On Fri, Jul 19, 2019 at 06:41:28PM +0100, Dr. David Alan Gilbert wrote: >* Wei Yang (richardw.y...@linux.intel.com) wrote: >> Even we need to do discard for each RAMBlock, we still can leverage the >> same memory space to store the information. >> >> By doing so, we avoid memory allocation and deallocation to the system >> and also avoid potential failure of memory allocation which breaks the >> migration. >> >> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com> >> --- >> migration/postcopy-ram.c | 16 +++++++--------- >> 1 file changed, 7 insertions(+), 9 deletions(-) >> >> diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c >> index 9faacacc9e..2e6b076bb7 100644 >> --- a/migration/postcopy-ram.c >> +++ b/migration/postcopy-ram.c >> @@ -1377,8 +1377,7 @@ 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. >> @@ -1386,13 +1385,14 @@ void >> postcopy_fault_thread_notify(MigrationIncomingState *mis) >> PostcopyDiscardState *postcopy_discard_send_init(MigrationState *ms, >> const char *name) >> { >> - PostcopyDiscardState *res = g_malloc0(sizeof(PostcopyDiscardState)); >> + static PostcopyDiscardState res = {0}; > >Do you think it would be better to make this a static at the top of >migration/postcopy-ram.c and then we could remove the pds parameters >from postcopy_discard_send_range and friends?
Just took a look into this one. One problem is not all its friends are in migration/postcopy-ram.c For example, postcopy_chunk_hostpages_pass() is in migration/ram.c. Which way do you prefer? >If there's only one pds then we don't need to pass the pointer around. > >Dave > >> - if (res) { >> - res->ramblock_name = name; >> - } >> + res.ramblock_name = name; >> + res.cur_entry = 0; >> + res.nsentwords = 0; >> + res.nsentcmds = 0; >> >> - return res; >> + return &res; >> } >> >> /** >> @@ -1449,8 +1449,6 @@ void postcopy_discard_send_finish(MigrationState *ms, >> PostcopyDiscardState *pds) >> >> trace_postcopy_discard_send_finish(pds->ramblock_name, pds->nsentwords, >> pds->nsentcmds); >> - >> - g_free(pds); >> } >> >> /* >> -- >> 2.17.1 >> >-- >Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK -- Wei Yang Help you, Help me