Revert "increase default context length to 4096 (#10364)"

This reverts commit 424f648632.

server/sched.go

@@ -58,7 +58,7 @@ var defaultModelsPerGPU = 3
 // Default automatic value for parallel setting
 // Model will still need to fit in VRAM.  If this setting won't fit
 // we'll back off down to 1 to try to get it to fit
-var defaultParallel = 2
+var defaultParallel = 4
 
 var ErrMaxQueue = errors.New("server busy, please try again.  maximum pending requests exceeded")
 
@@ -81,6 +81,10 @@ func InitScheduler(ctx context.Context) *Scheduler {
 
 // context must be canceled to decrement ref count and release the runner
 func (s *Scheduler) GetRunner(c context.Context, model *Model, opts api.Options, sessionDuration *api.Duration) (chan *runnerRef, chan error) {
+	if opts.NumCtx < 4 {
+		opts.NumCtx = 4
+	}
+
 	req := &LlmRequest{
 		ctx:             c,
 		model:           model,
@@ -110,11 +114,6 @@ func (s *Scheduler) Run(ctx context.Context) {
 	}()
 }
 
-const (
-	defaultContextLength  = 4096
-	smallGpuContextLength = 2048
-)
-
 func (s *Scheduler) processPending(ctx context.Context) {
 	for {
 		select {
@@ -167,17 +166,6 @@ func (s *Scheduler) processPending(ctx context.Context) {
 						gpus = s.getGpuFn()
 					}
 
-					if pending.origNumCtx == -1 {
-						if len(gpus) == 1 && gpus[0].Library != "cpu" && gpus[0].TotalMemory <= 4096*1024*1024 {
-							slog.Info("GPU is small, limiting default context window", "num_ctx", smallGpuContextLength)
-							pending.opts.NumCtx = smallGpuContextLength
-							pending.origNumCtx = smallGpuContextLength
-						} else {
-							pending.opts.NumCtx = defaultContextLength
-							pending.origNumCtx = defaultContextLength
-						}
-					}
-
 					if envconfig.MaxRunners() <= 0 {
 						// No user specified MaxRunners, so figure out what automatic setting to use
 						// If all GPUs have reliable free memory reporting, defaultModelsPerGPU * the number of GPUs