From 810cf2bbd4c5c1417bda8bec49caf0ababc22860 Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Wed, 24 Jul 2019 09:07:21 +0800 Subject: migration/postcopy: make PostcopyDiscardState a static variable In postcopy-ram.c, we provide three functions to discard certain RAMBlock range: * postcopy_discard_send_init() * postcopy_discard_send_range() * postcopy_discard_send_finish() Currently, we allocate/deallocate PostcopyDiscardState for each RAMBlock on sending discard information to destination. This is not necessary and the same data area could be reused for each RAMBlock. This patch defines PostcopyDiscardState a static variable. By doing so: 1) avoid memory allocation and deallocation to the system 2) avoid potential failure of memory allocation 3) hide some details for their users Signed-off-by: Wei Yang Message-Id: <20190724010721.2146-1-richardw.yang@linux.intel.com> Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Dr. David Alan Gilbert --- migration/postcopy-ram.c | 70 +++++++++++++++++++++--------------------------- migration/postcopy-ram.h | 13 ++++----- migration/ram.c | 30 ++++++++------------- 3 files changed, 46 insertions(+), 67 deletions(-) (limited to 'migration') diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 9faacacc9e..2cb1a69752 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -1377,22 +1377,16 @@ void postcopy_fault_thread_notify(MigrationIncomingState *mis) * asking to discard individual ranges. * * @ms: The current migration state. - * @offset: the bitmap offset of the named RAMBlock in the migration - * bitmap. + * @offset: the bitmap offset of the named RAMBlock in the migration bitmap. * @name: RAMBlock that discards will operate on. - * - * returns: a new PDS. */ -PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms, - const char *name) +static PostcopyDiscardState pds = {0}; +void postcopy_discard_send_init(MigrationState *ms, const char *name) { - PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState)); - - if (res) { - res->ramblock_name = name; - } - - return res; + pds.ramblock_name = name; + pds.cur_entry = 0; + pds.nsentwords = 0; + pds.nsentcmds = 0; } /** @@ -1401,30 +1395,29 @@ PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms, * be sent later. * * @ms: Current migration state. - * @pds: Structure initialised by postcopy_discard_send_init(). * @start,@length: a range of pages in the migration bitmap in the * RAM block passed to postcopy_discard_send_init() (length=1 is one page) */ -void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds, - unsigned long start, unsigned long length) +void postcopy_discard_send_range(MigrationState *ms, unsigned long start, + unsigned long length) { size_t tp_size = qemu_target_page_size(); /* Convert to byte offsets within the RAM block */ - pds->start_list[pds->cur_entry] = start * tp_size; - pds->length_list[pds->cur_entry] = length * tp_size; - trace_postcopy_discard_send_range(pds->ramblock_name, start, length); - pds->cur_entry++; - pds->nsentwords++; + pds.start_list[pds.cur_entry] = start * tp_size; + pds.length_list[pds.cur_entry] = length * tp_size; + trace_postcopy_discard_send_range(pds.ramblock_name, start, length); + pds.cur_entry++; + pds.nsentwords++; - if (pds->cur_entry == MAX_DISCARDS_PER_COMMAND) { + if (pds.cur_entry == MAX_DISCARDS_PER_COMMAND) { /* Full set, ship it! */ qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file, - pds->ramblock_name, - pds->cur_entry, - pds->start_list, - pds->length_list); - pds->nsentcmds++; - pds->cur_entry = 0; + pds.ramblock_name, + pds.cur_entry, + pds.start_list, + pds.length_list); + pds.nsentcmds++; + pds.cur_entry = 0; } } @@ -1433,24 +1426,21 @@ void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds, * bitmap code. Sends any outstanding discard messages, frees the PDS * * @ms: Current migration state. - * @pds: Structure initialised by postcopy_discard_send_init(). */ -void postcopy_discard_send_finish(MigrationState *ms, PostcopyDiscardState *pds) +void postcopy_discard_send_finish(MigrationState *ms) { /* Anything unsent? */ - if (pds->cur_entry) { + if (pds.cur_entry) { qemu_savevm_send_postcopy_ram_discard(ms->to_dst_file, - pds->ramblock_name, - pds->cur_entry, - pds->start_list, - pds->length_list); - pds->nsentcmds++; + pds.ramblock_name, + pds.cur_entry, + pds.start_list, + pds.length_list); + pds.nsentcmds++; } - trace_postcopy_discard_send_finish(pds->ramblock_name, pds->nsentwords, - pds->nsentcmds); - - g_free(pds); + trace_postcopy_discard_send_finish(pds.ramblock_name, pds.nsentwords, + pds.nsentcmds); } /* diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h index 9d55536fd1..9c8bd2bae0 100644 --- a/migration/postcopy-ram.h +++ b/migration/postcopy-ram.h @@ -43,10 +43,8 @@ int postcopy_ram_prepare_discard(MigrationIncomingState *mis); /* * Called at the start of each RAMBlock by the bitmap code. - * Returns a new PDS */ -PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms, - const char *name); +void postcopy_discard_send_init(MigrationState *ms, const char *name); /* * Called by the bitmap code for each chunk to discard. @@ -55,15 +53,14 @@ PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms, * @start,@length: a range of pages in the migration bitmap in the * RAM block passed to postcopy_discard_send_init() (length=1 is one page) */ -void postcopy_discard_send_range(MigrationState *ms, PostcopyDiscardState *pds, - unsigned long start, unsigned long length); +void postcopy_discard_send_range(MigrationState *ms, unsigned long start, + unsigned long length); /* * Called at the end of each RAMBlock by the bitmap code. - * Sends any outstanding discard messages, frees the PDS. + * Sends any outstanding discard messages. */ -void postcopy_discard_send_finish(MigrationState *ms, - PostcopyDiscardState *pds); +void postcopy_discard_send_finish(MigrationState *ms); /* * Place a page (from) at (host) efficiently diff --git a/migration/ram.c b/migration/ram.c index a44e9c0abc..f428639af5 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2850,12 +2850,9 @@ void ram_postcopy_migrated_memory_release(MigrationState *ms) * with the dirtymap; so a '1' means it's either dirty or unsent. * * @ms: current migration state - * @pds: state for postcopy * @block: RAMBlock to discard */ -static int postcopy_send_discard_bm_ram(MigrationState *ms, - PostcopyDiscardState *pds, - RAMBlock *block) +static int postcopy_send_discard_bm_ram(MigrationState *ms, RAMBlock *block) { unsigned long end = block->used_length >> TARGET_PAGE_BITS; unsigned long current; @@ -2876,7 +2873,7 @@ static int postcopy_send_discard_bm_ram(MigrationState *ms, } else { discard_length = zero - one; } - postcopy_discard_send_range(ms, pds, one, discard_length); + postcopy_discard_send_range(ms, one, discard_length); current = one + discard_length; } @@ -2902,16 +2899,15 @@ static int postcopy_each_ram_send_discard(MigrationState *ms) int ret; RAMBLOCK_FOREACH_NOT_IGNORED(block) { - PostcopyDiscardState *pds = - postcopy_discard_send_init(ms, block->idstr); + postcopy_discard_send_init(ms, block->idstr); /* * Postcopy sends chunks of bitmap over the wire, but it * just needs indexes at this point, avoids it having * target page specific code. */ - ret = postcopy_send_discard_bm_ram(ms, pds, block); - postcopy_discard_send_finish(ms, pds); + ret = postcopy_send_discard_bm_ram(ms, block); + postcopy_discard_send_finish(ms); if (ret) { return ret; } @@ -2934,11 +2930,9 @@ static int postcopy_each_ram_send_discard(MigrationState *ms) * @unsent_pass: if true we need to canonicalize partially unsent host pages * otherwise we need to canonicalize partially dirty host pages * @block: block that contains the page we want to canonicalize - * @pds: state for postcopy */ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, - RAMBlock *block, - PostcopyDiscardState *pds) + RAMBlock *block) { RAMState *rs = ram_state; unsigned long *bitmap = block->bmap; @@ -3018,8 +3012,7 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, * (any partially sent pages were already discarded * by the previous unsent_pass) */ - postcopy_discard_send_range(ms, pds, fixup_start_addr, - host_ratio); + postcopy_discard_send_range(ms, fixup_start_addr, host_ratio); } /* Clean up the bitmap */ @@ -3062,18 +3055,17 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass, */ static int postcopy_chunk_hostpages(MigrationState *ms, RAMBlock *block) { - PostcopyDiscardState *pds = - postcopy_discard_send_init(ms, block->idstr); + postcopy_discard_send_init(ms, block->idstr); /* First pass: Discard all partially sent host pages */ - postcopy_chunk_hostpages_pass(ms, true, block, pds); + postcopy_chunk_hostpages_pass(ms, true, block); /* * Second pass: Ensure that all partially dirty host pages are made * fully dirty. */ - postcopy_chunk_hostpages_pass(ms, false, block, pds); + postcopy_chunk_hostpages_pass(ms, false, block); - postcopy_discard_send_finish(ms, pds); + postcopy_discard_send_finish(ms); return 0; } -- cgit v1.2.3-55-g7522