From 2d13bb6494c807bcf3f78af0e96c0b8615a94385 Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Wed, 14 Dec 2016 15:05:49 -0800 Subject: kernel/debug/debug_core.c: more properly delay for secondary CPUs We've got a delay loop waiting for secondary CPUs. That loop uses loops_per_jiffy. However, loops_per_jiffy doesn't actually mean how many tight loops make up a jiffy on all architectures. It is quite common to see things like this in the boot log: Calibrating delay loop (skipped), value calculated using timer frequency.. 48.00 BogoMIPS (lpj=24000) In my case I was seeing lots of cases where other CPUs timed out entering the debugger only to print their stack crawls shortly after the kdb> prompt was written. Elsewhere in kgdb we already use udelay(), so that should be safe enough to use to implement our timeout. We'll delay 1 ms for 1000 times, which should give us a full second of delay (just like the old code wanted) but allow us to notice that we're done every 1 ms. [akpm@linux-foundation.org: simplifications, per Daniel] Link: http://lkml.kernel.org/r/1477091361-2039-1-git-send-email-dianders@chromium.org Signed-off-by: Douglas Anderson Reviewed-by: Daniel Thompson Cc: Jason Wessel Cc: Brian Norris Cc: [4.0+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/debug/debug_core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 0874e2edd275..79517e5549f1 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -598,11 +598,11 @@ return_normal: /* * Wait for the other CPUs to be notified and be waiting for us: */ - time_left = loops_per_jiffy * HZ; + time_left = MSEC_PER_SEC; while (kgdb_do_roundup && --time_left && (atomic_read(&masters_in_kgdb) + atomic_read(&slaves_in_kgdb)) != online_cpus) - cpu_relax(); + udelay(1000); if (!time_left) pr_crit("Timed out waiting for secondary CPUs.\n"); -- cgit v1.3-14-g43fede From 314ff7851fc8ea66cbf48eaa93d8ebfb5ca084a9 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 3 Feb 2017 11:03:31 +0100 Subject: mm/vmacache, sched/headers: Introduce 'struct vmacache' and move it from to The header includes various vmacache related defines, which are arguably misplaced. Move them to mm_types.h and minimize the sched.h impact by putting all task vmacache state into a new 'struct vmacache' structure. No change in functionality. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- include/linux/mm_types.h | 12 ++++++++++++ include/linux/sched.h | 11 ++++------- include/linux/vmacache.h | 2 +- kernel/debug/debug_core.c | 4 ++-- mm/nommu.c | 2 +- mm/vmacache.c | 10 +++++----- 6 files changed, 25 insertions(+), 16 deletions(-) (limited to 'kernel/debug/debug_core.c') diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 4f6d440ad785..137797cd7b50 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -360,6 +360,18 @@ struct vm_area_struct { struct vm_userfaultfd_ctx vm_userfaultfd_ctx; }; +/* + * The per task VMA cache array: + */ +#define VMACACHE_BITS 2 +#define VMACACHE_SIZE (1U << VMACACHE_BITS) +#define VMACACHE_MASK (VMACACHE_SIZE - 1) + +struct vmacache { + u32 seqnum; + struct vm_area_struct *vmas[VMACACHE_SIZE]; +}; + struct core_thread { struct task_struct *task; struct core_thread *next; diff --git a/include/linux/sched.h b/include/linux/sched.h index 3f61baac928b..e87c97e1a947 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -134,10 +134,6 @@ struct blk_plug; struct filename; struct nameidata; -#define VMACACHE_BITS 2 -#define VMACACHE_SIZE (1U << VMACACHE_BITS) -#define VMACACHE_MASK (VMACACHE_SIZE - 1) - /* * These are the constant used to fake the fixed-point load-average * counting. Some notes: @@ -1550,9 +1546,10 @@ struct task_struct { #endif struct mm_struct *mm, *active_mm; - /* per-thread vma caching */ - u32 vmacache_seqnum; - struct vm_area_struct *vmacache[VMACACHE_SIZE]; + + /* Per-thread vma caching: */ + struct vmacache vmacache; + #if defined(SPLIT_RSS_COUNTING) struct task_rss_stat rss_stat; #endif diff --git a/include/linux/vmacache.h b/include/linux/vmacache.h index c3fa0fd43949..1081db987391 100644 --- a/include/linux/vmacache.h +++ b/include/linux/vmacache.h @@ -12,7 +12,7 @@ static inline void vmacache_flush(struct task_struct *tsk) { - memset(tsk->vmacache, 0, sizeof(tsk->vmacache)); + memset(tsk->vmacache.vmas, 0, sizeof(tsk->vmacache.vmas)); } extern void vmacache_flush_all(struct mm_struct *mm); diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index 79517e5549f1..a603ef28f70c 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -232,9 +232,9 @@ static void kgdb_flush_swbreak_addr(unsigned long addr) int i; for (i = 0; i < VMACACHE_SIZE; i++) { - if (!current->vmacache[i]) + if (!current->vmacache.vmas[i]) continue; - flush_cache_range(current->vmacache[i], + flush_cache_range(current->vmacache.vmas[i], addr, addr + BREAK_INSTR_SIZE); } } diff --git a/mm/nommu.c b/mm/nommu.c index fe9f4fa4a7a7..aae06e854552 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -757,7 +757,7 @@ static void delete_vma_from_mm(struct vm_area_struct *vma) mm->map_count--; for (i = 0; i < VMACACHE_SIZE; i++) { /* if the vma is cached, invalidate the entire cache */ - if (curr->vmacache[i] == vma) { + if (curr->vmacache.vmas[i] == vma) { vmacache_invalidate(mm); break; } diff --git a/mm/vmacache.c b/mm/vmacache.c index 035fdeb35b43..7c233f8e20ee 100644 --- a/mm/vmacache.c +++ b/mm/vmacache.c @@ -60,7 +60,7 @@ static inline bool vmacache_valid_mm(struct mm_struct *mm) void vmacache_update(unsigned long addr, struct vm_area_struct *newvma) { if (vmacache_valid_mm(newvma->vm_mm)) - current->vmacache[VMACACHE_HASH(addr)] = newvma; + current->vmacache.vmas[VMACACHE_HASH(addr)] = newvma; } static bool vmacache_valid(struct mm_struct *mm) @@ -71,12 +71,12 @@ static bool vmacache_valid(struct mm_struct *mm) return false; curr = current; - if (mm->vmacache_seqnum != curr->vmacache_seqnum) { + if (mm->vmacache_seqnum != curr->vmacache.seqnum) { /* * First attempt will always be invalid, initialize * the new cache for this task here. */ - curr->vmacache_seqnum = mm->vmacache_seqnum; + curr->vmacache.seqnum = mm->vmacache_seqnum; vmacache_flush(curr); return false; } @@ -93,7 +93,7 @@ struct vm_area_struct *vmacache_find(struct mm_struct *mm, unsigned long addr) return NULL; for (i = 0; i < VMACACHE_SIZE; i++) { - struct vm_area_struct *vma = current->vmacache[i]; + struct vm_area_struct *vma = current->vmacache.vmas[i]; if (!vma) continue; @@ -121,7 +121,7 @@ struct vm_area_struct *vmacache_find_exact(struct mm_struct *mm, return NULL; for (i = 0; i < VMACACHE_SIZE; i++) { - struct vm_area_struct *vma = current->vmacache[i]; + struct vm_area_struct *vma = current->vmacache.vmas[i]; if (vma && vma->vm_start == start && vma->vm_end == end) { count_vm_vmacache_event(VMACACHE_FIND_HITS); -- cgit v1.3-14-g43fede From 38b8d208a4544c9a26b10baec89b8a21042e5305 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 8 Feb 2017 18:51:31 +0100 Subject: sched/headers: Prepare for new header dependencies before moving code to We are going to move softlockup APIs out of , which will have to be picked up from other headers and a couple of .c files. already includes . Include the header in the files that are going to need it. Acked-by: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- arch/ia64/kernel/time.c | 1 + arch/ia64/kernel/uncached.c | 1 + arch/powerpc/kernel/swsusp_64.c | 1 + arch/x86/kernel/pvclock.c | 2 ++ arch/x86/xen/smp.c | 1 + drivers/ide/ide-taskfile.c | 1 + drivers/mtd/nand/nand_base.c | 1 + drivers/video/fbdev/nvidia/nv_accel.c | 2 ++ init/main.c | 1 + kernel/debug/debug_core.c | 1 + kernel/power/hibernate.c | 1 + kernel/power/snapshot.c | 1 + kernel/sched/clock.c | 1 + kernel/time/tick-sched.c | 1 + kernel/time/timekeeping.c | 1 + 15 files changed, 17 insertions(+) (limited to 'kernel/debug/debug_core.c') diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index faa116822c4c..144f9db7a876 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c index f3976da36721..583f7ff6b589 100644 --- a/arch/ia64/kernel/uncached.c +++ b/arch/ia64/kernel/uncached.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include diff --git a/arch/powerpc/kernel/swsusp_64.c b/arch/powerpc/kernel/swsusp_64.c index 0e899e47c325..51db012808f5 100644 --- a/arch/powerpc/kernel/swsusp_64.c +++ b/arch/powerpc/kernel/swsusp_64.c @@ -10,6 +10,7 @@ #include #include #include +#include void do_after_copyback(void) { diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c index 9e93fe5803b4..5c3f6d6a5078 100644 --- a/arch/x86/kernel/pvclock.c +++ b/arch/x86/kernel/pvclock.c @@ -21,6 +21,8 @@ #include #include #include +#include + #include #include diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 0dee6f59ea82..7ff2f1bfb7ec 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c index 247b9faccce1..4c0007cb74e3 100644 --- a/drivers/ide/ide-taskfile.c +++ b/drivers/ide/ide-taskfile.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 1492c12906f6..b0524f8accb6 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include diff --git a/drivers/video/fbdev/nvidia/nv_accel.c b/drivers/video/fbdev/nvidia/nv_accel.c index ad6472a894ea..7341fed63e35 100644 --- a/drivers/video/fbdev/nvidia/nv_accel.c +++ b/drivers/video/fbdev/nvidia/nv_accel.c @@ -48,6 +48,8 @@ */ #include +#include + #include "nv_type.h" #include "nv_proto.h" #include "nv_dma.h" diff --git a/init/main.c b/init/main.c index ae9f2008fb86..c891cfb8928f 100644 --- a/init/main.c +++ b/init/main.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index a603ef28f70c..65c0f1363788 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 86385af1080f..b8be5c803cdd 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index 905d5bbd595f..d79a38de425a 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/sched/clock.c b/kernel/sched/clock.c index dd7817cdbf58..a08795e21628 100644 --- a/kernel/sched/clock.c +++ b/kernel/sched/clock.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 0f411a4690a0..5e9e123b4321 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index fb564acee0f3..5b63a2102c29 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include -- cgit v1.3-14-g43fede