#4690 closed bug (fixed)
Writing to USB extremely slow
| Reported by: | koki | Owned by: | mmlr |
|---|---|---|---|
| Priority: | normal | Milestone: | R1 |
| Component: | Drivers/USB | Version: | R1/alpha1 |
| Keywords: | Cc: | imker@…, boobsd@… | |
| Blocked By: | Blocking: | ||
| Platform: | All |
Description
Using revision 33211, copying files to a USB thumbdrive (0930:6545 "Kingston" "DataTraveler 2.0" ver. 0100) is extremely slow.
The Tracker progress window shows completion of the copy operation very soon, but the thumbdrive LED keeps flashing for a long time, during which it is not possible to unmount the drive (I suppose indicating that copy operation is still taking place).
Here are the approximate times that it took Haiku to actually finish copying:
65MB of video files: 3 minutes 350MB ZIP: 8 minutes
Listdev output attached.
Not sure of the component selection, so feel free to change.
Attachments (1)
Change History (8)
by , 15 years ago
comment:1 by , 15 years ago
| Cc: | added |
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comment:2 by , 15 years ago
| Cc: | added |
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comment:3 by , 15 years ago
Read speeds should be reasonable (not optimal though) in hrev33503. I'm preparing a larger rework of page writing to also get write speeds to acceptable levels.
comment:4 by , 15 years ago
Write performance should be considerably better since hrev33507. Due to how the caches allocate pages it is possible though that due to physical page fragmentation performance degrades right down to the worst case scenario it was before. This should only be seen when saturating physical memory, i.e. when transferring large files so that the caches are exhausted. I'm investigating different allocation strategies and other possible optimizations to further optimize this though.
comment:5 by , 15 years ago
| Resolution: | → fixed |
|---|---|
| Status: | new → closed |
Both read and write performance should be reasonable on hrev33526 and up. It should also not degrade when running into low page situations anymore. Note that performance is still suboptimal compared to other systems due to various factors, like the fully synchronous transfers we do, the extra mappings we do and also due to how BFS works which isn't optimal for flash media. Still the performance should be OK for everyday usage. USB boot should also be improved quite a bit by those changes.
comment:6 by , 15 years ago
Results from (informal) testing by copying 450MB worth of video files on hrev33564:
When copying from the USB stick to HDD, files transfer is now much faster.
However, when copying from HDD to the USB stick, the Tracker progress bar flies by in 2-3 seconds, but the thumbdrive still keeps flashing a disproportionately long time (close to 3 minutes).
In contrast, on the same hardware, copying the very same files from HDD to the USB thumbdrive takes only 10-15 seconds in Windows and/or Ubuntu. I am not sure if this is the expected performance for Haiku at this stage, so just mentioning it as a point of reference. Let me know if you want me to provide any other info.
comment:7 by , 15 years ago
That's mostly OK. For one, the speed is limited due to the factors described above, and for the other, there's not much pressure. When there isn't much pressure, the system will gradually write back pages. If you instruct it to actually go forward using "sync" or unmounting/rebooting, it will push the changes through. There's provisions for write-through caches that could be used in this case to constantly flush changes, I'm not sure if that'd defeat some of the cache purpose though.
Listdev output