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| author | Phil Jones <philj56@gmail.com> | 2022-08-09 14:16:43 +0100 |
|---|---|---|
| committer | Phil Jones <philj56@gmail.com> | 2022-08-09 14:16:43 +0100 |
| commit | 64dfe36d347a2b329d8c0b6baa3ff782e66f0233 (patch) | |
| tree | 1a6eedd784ca1c7c186a98c4fec44745af2c6df0 | |
| parent | 6998cf1f0d6692255e09a46b5d59db08a7fd3d49 (diff) | |
Add note about hugepages to the readme.
| -rw-r--r-- | README.md | 49 |
1 files changed, 49 insertions, 0 deletions
@@ -268,3 +268,52 @@ The table below additionally includes `--late-keyboard-init` in the arguments. </tr> </tbody> </table> + +#### Bonus Round: Transparent HugePages + +It turns out that it's possible to speed up fullscreen windows somewhat with +some advanced memory tweaks. See [this Stack Overflow +question](https://stackoverflow.com/questions/73278608/can-mmaps-performance-be-improved-for-shared-memory) +if you want full details, but basically by setting +`/sys/kernel/mm/transparent_hugepage/shmem_enabled` to `advise`, we can tell +the kernel we're going to be working with large memory areas. This results in +fewer page faults when first allocating memory, speeding up tofi. + +Note that I don't recommend you play with this unless you know what you're +doing (I don't), but I've included it just in case, and to show that the +slowdown on large screens is partially due to factors beyond tofi's control. + +The table below shows the effects of additionally enabling hugepages from the +table above. The dmenu theme has been skipped, as the window it creates is too +small to benefit from them. The Raspberry Pi is also omitted, as it doesn't +support hugepages. + +<table> + <thead> + <tr> + <th colspan=2 rowspan=2/> + <th colspan=2> Theme </th> + </tr> + <tr> + <th> fullscreen </th> + <th> dos </th> + </tr> + </thead> + <tbody> + <tr> + <th rowspan=3> Machine </th> + <th> Ryzen 7 3700X <br> 2560px × 1440px </th> + <td align=right> 6.9ms ± 1.1ms </td> + <td align=right> 3.2ms ± 0.4ms </td> </tr> + <tr> + <th> Ryzen 5 5600U (AC) <br> 2880px × 1800px </th> + <td align=right> 7.9ms ± 1.2ms </td> + <td align=right> 3.4ms ± 1.0ms </td> + </tr> + <tr> + <th> Ryzen 5 5600U (battery) <br> 2880px × 1800px </th> + <td align=right> 13.7ms ± 0.9ms </td> + <td align=right> 5.6ms ± 0.8ms </td> + </tr> + </tbody> +</table> |