From patchwork Mon Jan 14 16:50:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Emilio Cota X-Patchwork-Id: 10763185 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 238066C2 for ; Mon, 14 Jan 2019 16:58:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1024723B34 for ; Mon, 14 Jan 2019 16:58:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 03EB128761; Mon, 14 Jan 2019 16:58:28 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B972023B34 for ; Mon, 14 Jan 2019 16:58:16 +0000 (UTC) Received: from localhost ([127.0.0.1]:45940 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj5Z2-0004g8-0K for patchwork-qemu-devel@patchwork.kernel.org; Mon, 14 Jan 2019 11:58:16 -0500 Received: from eggs.gnu.org ([209.51.188.92]:38234) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gj5RZ-0006oq-Vi for qemu-devel@nongnu.org; Mon, 14 Jan 2019 11:50:36 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gj5RW-0001xP-PZ for qemu-devel@nongnu.org; Mon, 14 Jan 2019 11:50:33 -0500 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:38229) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gj5RW-0001u9-Fw for qemu-devel@nongnu.org; Mon, 14 Jan 2019 11:50:30 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 0170829D4E; Mon, 14 Jan 2019 11:50:21 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Mon, 14 Jan 2019 11:50:21 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=braap.org; h= from:to:cc:subject:date:message-id:in-reply-to:references; s= mesmtp; bh=8PVy3vG5QOjwkXJVg3FQAFsrEPjCOhO13bEBZVWzECM=; b=DyVnu 8fnl/qpWMq+RFz/RLRmg/uDnB8DcVz44NhMzx4cHn0C9EA0hg5X8x7AkmRN+b82o EYzVEymBfcxMZK2BpYwxtgauP7KMv8JntiW/MVTHdhAX+DDKhrqwEeKcREq9cj5K l0GzfdcJ+rdTHdQSEUVrj45ME8mLfvJPtWK46c= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-proxy:x-me-proxy:x-me-sender :x-me-sender:x-sasl-enc; s=fm1; bh=8PVy3vG5QOjwkXJVg3FQAFsrEPjCO hO13bEBZVWzECM=; b=e3iVrVH007jzv4Fud10SjS7T1vDlQCM0ep3E14D8RXysC W/inINHztaCYFGSqf2YmB8p3QTvpM9VNN3kUo9zFiasDgt1lY7t3+d3/hevJF2c7 SHZ19K07t/D2IJNUv+LvqVsWbQxTNFVutcwuscdrXPW2krBCsse78IIZGTyhCipw djL0KchbP777AiaO17b+Tnf6jiF/BhDDXb1rO0A2U2s4LSN9oJlhBl0XevnA2mxu SyR9vZFtgu45IA+oogokSriMu4mJEttPx3MjHvxQ7r/L/NiWKBBavz1Ap//R1lX+ Imtw0J2aybij4FWKlqOZMNJ/cboQQV6gPMNKLAC3g== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedtledrgedugdelfecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfhuthenuceurghilhhouhhtmecufedt tdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkffojg hfsedttdertdertddtnecuhfhrohhmpedfgfhmihhlihhoucfirdcuvehothgrfdcuoegt ohhtrgessghrrggrphdrohhrgheqnecukfhppeduvdekrdehledrvddtrddvudeinecurf grrhgrmhepmhgrihhlfhhrohhmpegtohhtrgessghrrggrphdrohhrghenucevlhhushht vghrufhiiigvpedt X-ME-Proxy: Received: from localhost (flamenco.cs.columbia.edu [128.59.20.216]) by mail.messagingengine.com (Postfix) with ESMTPA id 9F78E102DD; Mon, 14 Jan 2019 11:50:20 -0500 (EST) From: "Emilio G. Cota" To: qemu-devel@nongnu.org Date: Mon, 14 Jan 2019 11:50:16 -0500 Message-Id: <20190114165017.27298-3-cota@braap.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190114165017.27298-1-cota@braap.org> References: <20190114165017.27298-1-cota@braap.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.111.4.27 Subject: [Qemu-devel] [PATCH v6 2/3] tcg: introduce dynamic TLB sizing X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Alex_Benn=C3=A9e?= , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP Disabled in all TCG backends for now. Signed-off-by: Emilio G. Cota --- include/exec/cpu-defs.h | 57 ++++++++++- include/exec/cpu_ldst.h | 21 ++++ tcg/aarch64/tcg-target.h | 1 + tcg/arm/tcg-target.h | 1 + tcg/i386/tcg-target.h | 1 + tcg/mips/tcg-target.h | 1 + tcg/ppc/tcg-target.h | 1 + tcg/s390/tcg-target.h | 1 + tcg/sparc/tcg-target.h | 1 + tcg/tci/tcg-target.h | 1 + accel/tcg/cputlb.c | 202 ++++++++++++++++++++++++++++++++++++++- 11 files changed, 281 insertions(+), 7 deletions(-) diff --git a/include/exec/cpu-defs.h b/include/exec/cpu-defs.h index 6a60f94a41..191a1e021f 100644 --- a/include/exec/cpu-defs.h +++ b/include/exec/cpu-defs.h @@ -67,6 +67,28 @@ typedef uint64_t target_ulong; #define CPU_TLB_ENTRY_BITS 5 #endif +#if TCG_TARGET_IMPLEMENTS_DYN_TLB +#define CPU_TLB_DYN_MIN_BITS 6 +#define CPU_TLB_DYN_DEFAULT_BITS 8 + + +# if HOST_LONG_BITS == 32 +/* Make sure we do not require a double-word shift for the TLB load */ +# define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS) +# else /* HOST_LONG_BITS == 64 */ +/* + * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) == + * 2**34 == 16G of address space. This is roughly what one would expect a + * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel + * Skylake's Level-2 STLB has 16 1G entries. + * Also, make sure we do not size the TLB past the guest's address space. + */ +# define CPU_TLB_DYN_MAX_BITS \ + MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS) +# endif + +#else /* !TCG_TARGET_IMPLEMENTS_DYN_TLB */ + /* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that * the TLB is not unnecessarily small, but still small enough for the * TLB lookup instruction sequence used by the TCG target. @@ -98,6 +120,7 @@ typedef uint64_t target_ulong; NB_MMU_MODES <= 8 ? 3 : 4)) #define CPU_TLB_SIZE (1 << CPU_TLB_BITS) +#endif /* TCG_TARGET_IMPLEMENTS_DYN_TLB */ typedef struct CPUTLBEntry { /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address @@ -141,6 +164,18 @@ typedef struct CPUIOTLBEntry { MemTxAttrs attrs; } CPUIOTLBEntry; +/** + * struct CPUTLBWindow + * @begin_ns: host time (in ns) at the beginning of the time window + * @max_entries: maximum number of entries observed in the window + * + * See also: tlb_mmu_resize_locked() + */ +typedef struct CPUTLBWindow { + int64_t begin_ns; + size_t max_entries; +} CPUTLBWindow; + typedef struct CPUTLBDesc { /* * Describe a region covering all of the large pages allocated @@ -152,6 +187,10 @@ typedef struct CPUTLBDesc { target_ulong large_page_mask; /* The next index to use in the tlb victim table. */ size_t vindex; +#if TCG_TARGET_IMPLEMENTS_DYN_TLB + CPUTLBWindow window; + size_t n_used_entries; +#endif } CPUTLBDesc; /* @@ -176,6 +215,20 @@ typedef struct CPUTLBCommon { size_t elide_flush_count; } CPUTLBCommon; +#if TCG_TARGET_IMPLEMENTS_DYN_TLB +# define CPU_TLB \ + /* tlb_mask[i] contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */ \ + uintptr_t tlb_mask[NB_MMU_MODES]; \ + CPUTLBEntry *tlb_table[NB_MMU_MODES]; +# define CPU_IOTLB \ + CPUIOTLBEntry *iotlb[NB_MMU_MODES]; +#else +# define CPU_TLB \ + CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE]; +# define CPU_IOTLB \ + CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE]; +#endif + /* * The meaning of each of the MMU modes is defined in the target code. * Note that NB_MMU_MODES is not yet defined; we can only reference it @@ -184,9 +237,9 @@ typedef struct CPUTLBCommon { #define CPU_COMMON_TLB \ CPUTLBCommon tlb_c; \ CPUTLBDesc tlb_d[NB_MMU_MODES]; \ - CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE]; \ + CPU_TLB \ CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE]; \ - CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE]; \ + CPU_IOTLB \ CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE]; #else diff --git a/include/exec/cpu_ldst.h b/include/exec/cpu_ldst.h index 959068495a..83b2907d86 100644 --- a/include/exec/cpu_ldst.h +++ b/include/exec/cpu_ldst.h @@ -135,6 +135,21 @@ static inline target_ulong tlb_addr_write(const CPUTLBEntry *entry) #endif } +#if TCG_TARGET_IMPLEMENTS_DYN_TLB +/* Find the TLB index corresponding to the mmu_idx + address pair. */ +static inline uintptr_t tlb_index(CPUArchState *env, uintptr_t mmu_idx, + target_ulong addr) +{ + uintptr_t size_mask = env->tlb_mask[mmu_idx] >> CPU_TLB_ENTRY_BITS; + + return (addr >> TARGET_PAGE_BITS) & size_mask; +} + +static inline size_t tlb_n_entries(CPUArchState *env, uintptr_t mmu_idx) +{ + return (env->tlb_mask[mmu_idx] >> CPU_TLB_ENTRY_BITS) + 1; +} +#else /* Find the TLB index corresponding to the mmu_idx + address pair. */ static inline uintptr_t tlb_index(CPUArchState *env, uintptr_t mmu_idx, target_ulong addr) @@ -142,6 +157,12 @@ static inline uintptr_t tlb_index(CPUArchState *env, uintptr_t mmu_idx, return (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1); } +static inline size_t tlb_n_entries(CPUArchState *env, uintptr_t mmu_idx) +{ + return CPU_TLB_SIZE; +} +#endif /* TCG_TARGET_IMPLEMENTS_DYN_TLB */ + /* Find the TLB entry corresponding to the mmu_idx + address pair. */ static inline CPUTLBEntry *tlb_entry(CPUArchState *env, uintptr_t mmu_idx, target_ulong addr) diff --git a/tcg/aarch64/tcg-target.h b/tcg/aarch64/tcg-target.h index f966a4fcb3..bff91c5aa0 100644 --- a/tcg/aarch64/tcg-target.h +++ b/tcg/aarch64/tcg-target.h @@ -15,6 +15,7 @@ #define TCG_TARGET_INSN_UNIT_SIZE 4 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 24 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 #undef TCG_TARGET_STACK_GROWSUP typedef enum { diff --git a/tcg/arm/tcg-target.h b/tcg/arm/tcg-target.h index 16172f73a3..c5a7064bdc 100644 --- a/tcg/arm/tcg-target.h +++ b/tcg/arm/tcg-target.h @@ -60,6 +60,7 @@ extern int arm_arch; #undef TCG_TARGET_STACK_GROWSUP #define TCG_TARGET_INSN_UNIT_SIZE 4 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 16 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 typedef enum { TCG_REG_R0 = 0, diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h index f378d29568..bd7d37c7ef 100644 --- a/tcg/i386/tcg-target.h +++ b/tcg/i386/tcg-target.h @@ -27,6 +27,7 @@ #define TCG_TARGET_INSN_UNIT_SIZE 1 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 31 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 #ifdef __x86_64__ # define TCG_TARGET_REG_BITS 64 diff --git a/tcg/mips/tcg-target.h b/tcg/mips/tcg-target.h index 5cb8672470..8600eefd9a 100644 --- a/tcg/mips/tcg-target.h +++ b/tcg/mips/tcg-target.h @@ -37,6 +37,7 @@ #define TCG_TARGET_INSN_UNIT_SIZE 4 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 16 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 #define TCG_TARGET_NB_REGS 32 typedef enum { diff --git a/tcg/ppc/tcg-target.h b/tcg/ppc/tcg-target.h index 52c1bb04b1..b51854b5cf 100644 --- a/tcg/ppc/tcg-target.h +++ b/tcg/ppc/tcg-target.h @@ -34,6 +34,7 @@ #define TCG_TARGET_NB_REGS 32 #define TCG_TARGET_INSN_UNIT_SIZE 4 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 16 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 typedef enum { TCG_REG_R0, TCG_REG_R1, TCG_REG_R2, TCG_REG_R3, diff --git a/tcg/s390/tcg-target.h b/tcg/s390/tcg-target.h index 853ed6e7aa..394b545369 100644 --- a/tcg/s390/tcg-target.h +++ b/tcg/s390/tcg-target.h @@ -27,6 +27,7 @@ #define TCG_TARGET_INSN_UNIT_SIZE 2 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 19 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 typedef enum TCGReg { TCG_REG_R0 = 0, diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h index a0ed2a3342..dc0a227890 100644 --- a/tcg/sparc/tcg-target.h +++ b/tcg/sparc/tcg-target.h @@ -29,6 +29,7 @@ #define TCG_TARGET_INSN_UNIT_SIZE 4 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 32 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 #define TCG_TARGET_NB_REGS 32 typedef enum { diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h index 086f34e69a..816dc4697c 100644 --- a/tcg/tci/tcg-target.h +++ b/tcg/tci/tcg-target.h @@ -43,6 +43,7 @@ #define TCG_TARGET_INTERPRETER 1 #define TCG_TARGET_INSN_UNIT_SIZE 1 #define TCG_TARGET_TLB_DISPLACEMENT_BITS 32 +#define TCG_TARGET_IMPLEMENTS_DYN_TLB 0 #if UINTPTR_MAX == UINT32_MAX # define TCG_TARGET_REG_BITS 32 diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index 5dc97212a9..f1ffc4088b 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -74,6 +74,187 @@ QEMU_BUILD_BUG_ON(sizeof(target_ulong) > sizeof(run_on_cpu_data)); QEMU_BUILD_BUG_ON(NB_MMU_MODES > 16); #define ALL_MMUIDX_BITS ((1 << NB_MMU_MODES) - 1) +#if TCG_TARGET_IMPLEMENTS_DYN_TLB +static inline size_t sizeof_tlb(CPUArchState *env, uintptr_t mmu_idx) +{ + return env->tlb_mask[mmu_idx] + (1 << CPU_TLB_ENTRY_BITS); +} + +static void tlb_window_reset(CPUTLBWindow *window, int64_t ns, + size_t max_entries) +{ + window->begin_ns = ns; + window->max_entries = max_entries; +} + +static void tlb_dyn_init(CPUArchState *env) +{ + int i; + + for (i = 0; i < NB_MMU_MODES; i++) { + CPUTLBDesc *desc = &env->tlb_d[i]; + size_t n_entries = 1 << CPU_TLB_DYN_DEFAULT_BITS; + + tlb_window_reset(&desc->window, get_clock_realtime(), 0); + desc->n_used_entries = 0; + env->tlb_mask[i] = (n_entries - 1) << CPU_TLB_ENTRY_BITS; + env->tlb_table[i] = g_new(CPUTLBEntry, n_entries); + env->iotlb[i] = g_new(CPUIOTLBEntry, n_entries); + } +} + +/** + * tlb_mmu_resize_locked() - perform TLB resize bookkeeping; resize if necessary + * @env: CPU that owns the TLB + * @mmu_idx: MMU index of the TLB + * + * Called with tlb_lock_held. + * + * We have two main constraints when resizing a TLB: (1) we only resize it + * on a TLB flush (otherwise we'd have to take a perf hit by either rehashing + * the array or unnecessarily flushing it), which means we do not control how + * frequently the resizing can occur; (2) we don't have access to the guest's + * future scheduling decisions, and therefore have to decide the magnitude of + * the resize based on past observations. + * + * In general, a memory-hungry process can benefit greatly from an appropriately + * sized TLB, since a guest TLB miss is very expensive. This doesn't mean that + * we just have to make the TLB as large as possible; while an oversized TLB + * results in minimal TLB miss rates, it also takes longer to be flushed + * (flushes can be _very_ frequent), and the reduced locality can also hurt + * performance. + * + * To achieve near-optimal performance for all kinds of workloads, we: + * + * 1. Aggressively increase the size of the TLB when the use rate of the + * TLB being flushed is high, since it is likely that in the near future this + * memory-hungry process will execute again, and its memory hungriness will + * probably be similar. + * + * 2. Slowly reduce the size of the TLB as the use rate declines over a + * reasonably large time window. The rationale is that if in such a time window + * we have not observed a high TLB use rate, it is likely that we won't observe + * it in the near future. In that case, once a time window expires we downsize + * the TLB to match the maximum use rate observed in the window. + * + * 3. Try to keep the maximum use rate in a time window in the 30-70% range, + * since in that range performance is likely near-optimal. Recall that the TLB + * is direct mapped, so we want the use rate to be low (or at least not too + * high), since otherwise we are likely to have a significant amount of + * conflict misses. + */ +static void tlb_mmu_resize_locked(CPUArchState *env, int mmu_idx) +{ + CPUTLBDesc *desc = &env->tlb_d[mmu_idx]; + size_t old_size = tlb_n_entries(env, mmu_idx); + size_t rate; + size_t new_size = old_size; + int64_t now = get_clock_realtime(); + int64_t window_len_ms = 100; + int64_t window_len_ns = window_len_ms * 1000 * 1000; + bool window_expired = now > desc->window.begin_ns + window_len_ns; + + if (desc->n_used_entries > desc->window.max_entries) { + desc->window.max_entries = desc->n_used_entries; + } + rate = desc->window.max_entries * 100 / old_size; + + if (rate > 70) { + new_size = MIN(old_size << 1, 1 << CPU_TLB_DYN_MAX_BITS); + } else if (rate < 30 && window_expired) { + size_t ceil = pow2ceil(desc->window.max_entries); + size_t expected_rate = desc->window.max_entries * 100 / ceil; + + /* + * Avoid undersizing when the max number of entries seen is just below + * a pow2. For instance, if max_entries == 1025, the expected use rate + * would be 1025/2048==50%. However, if max_entries == 1023, we'd get + * 1023/1024==99.9% use rate, so we'd likely end up doubling the size + * later. Thus, make sure that the expected use rate remains below 70%. + * (and since we double the size, that means the lowest rate we'd + * expect to get is 35%, which is still in the 30-70% range where + * we consider that the size is appropriate.) + */ + if (expected_rate > 70) { + ceil *= 2; + } + new_size = MAX(ceil, 1 << CPU_TLB_DYN_MIN_BITS); + } + + if (new_size == old_size) { + if (window_expired) { + tlb_window_reset(&desc->window, now, desc->n_used_entries); + } + return; + } + + g_free(env->tlb_table[mmu_idx]); + g_free(env->iotlb[mmu_idx]); + + tlb_window_reset(&desc->window, now, 0); + /* desc->n_used_entries is cleared by the caller */ + env->tlb_mask[mmu_idx] = (new_size - 1) << CPU_TLB_ENTRY_BITS; + env->tlb_table[mmu_idx] = g_try_new(CPUTLBEntry, new_size); + env->iotlb[mmu_idx] = g_try_new(CPUIOTLBEntry, new_size); + /* + * If the allocations fail, try smaller sizes. We just freed some + * memory, so going back to half of new_size has a good chance of working. + * Increased memory pressure elsewhere in the system might cause the + * allocations to fail though, so we progressively reduce the allocation + * size, aborting if we cannot even allocate the smallest TLB we support. + */ + while (env->tlb_table[mmu_idx] == NULL || env->iotlb[mmu_idx] == NULL) { + if (new_size == (1 << CPU_TLB_DYN_MIN_BITS)) { + error_report("%s: %s", __func__, strerror(errno)); + abort(); + } + new_size = MAX(new_size >> 1, 1 << CPU_TLB_DYN_MIN_BITS); + env->tlb_mask[mmu_idx] = (new_size - 1) << CPU_TLB_ENTRY_BITS; + + g_free(env->tlb_table[mmu_idx]); + g_free(env->iotlb[mmu_idx]); + env->tlb_table[mmu_idx] = g_try_new(CPUTLBEntry, new_size); + env->iotlb[mmu_idx] = g_try_new(CPUIOTLBEntry, new_size); + } +} + +static inline void tlb_table_flush_by_mmuidx(CPUArchState *env, int mmu_idx) +{ + tlb_mmu_resize_locked(env, mmu_idx); + memset(env->tlb_table[mmu_idx], -1, sizeof_tlb(env, mmu_idx)); + env->tlb_d[mmu_idx].n_used_entries = 0; +} + +static inline void tlb_n_used_entries_inc(CPUArchState *env, uintptr_t mmu_idx) +{ + env->tlb_d[mmu_idx].n_used_entries++; +} + +static inline void tlb_n_used_entries_dec(CPUArchState *env, uintptr_t mmu_idx) +{ + env->tlb_d[mmu_idx].n_used_entries--; +} + +#else /* !TCG_TARGET_IMPLEMENTS_DYN_TLB */ + +static inline void tlb_dyn_init(CPUArchState *env) +{ +} + +static inline void tlb_table_flush_by_mmuidx(CPUArchState *env, int mmu_idx) +{ + memset(env->tlb_table[mmu_idx], -1, sizeof(env->tlb_table[0])); +} + +static inline void tlb_n_used_entries_inc(CPUArchState *env, uintptr_t mmu_idx) +{ +} + +static inline void tlb_n_used_entries_dec(CPUArchState *env, uintptr_t mmu_idx) +{ +} +#endif /* TCG_TARGET_IMPLEMENTS_DYN_TLB */ + void tlb_init(CPUState *cpu) { CPUArchState *env = cpu->env_ptr; @@ -82,6 +263,8 @@ void tlb_init(CPUState *cpu) /* Ensure that cpu_reset performs a full flush. */ env->tlb_c.dirty = ALL_MMUIDX_BITS; + + tlb_dyn_init(env); } /* flush_all_helper: run fn across all cpus @@ -122,7 +305,7 @@ void tlb_flush_counts(size_t *pfull, size_t *ppart, size_t *pelide) static void tlb_flush_one_mmuidx_locked(CPUArchState *env, int mmu_idx) { - memset(env->tlb_table[mmu_idx], -1, sizeof(env->tlb_table[0])); + tlb_table_flush_by_mmuidx(env, mmu_idx); memset(env->tlb_v_table[mmu_idx], -1, sizeof(env->tlb_v_table[0])); env->tlb_d[mmu_idx].large_page_addr = -1; env->tlb_d[mmu_idx].large_page_mask = -1; @@ -225,12 +408,14 @@ static inline bool tlb_hit_page_anyprot(CPUTLBEntry *tlb_entry, } /* Called with tlb_c.lock held */ -static inline void tlb_flush_entry_locked(CPUTLBEntry *tlb_entry, +static inline bool tlb_flush_entry_locked(CPUTLBEntry *tlb_entry, target_ulong page) { if (tlb_hit_page_anyprot(tlb_entry, page)) { memset(tlb_entry, -1, sizeof(*tlb_entry)); + return true; } + return false; } /* Called with tlb_c.lock held */ @@ -241,7 +426,9 @@ static inline void tlb_flush_vtlb_page_locked(CPUArchState *env, int mmu_idx, assert_cpu_is_self(ENV_GET_CPU(env)); for (k = 0; k < CPU_VTLB_SIZE; k++) { - tlb_flush_entry_locked(&env->tlb_v_table[mmu_idx][k], page); + if (tlb_flush_entry_locked(&env->tlb_v_table[mmu_idx][k], page)) { + tlb_n_used_entries_dec(env, mmu_idx); + } } } @@ -258,7 +445,9 @@ static void tlb_flush_page_locked(CPUArchState *env, int midx, midx, lp_addr, lp_mask); tlb_flush_one_mmuidx_locked(env, midx); } else { - tlb_flush_entry_locked(tlb_entry(env, midx, page), page); + if (tlb_flush_entry_locked(tlb_entry(env, midx, page), page)) { + tlb_n_used_entries_dec(env, midx); + } tlb_flush_vtlb_page_locked(env, midx, page); } } @@ -435,8 +624,9 @@ void tlb_reset_dirty(CPUState *cpu, ram_addr_t start1, ram_addr_t length) qemu_spin_lock(&env->tlb_c.lock); for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { unsigned int i; + unsigned int n = tlb_n_entries(env, mmu_idx); - for (i = 0; i < CPU_TLB_SIZE; i++) { + for (i = 0; i < n; i++) { tlb_reset_dirty_range_locked(&env->tlb_table[mmu_idx][i], start1, length); } @@ -598,6 +788,7 @@ void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr, /* Evict the old entry into the victim tlb. */ copy_tlb_helper_locked(tv, te); env->iotlb_v[mmu_idx][vidx] = env->iotlb[mmu_idx][index]; + tlb_n_used_entries_dec(env, mmu_idx); } /* refill the tlb */ @@ -649,6 +840,7 @@ void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr, } copy_tlb_helper_locked(te, &tn); + tlb_n_used_entries_inc(env, mmu_idx); qemu_spin_unlock(&env->tlb_c.lock); }