Re: [PATCH v5 4/5] perf script: Add --lazy-load-symbols for lazy symbol loading

[sashiko-bot@kernel.org]

> From: Alireza Haghdoost <haghdoost@uber.com>
> 
> perf script eagerly materializes eligible symbols from every DSO
> encountered in samples and keeps them in an rb-tree until exit.
> Most of those symbols are never sampled. On a large profile this
> turns symbol loading into the main memory cost of perf script, and in a
> memory-constrained cgroup into an OOM kill.
> 
> This patch adds --lazy-load-symbols for userspace ELF DSOs. It builds a
> compact address-sorted index and materializes ordinary struct symbols on
> demand. Names are read and demangled from the exact ELF source through
> the existing DSO data cache; resolved symbols are then inserted into the
> DSO's existing rb-tree.
> 
> struct symbol is unchanged. Each index entry holds only the address range,
> [ ... ]
> entire lazy index and detaches it from the DSO. A detached index remains
> alive until its last reader finishes, ensuring that no symbols are added
> after the name-sorted array is built.
> 
> Signed-off-by: Alireza Haghdoost <haghdoost@uber.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20261005-perf-symbol-memory-send-v5-0-165dceb2b049@uber.com?part=4