > + cpumask_pr_args(to_cpumask(l->cpus))); > + > + if (nr_online_nodes > 1 && !nodes_empty(l->nodes)) > + seq_printf(seq, " nodes=%*pbl", > + nodemask_pr_args(&l->nodes)); > + > + seq_puts(seq, "\n"); > + } > + > + free_loc_track(&t); > + if (!t.count) > + seq_puts(seq, "No data\n"); > + return 0; > +} > + > +static int slab_debug_trace(struct seq_file *seq, void *ignored) > +{ > + struct kmem_cache *s = seq->private; > + > + if (!(s->flags & SLAB_STORE_USER)) > + return 0; > + > + if (strcmp(seq->file->f_path.dentry->d_name.name, "alloc_trace") == 0) > + return list_locations(seq, s, TRACK_ALLOC); > + else > + return list_locations(seq, s, TRACK_FREE); > + > + return 0; > +} > + > +static int slab_debug_trace_open(struct inode *inode, struct file *filp) > +{ > + return single_open(filp, slab_debug_trace, > + file_inode(filp)->i_private); > +} > + > +static const struct file_operations slab_debug_fops = { > + .open = slab_debug_trace_open, > + .read = seq_read, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > +static void debugfs_slab_add(struct kmem_cache *s) > +{ > + if (unlikely(!slab_debugfs_root)) > + return; > + > + slab_debugfs_cache = debugfs_create_dir(s->name, slab_debugfs_root); > + if (!IS_ERR(slab_debugfs_cache)) { > + debugfs_create_file("alloc_trace", 0400, > + slab_debugfs_cache, s, &slab_debug_fops); > + > + debugfs_create_file("free_trace", 0400, > + slab_debugfs_cache, s, &slab_debug_fops); > + } > +} > + > +static void __init slab_debugfs_init(void) > +{ > + struct kmem_cache *s; > + > + slab_debugfs_root = debugfs_create_dir("slab", NULL); > + if (!IS_ERR(slab_debugfs_root)) > + list_for_each_entry(s, &slab_caches, list) > + debugfs_slab_add(s); > + else > + pr_err("Cannot create slab debugfs.\n"); > + > +} > +__initcall(slab_debugfs_init); > +#endif > /* > * The /proc/slabinfo ABI > */ >
