sqrt(n_layers) is only the best checkpoint step when mem size of checkpoints and mem size of layers are equal.
since layers require more memory than the single-tensor-checkpoint we use, the optimal values are compute different:
```
given: n, u, v
objective: minimize(a*u+b*v) where a*b=n, a>0, b>0
b=n/a
minimize(a*u+v*n/a)
diff(a*u+v*n/a, a) = u - (v*n/a)/a
diff(a*u+v*n/a, a) == 0
u - (v*n/a)/a == 0
u == v*n/(a*a)
u*a*a = v*n
a*a = v*n/u
a = sqrt(n*v/u)
```
this change results in more checkpoints, requiring less layers to store between checkpoints, overall improving memory usage.
dont use only sum as aggregation, because sum of softmax is always 1 -> finite differences should not work
instead use sum(log(soft_max()*(1-eps)+eps)); use eps to avoid log(0)
ggml_cross_entropy_loss: sums where not correctly added in workload of each thread
ggml_cross_entropy_loss_back: simplify backward process, reducing numerical issues
guard usage of exp f16 lookup in cross entropy by #define GGML_CROSS_ENTROPY_EXP_FP16
cross entropy loss is only used once during training, but it is quite sensitive to numerical errors introduced by exp-f16-lookup.
so exp-f16-lookup for cross entropy loss is disabled by default, trading better gradients for very slightly worse runtime performance.
It is now relative to Adam learning rate `alpha*sched`.
Before that it was relative to `sched` only.
`alpha` being the maximum learning rate and `sched` being a scaling parameter in [0..1]
reduces optimizer memory overhead from 7*modelsize to 2*modelsize.
additionally allows to optimize models with more than 2^31 parameters by replacing int with int64_t.
bumps training checkpoint file version, but old checkpoints can still be read.
new version with less tensors is saved.
* ggml : graph allocation in contexts
* allocate work buffer as a ggml_object in ggml_graph_compute_with_ctx
* llama.cpp : allocate graph in the context
* add GGML_PAD
---------
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
* add `--in-prefix-bos` to prefix BOS to user inputs; keep EOS
The BOS precedes the string specified by `--in-prefix`.
Model generated EOS is now kept in the context.
It provides a way to strictly following the prompt format used in
Llama-2-chat.
The EOS handling also benefits some existing finetunes that uses
EOS to mark the end of turn.
* examples/common: move input_prefix_bos to other bools
* metal: concurrently dispatch commands
Function `ggml_metal_graph_find_concurrency` will run and write
commands that can be issued concurrently to metal context `concur_list`
array, when `ggml_metal_graph_compute` is called for the first time.
* metal: don't call find_concurrency automatically.
* metal : code style changes
---------
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
* Another speed gain for Q4_0 and Q4_1 on Metal
* Have N_DST, etc., be template parameters
---------
Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>
* make rms_norm_eps a parameter
* add rms_norm_eps to command line
* fix baby llama, test-grad0
* use scientific notation for eps param in the help
ggml-ci
* makefile: correct deps for server
* server: tighten settings layout a little
* server: expose all currently configured generation params in UI
* server: expose remaining generation params, for the adventurous
* server: embetter mirostat fields
* llama, main : constrain sampling to grammar
* allow loading grammar from file
* fix whitespace errors
* handle & print parser errors
* add comments to grammar syntax and allow newlines where unambiguous
* add missing include
* support alternates in root rule
* fix bugs with empty token and EOS
* adjust JSON grammar
* remove swp file
* rewrite ternary expressions
Co-authored-by: Henri Vasserman <henv@hot.ee>
* use struct for grammar elements and add Unicode support
* add unicode escapes
* add inverse char ranges
* only sample full tokens (no peeking or truncation)
* llama : minor style changes
blindly applied in online editor - hopefully I didn't break something
* update help text
* add warning message if EOS is disabled
---------
Co-authored-by: Henri Vasserman <henv@hot.ee>
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
