| Message ID | 20170116155113.21034-3-pbutsykin@virtuozzo.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
* Pavel Butsykin (pbutsykin@virtuozzo.com) wrote: > After the start of postcopy migration there are some non-dirty pages which have > already been migrated. These pages are no longer needed on the source vm so that > we can free them and it doen't hurt to complete the migration. > > Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> > --- > include/migration/migration.h | 1 + > migration/migration.c | 2 ++ > migration/ram.c | 25 +++++++++++++++++++++++++ > 3 files changed, 28 insertions(+) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index d7bd404365..0d9b81545c 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -279,6 +279,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms); > int ram_discard_range(MigrationIncomingState *mis, const char *block_name, > uint64_t start, size_t length); > int ram_postcopy_incoming_init(MigrationIncomingState *mis); > +void ram_postcopy_migrated_memory_discard(MigrationState *ms); > > /** > * @migrate_add_blocker - prevent migration from proceeding > diff --git a/migration/migration.c b/migration/migration.c > index 391db6f28b..20490ed020 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1662,6 +1662,8 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) > */ > qemu_savevm_send_ping(ms->to_dst_file, 4); > > + ram_postcopy_migrated_memory_discard(ms); > + Did you intend this to be selected based on your capability flag? > ret = qemu_file_get_error(ms->to_dst_file); > if (ret) { > error_report("postcopy_start: Migration stream errored"); > diff --git a/migration/ram.c b/migration/ram.c > index b0322a0b5c..8a6b614b0d 100644 > --- a/migration/ram.c > +++ b/migration/ram.c > @@ -1546,6 +1546,31 @@ void ram_debug_dump_bitmap(unsigned long *todump, bool expected) > > /* **** functions for postcopy ***** */ > > +void ram_postcopy_migrated_memory_discard(MigrationState *ms) > +{ > + struct RAMBlock *block; > + unsigned long *bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; > + > + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { > + unsigned long first = block->offset >> TARGET_PAGE_BITS; > + unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS); > + unsigned long run_start = find_next_zero_bit(bitmap, range, first); > + > + while (run_start < range) { > + unsigned long run_end = find_next_bit(bitmap, range, run_start + 1); > + uint8_t *addr = block->host + (run_start << TARGET_PAGE_BITS); > + size_t chunk_size = (run_end - run_start) << TARGET_PAGE_BITS; > + > + if (qemu_madvise(addr, chunk_size, QEMU_MADV_DONTNEED) < 0) { > + error_report("migrate: madvise DONTNEED failed %p %ld: %s", > + addr, chunk_size, strerror(errno)); > + } can you use your ram_discard_page here, it keeps all the use of madvise together. > + > + run_start = find_next_zero_bit(bitmap, range, run_end + 1); > + } > + } > +} Dave > /* > * Callback from postcopy_each_ram_send_discard for each RAMBlock > * Note: At this point the 'unsentmap' is the processed bitmap combined > -- > 2.11.0 > > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On 27.01.2017 14:39, Dr. David Alan Gilbert wrote: > * Pavel Butsykin (pbutsykin@virtuozzo.com) wrote: >> After the start of postcopy migration there are some non-dirty pages which have >> already been migrated. These pages are no longer needed on the source vm so that >> we can free them and it doen't hurt to complete the migration. >> >> Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> >> --- >> include/migration/migration.h | 1 + >> migration/migration.c | 2 ++ >> migration/ram.c | 25 +++++++++++++++++++++++++ >> 3 files changed, 28 insertions(+) >> >> diff --git a/include/migration/migration.h b/include/migration/migration.h >> index d7bd404365..0d9b81545c 100644 >> --- a/include/migration/migration.h >> +++ b/include/migration/migration.h >> @@ -279,6 +279,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms); >> int ram_discard_range(MigrationIncomingState *mis, const char *block_name, >> uint64_t start, size_t length); >> int ram_postcopy_incoming_init(MigrationIncomingState *mis); >> +void ram_postcopy_migrated_memory_discard(MigrationState *ms); >> >> /** >> * @migrate_add_blocker - prevent migration from proceeding >> diff --git a/migration/migration.c b/migration/migration.c >> index 391db6f28b..20490ed020 100644 >> --- a/migration/migration.c >> +++ b/migration/migration.c >> @@ -1662,6 +1662,8 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) >> */ >> qemu_savevm_send_ping(ms->to_dst_file, 4); >> >> + ram_postcopy_migrated_memory_discard(ms); >> + > > Did you intend this to be selected based on your capability flag? > I did, but apparently lost.. > >> ret = qemu_file_get_error(ms->to_dst_file); >> if (ret) { >> error_report("postcopy_start: Migration stream errored"); >> diff --git a/migration/ram.c b/migration/ram.c >> index b0322a0b5c..8a6b614b0d 100644 >> --- a/migration/ram.c >> +++ b/migration/ram.c >> @@ -1546,6 +1546,31 @@ void ram_debug_dump_bitmap(unsigned long *todump, bool expected) >> >> /* **** functions for postcopy ***** */ >> >> +void ram_postcopy_migrated_memory_discard(MigrationState *ms) >> +{ >> + struct RAMBlock *block; >> + unsigned long *bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; >> + >> + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { >> + unsigned long first = block->offset >> TARGET_PAGE_BITS; >> + unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS); >> + unsigned long run_start = find_next_zero_bit(bitmap, range, first); >> + >> + while (run_start < range) { >> + unsigned long run_end = find_next_bit(bitmap, range, run_start + 1); >> + uint8_t *addr = block->host + (run_start << TARGET_PAGE_BITS); >> + size_t chunk_size = (run_end - run_start) << TARGET_PAGE_BITS; >> + >> + if (qemu_madvise(addr, chunk_size, QEMU_MADV_DONTNEED) < 0) { >> + error_report("migrate: madvise DONTNEED failed %p %ld: %s", >> + addr, chunk_size, strerror(errno)); >> + } > > can you use your ram_discard_page here, it keeps all the use of madvise together. ok. >> + >> + run_start = find_next_zero_bit(bitmap, range, run_end + 1); >> + } >> + } >> +} > > Dave > >> /* >> * Callback from postcopy_each_ram_send_discard for each RAMBlock >> * Note: At this point the 'unsentmap' is the processed bitmap combined >> -- >> 2.11.0 >> >> > -- > Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK >
diff --git a/include/migration/migration.h b/include/migration/migration.h index d7bd404365..0d9b81545c 100644 --- a/include/migration/migration.h +++ b/include/migration/migration.h @@ -279,6 +279,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms); int ram_discard_range(MigrationIncomingState *mis, const char *block_name, uint64_t start, size_t length); int ram_postcopy_incoming_init(MigrationIncomingState *mis); +void ram_postcopy_migrated_memory_discard(MigrationState *ms); /** * @migrate_add_blocker - prevent migration from proceeding diff --git a/migration/migration.c b/migration/migration.c index 391db6f28b..20490ed020 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1662,6 +1662,8 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) */ qemu_savevm_send_ping(ms->to_dst_file, 4); + ram_postcopy_migrated_memory_discard(ms); + ret = qemu_file_get_error(ms->to_dst_file); if (ret) { error_report("postcopy_start: Migration stream errored"); diff --git a/migration/ram.c b/migration/ram.c index b0322a0b5c..8a6b614b0d 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1546,6 +1546,31 @@ void ram_debug_dump_bitmap(unsigned long *todump, bool expected) /* **** functions for postcopy ***** */ +void ram_postcopy_migrated_memory_discard(MigrationState *ms) +{ + struct RAMBlock *block; + unsigned long *bitmap = atomic_rcu_read(&migration_bitmap_rcu)->bmap; + + QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { + unsigned long first = block->offset >> TARGET_PAGE_BITS; + unsigned long range = first + (block->used_length >> TARGET_PAGE_BITS); + unsigned long run_start = find_next_zero_bit(bitmap, range, first); + + while (run_start < range) { + unsigned long run_end = find_next_bit(bitmap, range, run_start + 1); + uint8_t *addr = block->host + (run_start << TARGET_PAGE_BITS); + size_t chunk_size = (run_end - run_start) << TARGET_PAGE_BITS; + + if (qemu_madvise(addr, chunk_size, QEMU_MADV_DONTNEED) < 0) { + error_report("migrate: madvise DONTNEED failed %p %ld: %s", + addr, chunk_size, strerror(errno)); + } + + run_start = find_next_zero_bit(bitmap, range, run_end + 1); + } + } +} + /* * Callback from postcopy_each_ram_send_discard for each RAMBlock * Note: At this point the 'unsentmap' is the processed bitmap combined
After the start of postcopy migration there are some non-dirty pages which have already been migrated. These pages are no longer needed on the source vm so that we can free them and it doen't hurt to complete the migration. Signed-off-by: Pavel Butsykin <pbutsykin@virtuozzo.com> --- include/migration/migration.h | 1 + migration/migration.c | 2 ++ migration/ram.c | 25 +++++++++++++++++++++++++ 3 files changed, 28 insertions(+)