rpma_flush(3)

📦
version 1.3.0 · 3 versions
, in ubuntu noble

✨ rpma_flush — initiate the flush operation ✨

okay bestie, welcome to the RPMA Programmer's Manual, page rpma_flush(3) 💖 this one is short and sweet and honestly kinda iconic — it's the "okay we're DONE, push it through" of memory transfers. let's go 🫶

🌸 SYNOPSIS 🌸

#include <librpma.h>

struct rpma_conn;
struct rpma_mr_remote;
enum rpma_flush_type {
        RPMA_FLUSH_TYPE_PERSISTENT,
        RPMA_FLUSH_TYPE_VISIBILITY,
};

int rpma_flush(struct rpma_conn *conn,
                struct rpma_mr_remote *dst, size_t dst_offset,
                size_t len, enum rpma_flush_type type, int flags,
                const void *op_context);

💅 DESCRIPTION 💅

rpma_flush() initiates the flush operation — and what that means is you're finalizing a transfer of data to the remote memory. like, the data is out there, and now we make it official. periodt.

so there are possible types of rpma_flush() operation, and you gotta pick one:

  • RPMA_FLUSH_TYPE_PERSISTENT — flush data down to the persistent domain 🌈 (yes, all the way down, no half measures)
  • RPMA_FLUSH_TYPE_VISIBILITY — flush data deep enough to make it visible on the remote node 👀 (visible, not necessarily persisted — know the difference, iykyk)

then the attribute flags sets the completion notification indicator:

  • RPMA_F_COMPLETION_ON_ERROR — generate the completion on error
  • RPMA_F_COMPLETION_ALWAYS — generate the completion regardless of result of the operation.

and op_context? that lil baby gets returned in the wr_id field of the completion (struct ibv_wc). so you can match up your callback with your vibe. 💫

⭐ RETURN VALUE ⭐

the rpma_flush() function returns 0 on success or a negative error code on failure. no cap.

😭 ERRORS 😭

rpma_flush() can fail with the following errors — screenshot this, bestie:

  • RPMA_E_INVAL — conn or dst is NULL
  • RPMA_E_INVAL — unknown type value
  • RPMA_E_INVAL — flags are not set
  • RPMA_E_PROVIDER — ibv_post_send(3) failed
  • RPMA_E_NOSUPP — type is RPMA_FLUSH_TYPE_PERSISTENT and the direct write to pmem is not supported
not me getting RPMA_E_NOSUPP because persistent just isn't on the menu for this setup 💀 check your pmem support before you commit, fr fr.

🦋 SEE ALSO 🦋

and that's the whole page, angel 💖 this was the RPMA manual, dated 01 April 2024 — go forth and flush responsibly, you absolute main character 👑🎀

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