libnvme(2)

💖 libnvme — section 2 of the manual, bestie 💖

okay so you opened the libnvme manual (section 2, we're in the library docs now) and you landed on this little enum. it's giving "tiny but mighty". let's go 🦋

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✨ NAME ✨

enum nvme_cmbebs — this field indicates the controller memory buffer elasticity buffer size. yes that's a mouthful. we love her anyway 💅

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✨ SYNOPSIS ✨

enum nvme_cmbebs {
    NVME_CMBEBS_CMBSZU_SHIFT ,
    NVME_CMBEBS_RBB_SHIFT ,
    NVME_CMBEBS_CMBWBZ_SHIFT ,
    NVME_CMBEBS_CMBSZU_MASK ,
    NVME_CMBEBS_RBB_MASK ,
    NVME_CMBEBS_CMBWBZ_MASK ,
    NVME_CMBEBS_CMBSZU_B ,
    NVME_CMBEBS_CMBSZU_1K ,
    NVME_CMBEBS_CMBSZU_1M ,
    NVME_CMBEBS_CMBSZU_1G

};

like. look at her. ten little constants, all lined up, no drama. iconic 👑

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✨ Constants ✨

okay so here's the whole squad, one by one, no skips, periodt:

• NVME_CMBEBS_CMBSZU_SHIFT — the shift amount you use to pull out the CMB elasticity buffer size units 🌸
• NVME_CMBEBS_RBB_SHIFT — the shift amount you use to pull out the read bypass behavior 👀
• NVME_CMBEBS_CMBWBZ_SHIFT — the shift amount you use to pull out the CMB elasiticity buffer size base ✨
• NVME_CMBEBS_CMBSZU_MASK — the mask that gets you the CMB elasticity buffer size units 💅
• NVME_CMBEBS_RBB_MASK — the mask that gets you the read bypass behavior 🎀
• NVME_CMBEBS_CMBWBZ_MASK — the mask that gets you the CMB elasiticity buffer size base 🦋
• NVME_CMBEBS_CMBSZU_B — bytes granularity. the smallest unit, the little baby of the group, still valid tho 💖
• NVME_CMBEBS_CMBSZU_1K — 1 KiB granularity ⭐
• NVME_CMBEBS_CMBSZU_1M — 1 MiB granularity 🔥
• NVME_CMBEBS_CMBSZU_1G — 1 GiB granularity. main character energy for real 🫶

no cap: shifts and masks are a matching set here — the _SHIFT constants tell you how far to slide, the _MASK constants tell you what to keep, and the _CMBSZU_* constants are the granularity values themselves. that's the whole bit. that's the enum. 💀

and that's the vibe check, we're done, go mask some bits bestie 🌈

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sign-off time: this page is the enum nvme_cmbebs page inside the libnvme manual, and it's stamped July 2026 🎀 love that for her. mwah, bye 🧚💜