On Thu, Feb 15, 2024 at 7:40 PM Suren Baghdasaryan <surenb@xxxxxxxxxx> wrote: > > On Thu, Feb 15, 2024 at 4:14 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > On Wed, 14 Feb 2024 14:57:40 -0800 Sourav Panda <souravpanda@xxxxxxxxxx> wrote: > > > > > Adds two new per-node fields, namely nr_memmap and nr_memmap_boot, > > > to /sys/devices/system/node/nodeN/vmstat and a global Memmap field > > > to /proc/meminfo. This information can be used by users to see how > > > much memory is being used by per-page metadata, which can vary > > > depending on build configuration, machine architecture, and system > > > use. > > > > Would this information be available by the proposed memory > > allocation profiling? > > Well, not without jumping through the hoops. You would need to find > the places in the source code where all this matadata is allocated and > find the appropriate records inside /proc/allocinfo file. Another difference is that memory allocation profiling does not report memblock allocated memory, this patch reports the amount of per-page metadata allocated by the memblock allocator in addition to various paths that are used to allocate per-page metdata after the buddy allocator is initialized. Also, the memory profiling has page_ext overhead, so it is not practical to unconditionally enable it throughout the fleet. Pasha
