diff options
| -rw-r--r-- | util/qsp.c | 49 |
1 files changed, 8 insertions, 41 deletions
@@ -84,13 +84,6 @@ struct QSPEntry { uint64_t n_acqs; uint64_t ns; unsigned int n_objs; /* count of coalesced objs; only used for reporting */ -#ifndef CONFIG_ATOMIC64 - /* - * If we cannot update the counts atomically, then use a seqlock. - * We don't need an associated lock because the updates are thread-local. - */ - QemuSeqLock sequence; -#endif }; typedef struct QSPEntry QSPEntry; @@ -345,46 +338,15 @@ static QSPEntry *qsp_entry_get(const void *obj, const char *file, int line, } /* - * @from is in the global hash table; read it atomically if the host - * supports it, otherwise use the seqlock. - */ -static void qsp_entry_aggregate(QSPEntry *to, const QSPEntry *from) -{ -#ifdef CONFIG_ATOMIC64 - to->ns += atomic_read__nocheck(&from->ns); - to->n_acqs += atomic_read__nocheck(&from->n_acqs); -#else - unsigned int version; - uint64_t ns, n_acqs; - - do { - version = seqlock_read_begin(&from->sequence); - ns = atomic_read__nocheck(&from->ns); - n_acqs = atomic_read__nocheck(&from->n_acqs); - } while (seqlock_read_retry(&from->sequence, version)); - - to->ns += ns; - to->n_acqs += n_acqs; -#endif -} - -/* * @e is in the global hash table; it is only written to by the current thread, * so we write to it atomically (as in "write once") to prevent torn reads. - * If the host doesn't support u64 atomics, use the seqlock. */ static inline void do_qsp_entry_record(QSPEntry *e, int64_t delta, bool acq) { -#ifndef CONFIG_ATOMIC64 - seqlock_write_begin(&e->sequence); -#endif - atomic_set__nocheck(&e->ns, e->ns + delta); + atomic_set_u64(&e->ns, e->ns + delta); if (acq) { - atomic_set__nocheck(&e->n_acqs, e->n_acqs + 1); + atomic_set_u64(&e->n_acqs, e->n_acqs + 1); } -#ifndef CONFIG_ATOMIC64 - seqlock_write_end(&e->sequence); -#endif } static inline void qsp_entry_record(QSPEntry *e, int64_t delta) @@ -550,7 +512,12 @@ static void qsp_aggregate(void *p, uint32_t h, void *up) hash = qsp_entry_no_thread_hash(e); agg = qsp_entry_find(ht, e, hash); - qsp_entry_aggregate(agg, e); + /* + * The entry is in the global hash table; read from it atomically (as in + * "read once"). + */ + agg->ns += atomic_read_u64(&e->ns); + agg->n_acqs += atomic_read_u64(&e->n_acqs); } static void qsp_iter_diff(void *p, uint32_t hash, void *htp) |