• [$] Fixing the TCMalloc regression with RSEQ operations

    From LWN.net@1337:1/100 to All on Mon Sep 7 15:45:06 2026
    [$] Fixing the TCMalloc regression with RSEQ operations

    Date:
    Mon, 07 Sep 2026 14:33:43 +0000

    Description:
    The restartable sequences feature is one of
    the stranger corners of the kernel's user-space interface; it provides a
    way for user space to carry out simple lockless operations and be informed
    if it is preempted over the course of an operation (and must, thus,
    restart). Work merged in the 6.19 release to improve the performance of restartable
    sequences broke the TCMalloc allocator ,
    which was relying on an undocumented (and unintended) kernel behavior.
    Now, Olivier Dion is proposing an
    addition to the restartable-sequences API that will bring TCMalloc back
    into the fold; it does not make the restartable-sequences API any less
    strange, though.

    ======================================================================
    Link to news story:
    https://lwn.net/Articles/1092555/


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