From: Andi Kleen <[email protected]> I was looking at large early boot allocations and noticed that since (1f12e32f x86/topology: Create logical package id) every 64bit system allocates a 128k array to convert logical package ids.
This happens because the array is sized to (MAX_LOCAL_APIC * u16) = 128k. This is a lot of waste especially for most systems which have one or two sockets. Use a dynamically allocated array of size logical_packages to map the logical and physical packages. [v2]: Decrease logical_packages when the last thread in a socket is removed. [v3]: Add more logic to keep logical and physical package IDs in synch. [v4]: Keep logical mapping static by using hybrid approach of a small logical to physical array and keeping logical cpu information in cpu_data. Signed-off-by: Andi Kleen <[email protected]> Signed-off-by: Prarit Bhargava <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: "H. Peter Anvin" <[email protected]> Cc: [email protected] Cc: Peter Zijlstra <[email protected]> Cc: Andi Kleen <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Piotr Luc <[email protected]> Cc: Kan Liang <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Stephane Eranian <[email protected]> Cc: Prarit Bhargava <[email protected]> Cc: Arvind Yadav <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: "Kirill A. Shutemov" <[email protected]> Cc: Tom Lendacky <[email protected]> Cc: Mathias Krause <[email protected]> Cc: Tim Chen <[email protected]> Cc: Vitaly Kuznetsov <[email protected]> --- arch/x86/include/asm/processor.h | 4 +- arch/x86/kernel/smpboot.c | 86 +++++++++++++++++++--------------------- 2 files changed, 43 insertions(+), 47 deletions(-) diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index b390ff76e58f..f4ab1edf4e24 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -124,8 +124,10 @@ struct cpuinfo_x86 { u16 booted_cores; /* Physical processor id: */ u16 phys_proc_id; - /* Logical processor id: */ + /* Logical processor (package) id: */ u16 logical_proc_id; + /* Physical package ID */ + u16 phys_pkg_id; /* Core id: */ u16 cpu_core_id; /* Index into per_cpu list: */ diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index ad59edd84de7..ca615bc94e82 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -99,12 +99,10 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map); DEFINE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); -/* Logical package management. We might want to allocate that dynamically */ -static int *physical_to_logical_pkg __read_mostly; -static unsigned long *physical_package_map __read_mostly;; -static unsigned int max_physical_pkg_id __read_mostly; +/* Logical package management.*/ unsigned int __max_logical_packages __read_mostly; EXPORT_SYMBOL(__max_logical_packages); +static u16 *logical_to_physical_pkg_map; static unsigned int logical_packages __read_mostly; /* Maximum number of SMT threads on any online core */ @@ -278,6 +276,23 @@ static void notrace start_secondary(void *unused) cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); } +/** + * topology_phys_to_logical_pkg - Map a physical package id to a logical + * + * Returns logical package id or -1 if not found + */ +int topology_phys_to_logical_pkg(unsigned int phys_pkg) +{ + int log_pkg; + + for (log_pkg = 0; log_pkg < logical_packages; log_pkg++) + if (logical_to_physical_pkg_map[log_pkg] == phys_pkg) + return log_pkg; + + return -1; +} +EXPORT_SYMBOL(topology_phys_to_logical_pkg); + /** * topology_update_package_map - Update the physical to logical package map * @pkg: The physical package id as retrieved via CPUID @@ -285,17 +300,11 @@ static void notrace start_secondary(void *unused) */ int topology_update_package_map(unsigned int pkg, unsigned int cpu) { - unsigned int new; - - /* Called from early boot ? */ - if (!physical_package_map) - return 0; - - if (pkg >= max_physical_pkg_id) - return -EINVAL; + int new; + u16 *ltp_pkg_map_new; - /* Set the logical package id */ - if (test_and_set_bit(pkg, physical_package_map)) + new = topology_phys_to_logical_pkg(pkg); + if (new >= 0) goto found; if (logical_packages >= __max_logical_packages) { @@ -305,34 +314,30 @@ int topology_update_package_map(unsigned int pkg, unsigned int cpu) } new = logical_packages++; - if (new != pkg) { - pr_info("CPU %u Converting physical %u to logical package %u\n", - cpu, pkg, new); + + /* Allocate and copy a new array */ + ltp_pkg_map_new = kmalloc(logical_packages * sizeof(u16), GFP_KERNEL); + BUG_ON(!ltp_pkg_map_new); + if (logical_to_physical_pkg_map) { + memcpy(ltp_pkg_map_new, logical_to_physical_pkg_map, + logical_packages * sizeof(u16)); + kfree(logical_to_physical_pkg_map); } - physical_to_logical_pkg[pkg] = new; + logical_to_physical_pkg_map = ltp_pkg_map_new; + logical_to_physical_pkg_map[new] = pkg; + if (pkg != new) + pr_info("CPU %u Converting physical %u to logical package %u\n", + cpu, pkg, new); found: - cpu_data(cpu).logical_proc_id = physical_to_logical_pkg[pkg]; + cpu_data(cpu).phys_pkg_id = pkg; + cpu_data(cpu).logical_proc_id = new; return 0; } -/** - * topology_phys_to_logical_pkg - Map a physical package id to a logical - * - * Returns logical package id or -1 if not found - */ -int topology_phys_to_logical_pkg(unsigned int phys_pkg) -{ - if (phys_pkg >= max_physical_pkg_id) - return -1; - return physical_to_logical_pkg[phys_pkg]; -} -EXPORT_SYMBOL(topology_phys_to_logical_pkg); - static void __init smp_init_package_map(struct cpuinfo_x86 *c, unsigned int cpu) { unsigned int ncpus; - size_t size; /* * Today neither Intel nor AMD support heterogenous systems. That @@ -363,21 +368,10 @@ static void __init smp_init_package_map(struct cpuinfo_x86 *c, unsigned int cpu) } __max_logical_packages = DIV_ROUND_UP(total_cpus, ncpus); - logical_packages = 0; - - /* - * Possibly larger than what we need as the number of apic ids per - * package can be smaller than the actual used apic ids. - */ - max_physical_pkg_id = DIV_ROUND_UP(MAX_LOCAL_APIC, ncpus); - size = max_physical_pkg_id * sizeof(unsigned int); - physical_to_logical_pkg = kmalloc(size, GFP_KERNEL); - memset(physical_to_logical_pkg, 0xff, size); - size = BITS_TO_LONGS(max_physical_pkg_id) * sizeof(unsigned long); - physical_package_map = kzalloc(size, GFP_KERNEL); - pr_info("Max logical packages: %u\n", __max_logical_packages); + logical_packages = 0; + topology_update_package_map(c->phys_proc_id, cpu); } -- 2.15.0.rc0.39.g2f0e14e64
