From 10da4a368992a5950abd07673ba8311fbbe667f5 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Thu, 25 Jul 2019 08:20:23 +0800 Subject: [PATCH] migration: extract ram_load_precopy After cleanup, it would be clear to audience there are two cases ram_load: * precopy * postcopy And it is not necessary to check postcopy_running on each iteration for precopy. Signed-off-by: Wei Yang Reviewed-by: Dr. David Alan Gilbert Message-Id: <20190725002023.2335-3-richardw.yang@linux.intel.com> Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 73 +++++++++++++++++++++++++++++++------------------ 1 file changed, 46 insertions(+), 27 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 6a75aedc91..a44e9c0abc 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -4318,40 +4318,26 @@ static void colo_flush_ram_cache(void) trace_colo_flush_ram_cache_end(); } -static int ram_load(QEMUFile *f, void *opaque, int version_id) +/** + * ram_load_precopy: load pages in precopy case + * + * Returns 0 for success or -errno in case of error + * + * Called in precopy mode by ram_load(). + * rcu_read_lock is taken prior to this being called. + * + * @f: QEMUFile where to send the data + */ +static int ram_load_precopy(QEMUFile *f) { - int flags = 0, ret = 0, invalid_flags = 0; - static uint64_t seq_iter; - int len = 0; - /* - * If system is running in postcopy mode, page inserts to host memory must - * be atomic - */ - bool postcopy_running = postcopy_is_running(); + int flags = 0, ret = 0, invalid_flags = 0, len = 0; /* ADVISE is earlier, it shows the source has the postcopy capability on */ bool postcopy_advised = postcopy_is_advised(); - - seq_iter++; - - if (version_id != 4) { - return -EINVAL; - } - if (!migrate_use_compression()) { invalid_flags |= RAM_SAVE_FLAG_COMPRESS_PAGE; } - /* This RCU critical section can be very long running. - * When RCU reclaims in the code start to become numerous, - * it will be necessary to reduce the granularity of this - * critical section. - */ - rcu_read_lock(); - if (postcopy_running) { - ret = ram_load_postcopy(f); - } - - while (!postcopy_running && !ret && !(flags & RAM_SAVE_FLAG_EOS)) { + while (!ret && !(flags & RAM_SAVE_FLAG_EOS)) { ram_addr_t addr, total_ram_bytes; void *host = NULL; uint8_t ch; @@ -4502,6 +4488,39 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) } } + return ret; +} + +static int ram_load(QEMUFile *f, void *opaque, int version_id) +{ + int ret = 0; + static uint64_t seq_iter; + /* + * If system is running in postcopy mode, page inserts to host memory must + * be atomic + */ + bool postcopy_running = postcopy_is_running(); + + seq_iter++; + + if (version_id != 4) { + return -EINVAL; + } + + /* + * This RCU critical section can be very long running. + * When RCU reclaims in the code start to become numerous, + * it will be necessary to reduce the granularity of this + * critical section. + */ + rcu_read_lock(); + + if (postcopy_running) { + ret = ram_load_postcopy(f); + } else { + ret = ram_load_precopy(f); + } + ret |= wait_for_decompress_done(); rcu_read_unlock(); trace_ram_load_complete(ret, seq_iter);