* Wei Yang (richardw.y...@linux.intel.com) wrote: > 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.
But doesn't that just pass teh pds back to postcopy_discard_send_range which is in postcopy-ram ? Dave > 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 -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK