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([180.233.125.201]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2a7190ca9d5sm6527975ad.25.2026.01.15.19.39.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Jan 2026 19:39:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1768534786; x=1769139586; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=pWKD7qvJhqwZTehtXTMdJknW4/xJt4QHquzuA5hb+vE=; b=FyLm3Tj9sHJdUlcnZomeQqsDTzRybT3i42QWRoQYj7+EUi3l9JKumKpqUiCfFLMQ7G UXG3z3Y/a60rG9Bx50rRKoMD81kadbCo7CsNUGagJMVxR6idqiVaJpB5AfTVwaRHZx9x 3heqKeuzTcs/KKNGgGfFZtchoBOQvZrS6Of5Gtmfp9+69Pv8RLZH8qZwgIMU3KXhfuGe VTfw91hijgB17zXP9b+TETy9CYr/UO3oKoFq4FeKThxMdVC4OZCamtNLw6ngAa8zPMbP zcTFa1lK0LaOPbwPGuZy9eM4kEQfonL9anWRBEM7MaOQkgzXp3jhJe4bqJI9D16tVftQ xl+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1768534786; x=1769139586; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=pWKD7qvJhqwZTehtXTMdJknW4/xJt4QHquzuA5hb+vE=; b=E/KrYqgSiyha7Ay5bhk3MR1GcUZlbZR0Ns48XEssy1OiyZwwb41ZtnVXObFB63OPFd YiREwyOrctgrNuHggdTIIrBZfVhmMHMXTQFEA9x0/JySNiQc3npSVvQTbJZ8kjbFyrzw xfUnHKjZ3sSBiIj7UAjWUhRqJaKSXYi8PFGiz7IJmCPeEI0I45OLny7I6jyiWFMZQKh2 6PUgqeUMX2Dso375+olahsuqobKpNJD+n+NizANVDsnz5/oSUyeh1dlpUqBwQXNpgaXF eHb3hx1KLWpkQOs8GtRW3h28fGC0TscZuMhBRqTFWzcertrYiLp8riMlqLxPd4Eu4ivc PTaA== X-Gm-Message-State: AOJu0Yx9WEHQBpa/AtcmLyHLnC5mDSx0PX2UsfHYaTFEn6uDqWMx0z4e h1A9qAlQr304p1Slgf/9xj66nXsmO74YK8msBoo6CXLNHYhGLTaV8Ylwyc1kev7ZFHv5iA/KGoo l1q7xCYooww== X-Gm-Gg: AY/fxX6NiAR0DhXQymWOM96OjIsxdQ3KHp8v7Dax2qXE9ZikgAd7oGfz9LR6vbxh9zs Lm9+eMweXBUqEhBxOFQuZTzGgy7cYuKDmL4DTGYSE0DywLrQYbjslEMsXNoWjtiGeiORD0PJKnD BNfYSIRvEUJpx1SHwcH/PsxMMQikgnDnivYQX7qYPXziL7f6SrAkrlksf4KadQ6RGowP90wB/aN J8D6FTBAzL6XEM5dvYS950GAOBPBLH54SOFuTSmxW1o71Uyvf6rwPSKMSeJkaB/zWGqSxHYe4ta SsaEG/gXOHxL/ElrrtMWRqX/chYB4woWcIafSpLc3iq7D8k6K+9WNv/JChENCA3b6hRqrv90GL0 Nr6bW3he1aKiaxmoSe4goakISJvuhKqr5KTX7x3zPR5djdbJdNa2gmRDAxzXced9D+ajVIyTEZf p4RcHDQDoOmJ050mgfsw== X-Received: by 2002:a17:903:120b:b0:297:cf96:45bd with SMTP id d9443c01a7336-2a717537567mr15097245ad.19.1768534786441; Thu, 15 Jan 2026 19:39:46 -0800 (PST) From: Richard Henderson To: qemu-devel@nongnu.org Cc: ktokunaga.mail@gmail.com, berrange@redhat.com, pierrick.bouvier@linaro.org, thuth@redhat.com, pbonzini@redhat.com, philmd@linaro.org Subject: [PATCH v2 55/58] util: Remove stats64 Date: Fri, 16 Jan 2026 14:33:01 +1100 Message-ID: <20260116033305.51162-56-richard.henderson@linaro.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260116033305.51162-1-richard.henderson@linaro.org> References: <20260116033305.51162-1-richard.henderson@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2607:f8b0:4864:20::635; envelope-from=richard.henderson@linaro.org; helo=mail-pl1-x635.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @linaro.org) X-ZM-MESSAGEID: 1768535312455158500 Content-Type: text/plain; charset="utf-8" This API is no longer used. Reviewed-by: Pierrick Bouvier Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- include/qemu/stats64.h | 199 ----------------------------------------- util/stats64.c | 148 ------------------------------ util/meson.build | 1 - 3 files changed, 348 deletions(-) delete mode 100644 include/qemu/stats64.h delete mode 100644 util/stats64.c diff --git a/include/qemu/stats64.h b/include/qemu/stats64.h deleted file mode 100644 index 99b5cb724a..0000000000 --- a/include/qemu/stats64.h +++ /dev/null @@ -1,199 +0,0 @@ -/* - * Atomic operations on 64-bit quantities. - * - * Copyright (C) 2017 Red Hat, Inc. - * - * Author: Paolo Bonzini - * - * This work is licensed under the terms of the GNU GPL, version 2 or late= r. - * See the COPYING file in the top-level directory. - */ - -#ifndef QEMU_STATS64_H -#define QEMU_STATS64_H - -#include "qemu/atomic.h" - -/* This provides atomic operations on 64-bit type, using a reader-writer - * spinlock on architectures that do not have 64-bit accesses. Even on - * those architectures, it tries hard not to take the lock. - */ - -typedef struct Stat64 { -#ifdef CONFIG_ATOMIC64 - aligned_uint64_t value; -#else - uint32_t low, high; - uint32_t lock; -#endif -} Stat64; - -#ifdef CONFIG_ATOMIC64 -static inline void stat64_init(Stat64 *s, uint64_t value) -{ - /* This is not guaranteed to be atomic! */ - *s =3D (Stat64) { value }; -} - -static inline uint64_t stat64_get(const Stat64 *s) -{ - return qatomic_read__nocheck(&s->value); -} - -static inline void stat64_set(Stat64 *s, uint64_t value) -{ - qatomic_set__nocheck(&s->value, value); -} - -static inline void stat64_add(Stat64 *s, uint64_t value) -{ - qatomic_add(&s->value, value); -} - -static inline void stat64_min(Stat64 *s, uint64_t value) -{ - uint64_t orig =3D qatomic_read__nocheck(&s->value); - while (orig > value) { - orig =3D qatomic_cmpxchg__nocheck(&s->value, orig, value); - } -} - -static inline void stat64_max(Stat64 *s, uint64_t value) -{ - uint64_t orig =3D qatomic_read__nocheck(&s->value); - while (orig < value) { - orig =3D qatomic_cmpxchg__nocheck(&s->value, orig, value); - } -} -#else -uint64_t stat64_get(const Stat64 *s); -void stat64_set(Stat64 *s, uint64_t value); -bool stat64_min_slow(Stat64 *s, uint64_t value); -bool stat64_max_slow(Stat64 *s, uint64_t value); -bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high); - -static inline void stat64_init(Stat64 *s, uint64_t value) -{ - /* This is not guaranteed to be atomic! */ - *s =3D (Stat64) { .low =3D value, .high =3D value >> 32, .lock =3D 0 }; -} - -static inline void stat64_add(Stat64 *s, uint64_t value) -{ - uint32_t low, high; - high =3D value >> 32; - low =3D (uint32_t) value; - if (!low) { - if (high) { - qatomic_add(&s->high, high); - } - return; - } - - for (;;) { - uint32_t orig =3D s->low; - uint32_t result =3D orig + low; - uint32_t old; - - if (result < low || high) { - /* If the high part is affected, take the lock. */ - if (stat64_add32_carry(s, low, high)) { - return; - } - continue; - } - - /* No carry, try with a 32-bit cmpxchg. The result is independent= of - * the high 32 bits, so it can race just fine with stat64_add32_ca= rry - * and even stat64_get! - */ - old =3D qatomic_cmpxchg(&s->low, orig, result); - if (orig =3D=3D old) { - return; - } - } -} - -static inline void stat64_min(Stat64 *s, uint64_t value) -{ - uint32_t low, high; - uint32_t orig_low, orig_high; - - high =3D value >> 32; - low =3D (uint32_t) value; - do { - orig_high =3D qatomic_read(&s->high); - if (orig_high < high) { - return; - } - - if (orig_high =3D=3D high) { - /* High 32 bits are equal. Read low after high, otherwise we - * can get a false positive (e.g. 0x1235,0x0000 changes to - * 0x1234,0x8000 and we read it as 0x1234,0x0000). Pairs with - * the write barrier in stat64_min_slow. - */ - smp_rmb(); - orig_low =3D qatomic_read(&s->low); - if (orig_low <=3D low) { - return; - } - - /* See if we were lucky and a writer raced against us. The - * barrier is theoretically unnecessary, but if we remove it - * we may miss being lucky. - */ - smp_rmb(); - orig_high =3D qatomic_read(&s->high); - if (orig_high < high) { - return; - } - } - - /* If the value changes in any way, we have to take the lock. */ - } while (!stat64_min_slow(s, value)); -} - -static inline void stat64_max(Stat64 *s, uint64_t value) -{ - uint32_t low, high; - uint32_t orig_low, orig_high; - - high =3D value >> 32; - low =3D (uint32_t) value; - do { - orig_high =3D qatomic_read(&s->high); - if (orig_high > high) { - return; - } - - if (orig_high =3D=3D high) { - /* High 32 bits are equal. Read low after high, otherwise we - * can get a false positive (e.g. 0x1234,0x8000 changes to - * 0x1235,0x0000 and we read it as 0x1235,0x8000). Pairs with - * the write barrier in stat64_max_slow. - */ - smp_rmb(); - orig_low =3D qatomic_read(&s->low); - if (orig_low >=3D low) { - return; - } - - /* See if we were lucky and a writer raced against us. The - * barrier is theoretically unnecessary, but if we remove it - * we may miss being lucky. - */ - smp_rmb(); - orig_high =3D qatomic_read(&s->high); - if (orig_high > high) { - return; - } - } - - /* If the value changes in any way, we have to take the lock. */ - } while (!stat64_max_slow(s, value)); -} - -#endif - -#endif diff --git a/util/stats64.c b/util/stats64.c deleted file mode 100644 index 09736014ec..0000000000 --- a/util/stats64.c +++ /dev/null @@ -1,148 +0,0 @@ -/* - * Atomic operations on 64-bit quantities. - * - * Copyright (C) 2017 Red Hat, Inc. - * - * Author: Paolo Bonzini - * - * This work is licensed under the terms of the GNU GPL, version 2 or late= r. - * See the COPYING file in the top-level directory. - */ - -#include "qemu/osdep.h" -#include "qemu/atomic.h" -#include "qemu/stats64.h" -#include "qemu/processor.h" - -#ifndef CONFIG_ATOMIC64 -static inline void stat64_rdlock(Stat64 *s) -{ - /* Keep out incoming writers to avoid them starving us. */ - qatomic_add(&s->lock, 2); - - /* If there is a concurrent writer, wait for it. */ - while (qatomic_read(&s->lock) & 1) { - cpu_relax(); - } -} - -static inline void stat64_rdunlock(Stat64 *s) -{ - qatomic_sub(&s->lock, 2); -} - -static inline bool stat64_wrtrylock(Stat64 *s) -{ - return qatomic_cmpxchg(&s->lock, 0, 1) =3D=3D 0; -} - -static inline void stat64_wrunlock(Stat64 *s) -{ - qatomic_dec(&s->lock); -} - -uint64_t stat64_get(const Stat64 *s) -{ - uint32_t high, low; - - stat64_rdlock((Stat64 *)s); - - /* 64-bit writes always take the lock, so we can read in - * any order. - */ - high =3D qatomic_read(&s->high); - low =3D qatomic_read(&s->low); - stat64_rdunlock((Stat64 *)s); - - return ((uint64_t)high << 32) | low; -} - -void stat64_set(Stat64 *s, uint64_t val) -{ - while (!stat64_wrtrylock(s)) { - cpu_relax(); - } - - qatomic_set(&s->high, val >> 32); - qatomic_set(&s->low, val); - stat64_wrunlock(s); -} - -bool stat64_add32_carry(Stat64 *s, uint32_t low, uint32_t high) -{ - uint32_t old; - - if (!stat64_wrtrylock(s)) { - cpu_relax(); - return false; - } - - /* 64-bit reads always take the lock, so they don't care about the - * order of our update. By updating s->low first, we can check - * whether we have to carry into s->high. - */ - old =3D qatomic_fetch_add(&s->low, low); - high +=3D (old + low) < old; - qatomic_add(&s->high, high); - stat64_wrunlock(s); - return true; -} - -bool stat64_min_slow(Stat64 *s, uint64_t value) -{ - uint32_t high, low; - uint64_t orig; - - if (!stat64_wrtrylock(s)) { - cpu_relax(); - return false; - } - - high =3D qatomic_read(&s->high); - low =3D qatomic_read(&s->low); - - orig =3D ((uint64_t)high << 32) | low; - if (value < orig) { - /* We have to set low before high, just like stat64_min reads - * high before low. The value may become higher temporarily, but - * stat64_get does not notice (it takes the lock) and the only ill - * effect on stat64_min is that the slow path may be triggered - * unnecessarily. - */ - qatomic_set(&s->low, (uint32_t)value); - smp_wmb(); - qatomic_set(&s->high, value >> 32); - } - stat64_wrunlock(s); - return true; -} - -bool stat64_max_slow(Stat64 *s, uint64_t value) -{ - uint32_t high, low; - uint64_t orig; - - if (!stat64_wrtrylock(s)) { - cpu_relax(); - return false; - } - - high =3D qatomic_read(&s->high); - low =3D qatomic_read(&s->low); - - orig =3D ((uint64_t)high << 32) | low; - if (value > orig) { - /* We have to set low before high, just like stat64_max reads - * high before low. The value may become lower temporarily, but - * stat64_get does not notice (it takes the lock) and the only ill - * effect on stat64_max is that the slow path may be triggered - * unnecessarily. - */ - qatomic_set(&s->low, (uint32_t)value); - smp_wmb(); - qatomic_set(&s->high, value >> 32); - } - stat64_wrunlock(s); - return true; -} -#endif diff --git a/util/meson.build b/util/meson.build index 35029380a3..d7d6b213f6 100644 --- a/util/meson.build +++ b/util/meson.build @@ -59,7 +59,6 @@ util_ss.add(files('qht.c')) util_ss.add(files('qsp.c')) util_ss.add(files('range.c')) util_ss.add(files('reserved-region.c')) -util_ss.add(files('stats64.c')) util_ss.add(files('systemd.c')) util_ss.add(files('transactions.c')) util_ss.add(files('guest-random.c')) --=20 2.43.0