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Commit 3795e1616f16905889761536cdc266ebc51855e5

Authored by Jesper Juhl
Committed by Linus Torvalds
1 parent a547dfe956
Exists in master and in 7 other branches imx_3.0.35_4.1.0, imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga, smarc-l5.0.0_1.0.0-ga

[PATCH] Decrease number of pointer derefs in exit.c 

Decrease the number of pointer derefs in kernel/exit.c

Benefits of the patch:
 - Fewer pointer dereferences should make the code slightly faster.
 - Size of generated code is smaller
 - improved readability

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 1 changed file with 21 additions and 16 deletions Side-by-side Diff

... ... @@ -1071,6 +1071,9 @@
1071 1071 }
1072 1072  
1073 1073 if (likely(p->real_parent == p->parent) && likely(p->signal)) {
  1074 + struct signal_struct *psig;
  1075 + struct signal_struct *sig;
  1076 +
1074 1077 /*
1075 1078 * The resource counters for the group leader are in its
1076 1079 * own task_struct. Those for dead threads in the group
1077 1080  
1078 1081  
... ... @@ -1087,24 +1090,26 @@
1087 1090 * here reaping other children at the same time.
1088 1091 */
1089 1092 spin_lock_irq(&p->parent->sighand->siglock);
1090   - p->parent->signal->cutime =
1091   - cputime_add(p->parent->signal->cutime,
  1093 + psig = p->parent->signal;
  1094 + sig = p->signal;
  1095 + psig->cutime =
  1096 + cputime_add(psig->cutime,
1092 1097 cputime_add(p->utime,
1093   - cputime_add(p->signal->utime,
1094   - p->signal->cutime)));
1095   - p->parent->signal->cstime =
1096   - cputime_add(p->parent->signal->cstime,
  1098 + cputime_add(sig->utime,
  1099 + sig->cutime)));
  1100 + psig->cstime =
  1101 + cputime_add(psig->cstime,
1097 1102 cputime_add(p->stime,
1098   - cputime_add(p->signal->stime,
1099   - p->signal->cstime)));
1100   - p->parent->signal->cmin_flt +=
1101   - p->min_flt + p->signal->min_flt + p->signal->cmin_flt;
1102   - p->parent->signal->cmaj_flt +=
1103   - p->maj_flt + p->signal->maj_flt + p->signal->cmaj_flt;
1104   - p->parent->signal->cnvcsw +=
1105   - p->nvcsw + p->signal->nvcsw + p->signal->cnvcsw;
1106   - p->parent->signal->cnivcsw +=
1107   - p->nivcsw + p->signal->nivcsw + p->signal->cnivcsw;
  1103 + cputime_add(sig->stime,
  1104 + sig->cstime)));
  1105 + psig->cmin_flt +=
  1106 + p->min_flt + sig->min_flt + sig->cmin_flt;
  1107 + psig->cmaj_flt +=
  1108 + p->maj_flt + sig->maj_flt + sig->cmaj_flt;
  1109 + psig->cnvcsw +=
  1110 + p->nvcsw + sig->nvcsw + sig->cnvcsw;
  1111 + psig->cnivcsw +=
  1112 + p->nivcsw + sig->nivcsw + sig->cnivcsw;
1108 1113 spin_unlock_irq(&p->parent->sighand->siglock);
1109 1114 }
1110 1115