virtsnd_pcm_sg_num(9)

💅 virtsnd_pcm_sg_num 💅

okay so bestie, welcome to the virtsnd_pcm_sg_num page — that's the function name, and the manual it lives in is the Kernel API Manual, so you already know this is kernel-level business 🎀. This lil icon counts up how many scatter-gather elements you'd need to actually represent a buffer that came from vmalloc. Yes, it's as niche as it sounds and yes, it absolutely ate. ✨

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🌸 SYNOPSIS 🌸

int virtsnd_pcm_sg_num (u8 *data , unsigned int length );

that's the whole signature, no cap — hand it a buffer pointer and a length and it comes back with an int 🫶

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🦋 ARGUMENTS 🦋

• data — pointer to the vmalloc'ed buffer, like the main character of the operation 👑
• length — the buffer size, aka how much of it we're actually talking about 💖

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⭐ CONTEXT ⭐

Any context. literally any. she's flexible like that 💅 no special locking, no sleep restrictions mentioned, vibe check passed 🌈

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🎀 RETURN 🎀

The number of physically contiguous parts in the data. so like, if your vmalloc'ed buffer got scattered all over physical memory (which, bestie, it probably did — that's kind of vmalloc's whole thing 😭), this tells you how many pieces there are 🔥

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🧚 SEE ALSO 🧚

• Kernel file ./sound/virtio/virtio_pcm_msg.c
• struct virtio_pcm_msg(9)
• enum pcm_msg_sg_index(9)
• virtsnd_pcm_sg_from(9)
• virtsnd_pcm_msg_alloc(9)
• virtsnd_pcm_msg_free(9)
• virtsnd_pcm_msg_send(9)
• virtsnd_pcm_msg_pending_num(9)
• virtsnd_pcm_msg_complete(9)
• virtsnd_pcm_notify_cb(9)
• virtsnd_pcm_tx_notify_cb(9)
• virtsnd_pcm_rx_notify_cb(9)
• virtsnd_pcm_ctl_msg_alloc(9)

like, the whole friend group fr fr 🫶 go read them, iykyk 💜

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ngl this one's a supporting character in the virtio-snd saga, but every main character needs a bestie, so show her some respect 💀💖

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and that's the page!! source is ./sound/virtio, dated October 2026, and it's virtsnd_pcm_sg_num(9) all day every day — periodt. 🍓✨💅