| Message ID | 20190724010721.2146-1-richardw.yang@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] migration/postcopy: make PostcopyDiscardState a static variable | expand |
* Wei Yang (richardw.yang@linux.intel.com) wrote: > 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 <richardw.yang@linux.intel.com> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > --- > v2: > * make it a static variable, suggested by Dave > --- > migration/postcopy-ram.c | 70 +++++++++++++++++----------------------- > migration/postcopy-ram.h | 13 +++----- > migration/ram.c | 30 +++++++---------- > 3 files changed, 46 insertions(+), 67 deletions(-) > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 7b3e198538..cf2400b47e 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -1375,22 +1375,16 @@ 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; > } > > /** > @@ -1399,30 +1393,29 @@ 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; > } > } > > @@ -1431,24 +1424,21 @@ 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 e3a5cfd2d8..e3dde32155 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 ecd10baa43..7b7155a368 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -2761,12 +2761,9 @@ 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; > @@ -2787,7 +2784,7 @@ 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; > } > > @@ -2813,16 +2810,15 @@ 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; > } > @@ -2845,11 +2841,9 @@ 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; > @@ -2910,8 +2904,7 @@ 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 */ > @@ -2954,18 +2947,17 @@ 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; > } > > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Wei Yang (richardw.yang@linux.intel.com) wrote: > 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 <richardw.yang@linux.intel.com> Queued > > --- > v2: > * make it a static variable, suggested by Dave > --- > migration/postcopy-ram.c | 70 +++++++++++++++++----------------------- > migration/postcopy-ram.h | 13 +++----- > migration/ram.c | 30 +++++++---------- > 3 files changed, 46 insertions(+), 67 deletions(-) > > diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c > index 7b3e198538..cf2400b47e 100644 > --- a/migration/postcopy-ram.c > +++ b/migration/postcopy-ram.c > @@ -1375,22 +1375,16 @@ 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; > } > > /** > @@ -1399,30 +1393,29 @@ 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; > } > } > > @@ -1431,24 +1424,21 @@ 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 e3a5cfd2d8..e3dde32155 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 ecd10baa43..7b7155a368 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -2761,12 +2761,9 @@ 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; > @@ -2787,7 +2784,7 @@ 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; > } > > @@ -2813,16 +2810,15 @@ 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; > } > @@ -2845,11 +2841,9 @@ 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; > @@ -2910,8 +2904,7 @@ 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 */ > @@ -2954,18 +2947,17 @@ 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; > } > > -- > 2.17.1 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 7b3e198538..cf2400b47e 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -1375,22 +1375,16 @@ 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; } /** @@ -1399,30 +1393,29 @@ 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; } } @@ -1431,24 +1424,21 @@ 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 e3a5cfd2d8..e3dde32155 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 ecd10baa43..7b7155a368 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2761,12 +2761,9 @@ 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; @@ -2787,7 +2784,7 @@ 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; } @@ -2813,16 +2810,15 @@ 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; } @@ -2845,11 +2841,9 @@ 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; @@ -2910,8 +2904,7 @@ 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 */ @@ -2954,18 +2947,17 @@ 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; }
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 <richardw.yang@linux.intel.com> --- v2: * make it a static variable, suggested by Dave --- migration/postcopy-ram.c | 70 +++++++++++++++++----------------------- migration/postcopy-ram.h | 13 +++----- migration/ram.c | 30 +++++++---------- 3 files changed, 46 insertions(+), 67 deletions(-)