From 33a03827d2a95c00d5294569d428354895378026 Mon Sep 17 00:00:00 2001 From: Torvald Riegel Date: Mon, 20 Feb 2012 20:56:42 +0000 Subject: [PATCH] libitm: Add missing undo-logging of RfW src regions in gl_wt memtransfer. libitm/ * method-gl.cc (gl_wt_dispatch::memtransfer_static): Add missing undo for RfW src. Optimize number of calls to gtm_thr. From-SVN: r184399 --- libitm/ChangeLog | 5 +++++ libitm/method-gl.cc | 19 +++++++++++-------- 2 files changed, 16 insertions(+), 8 deletions(-) diff --git a/libitm/ChangeLog b/libitm/ChangeLog index e0d94a1..75410f5 100644 --- a/libitm/ChangeLog +++ b/libitm/ChangeLog @@ -1,5 +1,10 @@ 2012-02-20 Torvald Riegel + * method-gl.cc (gl_wt_dispatch::memtransfer_static): Add missing undo + for RfW src. Optimize number of calls to gtm_thr. + +2012-02-20 Torvald Riegel + * beginend.cc (GTM::gtm_thread::begin_transaction): Move serial lock acquisition to ... * retry.cc (GTM::gtm_thread::decide_begin_dispatch): ... here. diff --git a/libitm/method-gl.cc b/libitm/method-gl.cc index d6d050d..4a18b62 100644 --- a/libitm/method-gl.cc +++ b/libitm/method-gl.cc @@ -85,9 +85,9 @@ static gl_mg o_gl_mg; class gl_wt_dispatch : public abi_dispatch { protected: - static void pre_write(const void *addr, size_t len) + static void pre_write(const void *addr, size_t len, + gtm_thread *tx = gtm_thr()) { - gtm_thread *tx = gtm_thr(); gtm_word v = tx->shared_state.load(memory_order_relaxed); if (unlikely(!gl_mg::is_locked(v))) { @@ -123,7 +123,7 @@ protected: tx->undolog.log(addr, len); } - static void validate() + static void validate(gtm_thread *tx = gtm_thr()) { // Check that snapshot is consistent. We expect the previous data load to // have acquire memory order, or be atomic and followed by an acquire @@ -137,7 +137,6 @@ protected: // or read an orec value that was written after the data had been written. // Either will allow us to detect inconsistent reads because it will have // a higher/different value. - gtm_thread *tx = gtm_thr(); gtm_word l = o_gl_mg.orec.load(memory_order_relaxed); if (l != tx->shared_state.load(memory_order_relaxed)) tx->restart(RESTART_VALIDATE_READ); @@ -198,9 +197,13 @@ public: static void memtransfer_static(void *dst, const void* src, size_t size, bool may_overlap, ls_modifier dst_mod, ls_modifier src_mod) { - if ((dst_mod != WaW && src_mod != RaW) - && (dst_mod != NONTXNAL || src_mod == RfW)) - pre_write(dst, size); + gtm_thread *tx = gtm_thr(); + if (dst_mod != WaW && dst_mod != NONTXNAL) + pre_write(dst, size, tx); + // We need at least undo-logging for an RfW src region because we might + // subsequently write there with WaW. + if (src_mod == RfW) + pre_write(src, size, tx); // FIXME We should use atomics here (see store()). Let's just hope that // memcpy/memmove are good enough. @@ -211,7 +214,7 @@ public: if (src_mod != RfW && src_mod != RaW && src_mod != NONTXNAL && dst_mod != WaW) - validate(); + validate(tx); } static void memset_static(void *dst, int c, size_t size, ls_modifier mod) -- 2.7.4