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Prepare for supporting single cpu affinity and non-asyn/await zero copy support. Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Changes Made: 1. Updated Cargo.toml: Changed libublk dependency to use the main branch from GitHub instead of crates.io to get the latest version with UBLK_DEV_F_SINGLE_CPU_AFFINITY support. 2. Added --multi-cpus-affinity flag: Added a new command-line option to GenAddArgs in src/args.rs:69 that allows users to opt-out of single CPU affinity. 3. Applied single CPU affinity by default: Modified the new_ublk_ctrl method in src/args.rs:206-211 to automatically apply UBLK_DEV_F_SINGLE_CPU_AFFINITY unless the --multi-cpus-affinity flag is specified. How it works: - Default behavior: All ublk devices now use single CPU affinity for improved performance - Opt-out option: Users can specify --multi-cpus-affinity to use the previous multi-CPU behavior - Universal application: The feature applies to all target types (loop, null, qcow2, compress, zoned) Signed-off-by: Ming Lei <tom.leiming@gmail.com>
1. Updated args.rs: Modified zero-copy validation to allow null targets alongside loop targets
2. Enhanced null.rs with zero-copy support:
- Added handle_queue_tag_async_null_zc() function that uses submit_io_cmd_with_auto_buf_reg()
with UBLK_AUTO_BUF_REG_FALLBACK flag
- Added handle_queue_tag_async_null() function for regular async operations
- Modified q_async_fn() to detect auto buffer registration support and select appropriate handler
- Added validation requiring --async-await when zero-copy is enabled for null targets
Also add sync zc:
1. Added q_sync_zc_fn() function:
- Creates auto buffer registration list for all queue depths
- Uses UblkQueue::submit_fetch_commands_with_auto_buf_reg() for initialization
- Uses UblkQueue::complete_io_cmd_with_auto_buf_reg() in the I/O handler
- Handles the shared data using Rc to satisfy borrow checker requirements
2. Updated queue handler logic:
- Added condition to use q_sync_zc_fn() when UBLK_F_AUTO_BUF_REG flag is set and async mode is not enabled
- Maintains existing behavior for async and regular sync modes
3. Removed async-await restriction:
- Zero-copy can now work in both synchronous and asynchronous modes
- Aligns with the new synchronous zero-copy implementation
Key Features:
- Zero-copy support: Null target now supports --zero-copy flag using UBLK_F_AUTO_BUF_REG
- Automatic buffer registration: Uses ublk_auto_buf_reg with fallback mode
- Validation: Requires --async-await flag when zero-copy is enabled
- Performance optimization: Eliminates buffer copies between kernel and userspace
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Changes Made to src/loop.rs 1. Added lo_handle_io_cmd_sync_zc() function (src/loop.rs:229-253): - Zero-copy version of the synchronous I/O command handler - Uses UblkQueue::complete_io_cmd_with_auto_buf_reg() instead of complete_io_cmd() - Uses __lo_make_io_sqe_zc() for zero-copy SQE generation instead of __lo_make_io_sqe() 2. Added q_zc_fn() function (src/loop.rs:281-301): - Synchronous zero-copy queue function using auto buffer registration - Creates auto buffer registration list for all queue depths - Uses UblkQueue::submit_fetch_commands_with_auto_buf_reg() for initialization - Uses shared Rc pattern to handle borrow checker requirements 3. Updated queue handler logic (src/loop.rs:435-447): - Added condition to use q_zc_fn() when UBLK_F_AUTO_BUF_REG flag is set and async mode is not enabled - Maintains existing behavior for async (q_a_fn()) and regular sync (q_fn()) modes 4. Removed async-await restriction (src/loop.rs:431-433): - Zero-copy can now work in both synchronous and asynchronous modes - Loop target now supports --zero-copy flag without requiring --async-await The implementation follows the same patterns as both the existing loop async zero-copy code and the null target's synchronous zero-copy implementation, ensuring consistency across the codebase. The loop target now supports zero-copy mode with --zero-copy flag in both synchronous and asynchronous modes, providing better performance through automatic buffer registration. Signed-off-by: Ming Lei <tom.leiming@gmail.com>
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