Add TdsKVBackend storage driver with zero-copy O_DIRECT and 4KB bounce-buffering. - #948
Open
copybara-service[bot] wants to merge 1 commit into
Open
copybara-service[bot] wants to merge 1 commit into
copybara-service[bot] wants to merge 1 commit into
Conversation
|
Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA). View this failed invocation of the CLA check for more information. For the most up to date status, view the checks section at the bottom of the pull request. |
…e-buffering. Standard buffered POSIX file I/O copies KV cache blocks through the Linux kernel page cache, incurring CPU `memcpy` overhead and host RAM page-cache bloat on high-throughput storage tiers such as Lustre, NFS, and NVMe SSDs. Implement `tpu_raiden::kv_cache::backends::storage::TdsKVBackend` (`tkv::backends::storage::TdsKVBackend`) inheriting from `KVBackend`. For 4KB-aligned, registered Host DRAM slices (`HostBufferDescriptor`), execute zero-copy `O_DIRECT` transfers directly between storage and host memory (`direct_ops`). For unaligned buffer addresses, slice lengths, or file offsets, automatically route through a 4KB-aligned bounce-buffer engine (`bounced_ops`) while preserving exact logical file sizes via `ftruncate`. Support `lustre://` and `nfs://` URI resolution, configurable options (`TdsBackendOptions::FromProperties`), and optional Lustre OST striping (`LL_IOC_LOV_SETSTRIPE`). PiperOrigin-RevId: 983561034
copybara-service
Bot
force-pushed
the
test_983561034
branch
from
September 21, 2026 15:12
e8d41bb to
0d5aa8a
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Add TdsKVBackend storage driver with zero-copy O_DIRECT and 4KB bounce-buffering.
Standard buffered POSIX file I/O copies KV cache blocks through the Linux kernel page cache, incurring CPU
memcpyoverhead and host RAM page-cache bloat on high-throughput storage tiers such as Lustre, NFS, and NVMe SSDs.Implement
tpu_raiden::kv_cache::backends::storage::TdsKVBackend(tkv::backends::storage::TdsKVBackend) inheriting fromKVBackend. For 4KB-aligned, registered Host DRAM slices (HostBufferDescriptor), execute zero-copyO_DIRECTtransfers directly between storage and host memory (direct_ops). For unaligned buffer addresses, slice lengths, or file offsets, automatically route through a 4KB-aligned bounce-buffer engine (bounced_ops) while preserving exact logical file sizes viaftruncate. Supportlustre://andnfs://URI resolution, configurable options (TdsBackendOptions::FromProperties), and optional Lustre OST striping (LL_IOC_LOV_SETSTRIPE).