Re: [PATCH v3 04/16] xenctx: Add -2 (--two-pages) option to switch stack size to 8KiB

[Don Slutz <dslutz@verizon.com>]

On 11/12/13 10:31, Jan Beulich wrote:
>>>> On 11.11.13 at 19:15, Don Slutz <dslutz@verizon.com> wrote:
>> @@ -823,18 +826,20 @@ static void usage(void)
>>           kernel_start);
>>       printf("  -a, --all          display more registers\n");
>>       printf("  -C, --all-vcpus    print info for all vcpus\n");
>> +    printf("  -2, --two-pages    assume the kernel was compiled with 8KiB stacks.\n");
> I think it was IanC who had pointed out on the previous version
> that this would benefit from making fully flexible (i.e. also
> allowing larger stack sizes).
>
> Jan
>
Here is a fully flexible version:

 From 81f8af696816c02d13a6b29f6bb6ae8c4d99250d Mon Sep 17 00:00:00 2001
From: Don Slutz <Don@CloudSwitch.com>
Date: Mon, 2 Jul 2012 18:48:52 -0400
Subject: [PATCH] xenctx: Add -m (--multiple_pages) option to output larger
  stack

Important: This is the stack size to display not the configured
stack size.

Using pictures (for a 3 page configured system):

        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+
        |                  |
        |                  |
        |                  |
SP --> |                  |
        |                  |
        +------------------+

Display using "-m 1" since the used stack pages is 1.

        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+
        |                  |
SP --> |                  |
        |                  |
        |                  |
        |                  |
        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+

Display using "-m 2" since the used stack pages is 1.

        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
SP --> |                  |
        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+
        |                  |
        |                  |
        |                  |
        |                  |
        |                  |
        +------------------+

Display using "-m 3" since the used stack pages is 1.

Signed-off-by: Don Slutz <Don@CloudSwitch.com>
---
  tools/xentrace/xenctx.c | 11 ++++++++++-
  1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/xentrace/xenctx.c b/tools/xentrace/xenctx.c
index 841078d..2be5b08 100644
--- a/tools/xentrace/xenctx.c
+++ b/tools/xentrace/xenctx.c
@@ -35,6 +35,7 @@ static struct xenctx {
      int frame_ptrs;
      int stack_trace;
      int disp_all;
+    int multiple_pages;
      int all_vcpus;
      int self_paused;
      xc_dominfo_t dominfo;
@@ -650,6 +651,8 @@ static int print_stack(vcpu_guest_context_any_t *ctx, int vcpu, int width)

      stack_limit = ((stack_pointer(ctx) + XC_PAGE_SIZE)
                     & ~((guest_word_t) XC_PAGE_SIZE - 1));
+    if (xenctx.multiple_pages > 1)
+        stack_limit += (xenctx.multiple_pages - 1) * XC_PAGE_SIZE;
      printf("\n");
      printf("Stack:\n");
      for (i=1; i<5 && stack < stack_limit; i++) {
@@ -823,18 +826,21 @@ static void usage(void)
          kernel_start);
      printf("  -a, --all          display more registers\n");
      printf("  -C, --all-vcpus    print info for all vcpus\n");
+    printf("  -m PAGES, --multiple-pages=PAGES\n");
+    printf("                     assume the kernel was compiled with PAGES (default 1) of stacks.\n");
  }

  int main(int argc, char **argv)
  {
      int ch;
      int ret;
-    static const char *sopts = "fs:hak:SC";
+    static const char *sopts = "fs:hak:SCm:";
      static const struct option lopts[] = {
          {"stack-trace", 0, NULL, 'S'},
          {"symbol-table", 1, NULL, 's'},
          {"frame-pointers", 0, NULL, 'f'},
          {"kernel-start", 1, NULL, 'k'},
+        {"multiple-pages", 0, NULL, 'm'},
          {"all", 0, NULL, 'a'},
          {"all-vcpus", 0, NULL, 'C'},
          {"help", 0, NULL, 'h'},
@@ -858,6 +864,9 @@ int main(int argc, char **argv)
          case 'a':
              xenctx.disp_all = 1;
              break;
+        case 'm':
+            xenctx.multiple_pages = strtol(optarg, NULL, 0);
+            break;
          case 'C':
              xenctx.all_vcpus = 1;
              break;
-- 
1.7.11.7