/* * CMA DebugFS Interface * * Copyright (c) 2015 Sasha Levin */ #include #include #include #include #include #include #include "cma.h" struct cma_mem { struct hlist_node node; struct page *p; unsigned long n; }; static struct dentry *cma_debugfs_root; static int cma_debugfs_get(void *data, u64 *val) { unsigned long *p = data; *val = *p; return 0; } DEFINE_SIMPLE_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n"); static int cma_used_get(void *data, u64 *val) { struct cma *cma = data; unsigned long used; mutex_lock(&cma->lock); /* pages counter is smaller than sizeof(int) */ used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma)); mutex_unlock(&cma->lock); *val = (u64)used << cma->order_per_bit; return 0; } DEFINE_SIMPLE_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n"); static int cma_maxchunk_get(void *data, u64 *val) { struct cma *cma = data; unsigned long maxchunk = 0; unsigned long start, end = 0; unsigned long bitmap_maxno = cma_bitmap_maxno(cma); mutex_lock(&cma->lock); for (;;) { start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end); if (start >= cma->count) break; end = find_next_bit(cma->bitmap, bitmap_maxno, start); maxchunk = max(end - start, maxchunk); } mutex_unlock(&cma->lock); *val = (u64)maxchunk << cma->order_per_bit; return 0; } DEFINE_SIMPLE_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n"); static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem) { spin_lock(&cma->mem_head_lock); hlist_add_head(&mem->node, &cma->mem_head); spin_unlock(&cma->mem_head_lock); } static struct cma_mem *cma_get_entry_from_list(struct cma *cma) { struct cma_mem *mem = NULL; spin_lock(&cma->mem_head_lock); if (!hlist_empty(&cma->mem_head)) { mem = hlist_entry(cma->mem_head.first, struct cma_mem, node); hlist_del_init(&mem->node); } spin_unlock(&cma->mem_head_lock); return mem; } static int cma_free_mem(struct cma *cma, int count) { struct cma_mem *mem = NULL; while (count) { mem = cma_get_entry_from_list(cma); if (mem == NULL) return 0; if (mem->n <= count) { cma_release(cma, mem->p, mem->n); count -= mem->n; kfree(mem); } else if (cma->order_per_bit == 0) { cma_release(cma, mem->p, count); mem->p += count; mem->n -= count; count = 0; cma_add_to_cma_mem_list(cma, mem); } else { pr_debug("cma: cannot release partial block when order_per_bit != 0\n"); cma_add_to_cma_mem_list(cma, mem); break; } } return 0; } static int cma_free_write(void *data, u64 val) { int pages = val; struct cma *cma = data; return cma_free_mem(cma, pages); } DEFINE_SIMPLE_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); static int cma_alloc_mem(struct cma *cma, int count) { struct cma_mem *mem; struct page *p; mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; p = cma_alloc(cma, count, 0); if (!p) { kfree(mem); return -ENOMEM; } mem->p = p; mem->n = count; cma_add_to_cma_mem_list(cma, mem); return 0; } static int cma_alloc_write(void *data, u64 val) { int pages = val; struct cma *cma = data; return cma_alloc_mem(cma, pages); } DEFINE_SIMPLE_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n"); static void cma_debugfs_add_one(struct cma *cma, int idx) { struct dentry *tmp; char name[16]; int u32s; sprintf(name, "cma-%d", idx); tmp = debugfs_create_dir(name, cma_debugfs_root); debugfs_create_file("alloc", S_IWUSR, tmp, cma, &cma_alloc_fops); debugfs_create_file("free", S_IWUSR, tmp, cma, &cma_free_fops); debugfs_create_file("base_pfn", S_IRUGO, tmp, &cma->base_pfn, &cma_debugfs_fops); debugfs_create_file("count", S_IRUGO, tmp, &cma->count, &cma_debugfs_fops); debugfs_create_file("order_per_bit", S_IRUGO, tmp, &cma->order_per_bit, &cma_debugfs_fops); debugfs_create_file("used", S_IRUGO, tmp, cma, &cma_used_fops); debugfs_create_file("maxchunk", S_IRUGO, tmp, cma, &cma_maxchunk_fops); u32s = DIV_ROUND_UP(cma_bitmap_maxno(cma), BITS_PER_BYTE * sizeof(u32)); debugfs_create_u32_array("bitmap", S_IRUGO, tmp, (u32*)cma->bitmap, u32s); } static int __init cma_debugfs_init(void) { int i; cma_debugfs_root = debugfs_create_dir("cma", NULL); if (!cma_debugfs_root) return -ENOMEM; for (i = 0; i < cma_area_count; i++) cma_debugfs_add_one(&cma_areas[i], i); return 0; } late_initcall(cma_debugfs_init); >40space:mode:
authorThomas Gleixner <tglx@linutronix.de>2017-01-31 23:58:38 +0100
committerIngo Molnar <mingo@kernel.org>2017-02-01 08:37:27 +0100
commitdd86e373e09fb16b83e8adf5c48c421a4ca76468 (patch)
tree55703c2ea8584e303e342090614e0aab3509ab21 /tools/perf/Documentation/Makefile
parent0b3589be9b98994ce3d5aeca52445d1f5627c4ba (diff)
perf/x86/intel/rapl: Make package handling more robust
The package management code in RAPL relies on package mapping being available before a CPU is started. This changed with: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") because the ACPI/BIOS information turned out to be unreliable, but that left RAPL in broken state. This was not noticed because on a regular boot all CPUs are online before RAPL is initialized. A possible fix would be to reintroduce the mess which allocates a package data structure in CPU prepare and when it turns out to already exist in starting throw it away later in the CPU online callback. But that's a horrible hack and not required at all because RAPL becomes functional for perf only in the CPU online callback. That's correct because user space is not yet informed about the CPU being onlined, so nothing caan rely on RAPL being available on that particular CPU. Move the allocation to the CPU online callback and simplify the hotplug handling. At this point the package mapping is established and correct. This also adds a missing check for available package data in the event_init() function. Reported-by: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Fixes: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust") Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'tools/perf/Documentation/Makefile')