/** We need to remap the private views periodically. otherwise they would become very large.
Call within write lock.
*/
void REMAPPRIVATEVIEW() {
static unsigned startAt;
static unsigned long long lastRemap;
dbMutex.assertWriteLocked();
dbMutex._remapPrivateViewRequested = false;
assert( !commitJob.hasWritten() );
if( 0 ) {
log() << "TEMP remapprivateview disabled for testing - will eventually run oom in this mode if db bigger than ram" << endl;
return;
}
// we want to remap all private views about every 2 seconds. there could be ~1000 views so
// we do a little each pass; beyond the remap time, more significantly, there will be copy on write
// faults after remapping, so doing a little bit at a time will avoid big load spikes on
// remapping.
unsigned long long now = curTimeMicros64();
double fraction = (now-lastRemap)/20000000.0;
set<MongoFile*>& files = MongoFile::getAllFiles();
unsigned sz = files.size();
if( sz == 0 )
return;
unsigned ntodo = (unsigned) (sz * fraction);
if( ntodo < 1 ) ntodo = 1;
if( ntodo > sz ) ntodo = sz;
const set<MongoFile*>::iterator b = files.begin();
const set<MongoFile*>::iterator e = files.end();
set<MongoFile*>::iterator i = b;
// skip to our starting position
for( unsigned x = 0; x < startAt; x++ ) {
i++;
if( i == e ) i = b;
}
startAt = (startAt + ntodo) % sz; // mark where to start next time
for( unsigned x = 0; x < ntodo; x++ ) {
dassert( i != e );
if( (*i)->isMongoMMF() ) {
MongoMMF *mmf = (MongoMMF*) *i;
assert(mmf);
if( mmf->willNeedRemap() ) {
mmf->willNeedRemap() = false;
mmf->remapThePrivateView();
}
i++;
if( i == e ) i = b;
}
}
}
/** We need to remap the private views periodically. otherwise they would become very large.
Call within write lock.
*/
void _REMAPPRIVATEVIEW() {
// todo: Consider using ProcessInfo herein and watching for getResidentSize to drop. that could be a way
// to assure very good behavior here.
static unsigned startAt;
static unsigned long long lastRemap;
dbMutex.assertWriteLocked();
dbMutex._remapPrivateViewRequested = false;
assert( !commitJob.hasWritten() );
// we want to remap all private views about every 2 seconds. there could be ~1000 views so
// we do a little each pass; beyond the remap time, more significantly, there will be copy on write
// faults after remapping, so doing a little bit at a time will avoid big load spikes on
// remapping.
unsigned long long now = curTimeMicros64();
double fraction = (now-lastRemap)/2000000.0;
if( cmdLine.durOptions & CmdLine::DurAlwaysRemap )
fraction = 1;
lastRemap = now;
RWLockRecursive::Shared lk(MongoFile::mmmutex);
set<MongoFile*>& files = MongoFile::getAllFiles();
unsigned sz = files.size();
if( sz == 0 )
return;
{
// be careful not to use too much memory if the write rate is
// extremely high
double f = privateMapBytes / ((double)UncommittedBytesLimit);
if( f > fraction ) {
fraction = f;
}
privateMapBytes = 0;
}
unsigned ntodo = (unsigned) (sz * fraction);
if( ntodo < 1 ) ntodo = 1;
if( ntodo > sz ) ntodo = sz;
const set<MongoFile*>::iterator b = files.begin();
const set<MongoFile*>::iterator e = files.end();
set<MongoFile*>::iterator i = b;
// skip to our starting position
for( unsigned x = 0; x < startAt; x++ ) {
i++;
if( i == e ) i = b;
}
startAt = (startAt + ntodo) % sz; // mark where to start next time
for( unsigned x = 0; x < ntodo; x++ ) {
dassert( i != e );
if( (*i)->isMongoMMF() ) {
MongoMMF *mmf = (MongoMMF*) *i;
assert(mmf);
if( mmf->willNeedRemap() ) {
mmf->willNeedRemap() = false;
mmf->remapThePrivateView();
}
i++;
if( i == e ) i = b;
}
}
}
static void _REMAPPRIVATEVIEW() {
// todo: Consider using ProcessInfo herein and watching for getResidentSize to drop. that could be a way
// to assure very good behavior here.
static unsigned startAt;
static unsigned long long lastRemap;
LOG(4) << "journal REMAPPRIVATEVIEW" << endl;
verify( Lock::isW() );
verify( !commitJob.hasWritten() );
// we want to remap all private views about every 2 seconds. there could be ~1000 views so
// we do a little each pass; beyond the remap time, more significantly, there will be copy on write
// faults after remapping, so doing a little bit at a time will avoid big load spikes on
// remapping.
unsigned long long now = curTimeMicros64();
double fraction = (now-lastRemap)/2000000.0;
if( cmdLine.durOptions & CmdLine::DurAlwaysRemap )
fraction = 1;
lastRemap = now;
#if defined(_WIN32)
// Note that this negatively affects performance.
// We must grab the exclusive lock here because remapThePrivateView() on Windows needs
// to grab it as well, due to the lack of a non-atomic way to remap a memory mapped file.
// See SERVER-5723 for performance improvement.
// See SERVER-5680 to see why this code is necessary.
LockMongoFilesExclusive lk;
#else
LockMongoFilesShared lk;
#endif
set<MongoFile*>& files = MongoFile::getAllFiles();
unsigned sz = files.size();
if( sz == 0 )
return;
{
// be careful not to use too much memory if the write rate is
// extremely high
double f = privateMapBytes / ((double)UncommittedBytesLimit);
if( f > fraction ) {
fraction = f;
}
privateMapBytes = 0;
}
unsigned ntodo = (unsigned) (sz * fraction);
if( ntodo < 1 ) ntodo = 1;
if( ntodo > sz ) ntodo = sz;
const set<MongoFile*>::iterator b = files.begin();
const set<MongoFile*>::iterator e = files.end();
set<MongoFile*>::iterator i = b;
// skip to our starting position
for( unsigned x = 0; x < startAt; x++ ) {
i++;
if( i == e ) i = b;
}
unsigned startedAt = startAt;
startAt = (startAt + ntodo) % sz; // mark where to start next time
Timer t;
for( unsigned x = 0; x < ntodo; x++ ) {
dassert( i != e );
if( (*i)->isMongoMMF() ) {
MongoMMF *mmf = (MongoMMF*) *i;
verify(mmf);
if( mmf->willNeedRemap() ) {
mmf->willNeedRemap() = false;
mmf->remapThePrivateView();
}
i++;
if( i == e ) i = b;
}
}
LOG(2) << "journal REMAPPRIVATEVIEW done startedAt: " << startedAt << " n:" << ntodo << ' ' << t.millis() << "ms" << endl;
}