a590359259
Since CMA is getting used more widely, it's more important to keep monitoring CMA statistics for system health since it's directly related to user experience. This patch introduces sysfs statistics for CMA, in order to provide some basic monitoring of the CMA allocator. * the number of CMA page successful allocations * the number of CMA page allocation failures These two values allow the user to calcuate the allocation failure rate for each CMA area. e.g.) /sys/kernel/mm/cma/WIFI/alloc_pages_[success|fail] /sys/kernel/mm/cma/SENSOR/alloc_pages_[success|fail] /sys/kernel/mm/cma/BLUETOOTH/alloc_pages_[success|fail] The cma_stat was intentionally allocated by dynamic allocation to harmonize with kobject lifetime management. https://lore.kernel.org/linux-mm/YCOAmXqt6dZkCQYs@kroah.com/ Link: https://lore.kernel.org/linux-mm/20210324230759.2213957-1-minchan@kernel.org/ Bug: 179256052 Tested-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: https://lore.kernel.org/linux-mm/20210316100433.17665-1-colin.king@canonical.com/ Addresses-Coverity: ("Dereference after null check") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Minchan Kim <minchan@google.com> Change-Id: I86239db91c7853a62a22b2161d1bf8c9099152b7
53 lines
1.4 KiB
C
53 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __MM_CMA_H__
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#define __MM_CMA_H__
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#include <linux/debugfs.h>
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#include <linux/kobject.h>
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struct cma_kobject {
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struct kobject kobj;
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struct cma *cma;
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};
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struct cma {
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unsigned long base_pfn;
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unsigned long count;
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unsigned long *bitmap;
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unsigned int order_per_bit; /* Order of pages represented by one bit */
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struct mutex lock;
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#ifdef CONFIG_CMA_DEBUGFS
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struct hlist_head mem_head;
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spinlock_t mem_head_lock;
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struct debugfs_u32_array dfs_bitmap;
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#endif
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char name[CMA_MAX_NAME];
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#ifdef CONFIG_CMA_SYSFS
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/* the number of CMA page successful allocations */
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atomic64_t nr_pages_succeeded;
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/* the number of CMA page allocation failures */
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atomic64_t nr_pages_failed;
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/* kobject requires dynamic object */
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struct cma_kobject *cma_kobj;
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#endif
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};
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extern struct cma cma_areas[MAX_CMA_AREAS];
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extern unsigned cma_area_count;
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static inline unsigned long cma_bitmap_maxno(struct cma *cma)
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{
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return cma->count >> cma->order_per_bit;
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}
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#ifdef CONFIG_CMA_SYSFS
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void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages);
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void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages);
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#else
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static inline void cma_sysfs_account_success_pages(struct cma *cma,
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unsigned long nr_pages) {};
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static inline void cma_sysfs_account_fail_pages(struct cma *cma,
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unsigned long nr_pages) {};
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#endif
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#endif
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