NVMe driver: add v6.8 benchmarks

Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com>
[ Replaced MathJax with simple MathML -- let's be modern. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: metaspace

src/NVMe-driver.md

@@ -7,7 +7,7 @@ implementation language for high performance device drivers.
 
 
 The Linux Rust NVMe driver lives
-[here](https://github.com/metaspace/linux/tree/nvme). This branch is routinely
+[here](https://github.com/metaspace/linux/tree/rnvme). This branch is routinely
 rebased on upstream Linux releases. Please be aware that the `nvme` branch is
 force pushed without notice. The version based on the deprecated `rust` branch
 is available [here](https://github.com/metaspace/linux/tree/nvme-rust).
@@ -23,6 +23,41 @@ The driver is not currently suitable for general use.
    [slides](https://lpc.events/event/16/contributions/1180/attachments/1017/1961/deck.pdf)
    and [video](https://lpc.events/event/16/contributions/1180/attachments/1017/2249/go)
 
+## 6.8 Rebase Performance ([`rnvme-v6.8`](https://github.com/metaspace/linux/tree/rnvme-v6.8))
+
+### Setup
+
+ - AMD Ryzen 5 7600
+ - 32 GB 4800 MT/s DDR5 on one channel
+ - 1x Samsung 990 Pro 1TB (PCIe 4.0 x4 16 GT/S)
+ - NixOS 23.11
+
+### Results
+
+- 40 samples
+- Difference of means modeled with t-distribution
+- P95 confidence intervals
+
+![](rnvme/nvme-v6.8-absolute.svg)
+
+![](rnvme/nvme-v6.8-relative.svg)
+
+The graph shows
+    <math>
+        <mfrac>
+            <mrow>
+                <mi>R</mi>
+                <mo>-</mo>
+                <mi>C</mi>
+            </mrow>
+            <mrow>
+                <mi>C</mi>
+            </mrow>
+        </mfrac>
+    </math>
+where C is IO/s for the C driver and R is IO/s for the Rust driver. Thus, negative
+means the C driver is faster while positive means the Rust driver is faster.
+
 ## 6.7 Rebase Performance ([`nvme-6.7`](https://github.com/metaspace/linux/tree/nvme-6.7))
 
 ### Setup