Add IO priority support ('i' key)

14 files changed, 285 insertions, 72 deletions

diff --git a/AffinityPanel.c b/AffinityPanel.c
index 729eec42..8c406fb3 100644
--- a/AffinityPanel.c
+++ b/AffinityPanel.c
@@ -50,7 +50,7 @@ Panel* AffinityPanel_new(ProcessList* pl, Affinity* affinity) {
       } else {
          mode = false;
       }
-      Panel_add(this, (Object*) CheckItem_new(strdup(number), NULL, mode));         
+      Panel_add(this, (Object*) CheckItem_new(strdup(number), NULL, mode));
    }
    return this;
 }
diff --git a/CRT.c b/CRT.c
index 880f4dd1..97f2144e 100644
--- a/CRT.c
+++ b/CRT.c
@@ -129,7 +129,7 @@ static void CRT_handleSIGSEGV(int sgn) {
    fprintf(stderr, "\n\nhtop " VERSION " aborting. Please report bug at http://htop.sf.net\n");
    #ifdef HAVE_EXECINFO_H
    size_t size = backtrace(backtraceArray, sizeof(backtraceArray) / sizeof(void *));
-   fprintf(stderr, "Backtrace: \n");
+   fprintf(stderr, "\n Please include in your report the following backtrace: \n");
    backtrace_symbols_fd(backtraceArray, size, 2);
    fprintf(stderr, "\nAdditionally, in order to make the above backtrace useful,");
    fprintf(stderr, "\nplease also run the following command to generate a disassembly of your binary:");
diff --git a/ChangeLog b/ChangeLog
index 5185f7ad..45b4edbb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,7 @@
 
 What's new in version 1.0.2
 
+* Add IO priority support ('i' key)
 * Avoid deleting .htoprc if it is a symlink
 * BUGFIX: Fix crashes when process list is empty
 
diff --git a/IOPriority.c b/IOPriority.c
new file mode 100644
index 00000000..7b197436
--- /dev/null
+++ b/IOPriority.c
@@ -0,0 +1,41 @@
+/*
+htop - IOPriority.c
+(C) 2004-2012 Hisham H. Muhammad
+Released under the GNU GPL, see the COPYING file
+in the source distribution for its full text.
+
+Based on ionice, 
+Copyright (C) 2005 Jens Axboe <jens@axboe.dk>
+Released under the terms of the GNU General Public License version 2
+*/
+
+#include "IOPriority.h"
+
+/*{
+
+enum {
+   IOPRIO_CLASS_NONE,
+   IOPRIO_CLASS_RT,
+   IOPRIO_CLASS_BE,
+   IOPRIO_CLASS_IDLE,
+};
+
+#define IOPRIO_WHO_PROCESS 1
+
+#define IOPRIO_CLASS_SHIFT (13)
+#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
+
+#define IOPriority_class(ioprio_) ((int) ((ioprio_) >> IOPRIO_CLASS_SHIFT) )
+#define IOPriority_data(ioprio_) ((int) ((ioprio_) & IOPRIO_PRIO_MASK) )
+
+typedef int IOPriority;
+
+#define IOPriority_tuple(class_, data_) (((class_) << IOPRIO_CLASS_SHIFT) | data_)
+
+#define IOPriority_error 0xffffffff
+
+#define IOPriority_None IOPriority_tuple(IOPRIO_CLASS_NONE, 0)
+#define IOPriority_Idle IOPriority_tuple(IOPRIO_CLASS_IDLE, 0)
+
+}*/
+
diff --git a/IOPriority.h b/IOPriority.h
new file mode 100644
index 00000000..d69e30d5
--- /dev/null
+++ b/IOPriority.h
@@ -0,0 +1,43 @@
+/* Do not edit this file. It was automatically generated. */
+
+#ifndef HEADER_IOPriority
+#define HEADER_IOPriority
+/*
+htop - IOPriority.h
+(C) 2004-2012 Hisham H. Muhammad
+Released under the GNU GPL, see the COPYING file
+in the source distribution for its full text.
+
+Based on ionice, 
+Copyright (C) 2005 Jens Axboe <jens@axboe.dk>
+Released under the terms of the GNU General Public License version 2
+*/
+
+
+enum {
+   IOPRIO_CLASS_NONE,
+   IOPRIO_CLASS_RT,
+   IOPRIO_CLASS_BE,
+   IOPRIO_CLASS_IDLE,
+};
+
+#define IOPRIO_WHO_PROCESS 1
+
+#define IOPRIO_CLASS_SHIFT (13)
+#define IOPRIO_PRIO_MASK ((1UL << IOPRIO_CLASS_SHIFT) - 1)
+
+#define IOPriority_class(ioprio_) ((int) ((ioprio_) >> IOPRIO_CLASS_SHIFT) )
+#define IOPriority_data(ioprio_) ((int) ((ioprio_) & IOPRIO_PRIO_MASK) )
+
+typedef int IOPriority;
+
+#define IOPriority_tuple(class_, data_) (((class_) << IOPRIO_CLASS_SHIFT) | data_)
+
+#define IOPriority_error 0xffffffff
+
+#define IOPriority_None IOPriority_tuple(IOPRIO_CLASS_NONE, 0)
+#define IOPriority_Idle IOPriority_tuple(IOPRIO_CLASS_IDLE, 0)
+
+
+
+#endif
diff --git a/IOPriorityPanel.c b/IOPriorityPanel.c
new file mode 100644
index 00000000..bc80b7dc
--- /dev/null
+++ b/IOPriorityPanel.c
@@ -0,0 +1,43 @@
+/*
+htop - IOPriorityPanel.c
+(C) 2004-2012 Hisham H. Muhammad
+Released under the GNU GPL, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "IOPriorityPanel.h"
+
+/*{
+#include "Panel.h"
+#include "IOPriority.h"
+#include "ListItem.h"
+}*/
+
+Panel* IOPriorityPanel_new(IOPriority currPrio) {
+   Panel* this = Panel_new(1, 1, 1, 1, LISTITEM_CLASS, true, ListItem_compare);
+
+   Panel_setHeader(this, "IO Priority:");
+   Panel_add(this, (Object*) ListItem_new("None (based on nice)", IOPriority_None));
+   if (currPrio == IOPriority_None) Panel_setSelected(this, 0);
+   struct { int klass; const char* name; } classes[] = {
+      { .klass = IOPRIO_CLASS_RT, .name = "Realtime" },
+      { .klass = IOPRIO_CLASS_BE, .name = "Best-effort" },
+      { .klass = 0, .name = NULL }
+   };
+   for (int c = 0; classes[c].name; c++) {
+      for (int i = 0; i < 8; i++) {
+         char name[50];
+         snprintf(name, sizeof(name)-1, "%s %d %s", classes[c].name, i, i == 0 ? "(High)" : (i == 7 ? "(Low)" : ""));
+         IOPriority ioprio = IOPriority_tuple(classes[c].klass, i);
+         Panel_add(this, (Object*) ListItem_new(name, ioprio));
+         if (currPrio == ioprio) Panel_setSelected(this, Panel_size(this) - 1);
+      }
+   }
+   Panel_add(this, (Object*) ListItem_new("Idle", IOPriority_Idle));
+   if (currPrio == IOPriority_Idle) Panel_setSelected(this, Panel_size(this) - 1);
+   return this;
+}
+
+IOPriority IOPriorityPanel_getIOPriority(Panel* this) {
+   return (IOPriority) ( ((ListItem*) Panel_getSelected(this))->key );
+}
diff --git a/IOPriorityPanel.h b/IOPriorityPanel.h
new file mode 100644
index 00000000..f87af4e4
--- /dev/null
+++ b/IOPriorityPanel.h
@@ -0,0 +1,20 @@
+/* Do not edit this file. It was automatically generated. */
+
+#ifndef HEADER_IOPriorityPanel
+#define HEADER_IOPriorityPanel
+/*
+htop - IOPriorityPanel.h
+(C) 2004-2012 Hisham H. Muhammad
+Released under the GNU GPL, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "Panel.h"
+#include "IOPriority.h"
+#include "ListItem.h"
+
+Panel* IOPriorityPanel_new(IOPriority currPrio);
+
+IOPriority IOPriorityPanel_getIOPriority(Panel* this);
+
+#endif
diff --git a/Makefile.am b/Makefile.am
index a1ff7d65..05a72e7e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -18,18 +18,18 @@ ClockMeter.c ColorsPanel.c ColumnsPanel.c CPUMeter.c CRT.c \
 DisplayOptionsPanel.c FunctionBar.c Hashtable.c Header.c htop.c ListItem.c \
 LoadAverageMeter.c MemoryMeter.c Meter.c MetersPanel.c Object.c Panel.c \
 BatteryMeter.c Process.c ProcessList.c RichString.c ScreenManager.c Settings.c \
-SignalsPanel.c String.c SwapMeter.c TasksMeter.c TraceScreen.c \
+IOPriorityPanel.c SignalsPanel.c String.c SwapMeter.c TasksMeter.c TraceScreen.c \
 UptimeMeter.c UsersTable.c Vector.c AvailableColumnsPanel.c AffinityPanel.c \
-HostnameMeter.c OpenFilesScreen.c Affinity.c
+HostnameMeter.c OpenFilesScreen.c Affinity.c IOPriority.c
 
 myhtopheaders = AvailableColumnsPanel.h AvailableMetersPanel.h \
 CategoriesPanel.h CheckItem.h ClockMeter.h ColorsPanel.h ColumnsPanel.h \
-CPUMeter.h CRT.h DisplayOptionsPanel.h FunctionBar.h \
+IOPriorityPanel.h CPUMeter.h CRT.h DisplayOptionsPanel.h FunctionBar.h \
 Hashtable.h Header.h htop.h ListItem.h LoadAverageMeter.h MemoryMeter.h \
 BatteryMeter.h Meter.h MetersPanel.h Object.h Panel.h ProcessList.h RichString.h \
 ScreenManager.h Settings.h SignalsPanel.h String.h \
 SwapMeter.h TasksMeter.h TraceScreen.h UptimeMeter.h UsersTable.h Vector.h \
-Process.h AffinityPanel.h HostnameMeter.h OpenFilesScreen.h Affinity.h
+Process.h AffinityPanel.h HostnameMeter.h OpenFilesScreen.h Affinity.h IOPriority.h
 
 SUFFIXES = .h
 
diff --git a/Process.c b/Process.c
index 68edd70e..9cc5c001 100644
--- a/Process.c
+++ b/Process.c
@@ -26,6 +26,7 @@ in the source distribution for its full text.
 #include <sched.h>
 #include <time.h>
 #include <assert.h>
+#include <sys/syscall.h>
 
 #ifdef HAVE_LIBHWLOC
 #include <hwloc/linux.h>
@@ -41,6 +42,7 @@ in the source distribution for its full text.
 /*{
 #include "Object.h"
 #include "Affinity.h"
+#include "IOPriority.h"
 #include <sys/types.h>
 
 #ifndef Process_isKernelThread
@@ -73,6 +75,7 @@ typedef enum ProcessField_ {
    #ifdef HAVE_CGROUP
    CGROUP,
    #endif
+   IO_PRIORITY,
    LAST_PROCESSFIELD
 } ProcessField;
 
@@ -111,6 +114,7 @@ typedef struct Process_ {
    long int priority;
    long int nice;
    long int nlwp;
+   IOPriority ioPriority;
    char starttime_show[8];
    time_t starttime_ctime;
    #ifdef DEBUG
@@ -199,6 +203,7 @@ const char *Process_fieldNames[] = {
 #ifdef HAVE_CGROUP
    "CGROUP",
 #endif
+   "IO_PRIORITY",
 "*** report bug! ***"
 };
 
@@ -224,6 +229,7 @@ const char *Process_fieldTitles[] = {
 #ifdef HAVE_CGROUP
    "    CGROUP ",
 #endif
+   "IO ",
 "*** report bug! ***"
 };
 
@@ -507,7 +513,24 @@ static void Process_writeField(Process* this, RichString* str, ProcessField fiel
    #ifdef HAVE_CGROUP
    case CGROUP: snprintf(buffer, n, "%-10s ", this->cgroup); break;
    #endif
-
+   case IO_PRIORITY: {
+      int klass = IOPriority_class(this->ioPriority);
+      if (klass == IOPRIO_CLASS_NONE) {
+         // see note [1] above
+         snprintf(buffer, n, "B%1d ", (int) (this->nice + 20) / 5);
+      } else if (klass == IOPRIO_CLASS_BE) {
+         snprintf(buffer, n, "B%1d ", IOPriority_data(this->ioPriority));
+      } else if (klass == IOPRIO_CLASS_RT) {
+         attr = CRT_colors[PROCESS_HIGH_PRIORITY];
+         snprintf(buffer, n, "R%1d ", IOPriority_data(this->ioPriority));
+      } else if (this->ioPriority == IOPriority_Idle) {
+         attr = CRT_colors[PROCESS_LOW_PRIORITY]; 
+         snprintf(buffer, n, "id ");
+      } else {
+         snprintf(buffer, n, "?? ");
+      }
+      break;
+   }
    default:
       snprintf(buffer, n, "- ");
    }
@@ -572,6 +595,31 @@ bool Process_setPriority(Process* this, int priority) {
    return (err == 0);
 }
 
+bool Process_changePriorityBy(Process* this, size_t delta) {
+   return Process_setPriority(this, this->nice + delta);
+}
+
+IOPriority Process_updateIOPriority(Process* this) {
+   IOPriority ioprio = syscall(SYS_ioprio_get, IOPRIO_WHO_PROCESS, this->pid);
+   this->ioPriority = ioprio;
+   return ioprio;
+}
+
+bool Process_setIOPriority(Process* this, IOPriority ioprio) {
+   syscall(SYS_ioprio_set, IOPRIO_WHO_PROCESS, this->pid, ioprio);
+   return (Process_updateIOPriority(this) == ioprio);
+}
+
+/*
+[1] Note that before kernel 2.6.26 a process that has not asked for
+an io priority formally uses "none" as scheduling class, but the
+io scheduler will treat such processes as if it were in the best
+effort class. The priority within the best effort class will  be
+dynamically  derived  from  the  cpu  nice level of the process:
+io_priority = (cpu_nice + 20) / 5. -- From ionice(1) man page
+*/
+#define Process_effectiveIOPriority(p_) (IOPriority_class(p_->ioPriority) == IOPRIO_CLASS_NONE ? IOPriority_tuple(IOPRIO_CLASS_BE, (p_->nice + 20) / 5) : p_->ioPriority)
+
 #ifdef HAVE_LIBHWLOC
 
 Affinity* Process_getAffinity(Process* this) {
@@ -631,8 +679,8 @@ bool Process_setAffinity(Process* this, Affinity* affinity) {
 
 #endif
 
-void Process_sendSignal(Process* this, int sgn) {
-   kill(this->pid, sgn);
+void Process_sendSignal(Process* this, size_t sgn) {
+   kill(this->pid, (int) sgn);
 }
 
 int Process_pidCompare(const void* v1, const void* v2) {
@@ -729,7 +777,8 @@ int Process_compare(const void* v1, const void* v2) {
    case CGROUP:
       return strcmp(p1->cgroup ? p1->cgroup : "", p2->cgroup ? p2->cgroup : "");
    #endif
-
+   case IO_PRIORITY:
+      return Process_effectiveIOPriority(p1) - Process_effectiveIOPriority(p2);
    default:
       return (p1->pid - p2->pid);
    }
diff --git a/Process.h b/Process.h
index 2c3e0c33..c5f59346 100644
--- a/Process.h
+++ b/Process.h
@@ -21,6 +21,7 @@ in the source distribution for its full text.
 
 #include "Object.h"
 #include "Affinity.h"
+#include "IOPriority.h"
 #include <sys/types.h>
 
 #ifndef Process_isKernelThread
@@ -53,6 +54,7 @@ typedef enum ProcessField_ {
    #ifdef HAVE_CGROUP
    CGROUP,
    #endif
+   IO_PRIORITY,
    LAST_PROCESSFIELD
 } ProcessField;
 
@@ -91,6 +93,7 @@ typedef struct Process_ {
    long int priority;
    long int nice;
    long int nlwp;
+   IOPriority ioPriority;
    char starttime_show[8];
    time_t starttime_ctime;
    #ifdef DEBUG
@@ -175,6 +178,22 @@ void Process_toggleTag(Process* this);
 
 bool Process_setPriority(Process* this, int priority);
 
+bool Process_changePriorityBy(Process* this, size_t delta);
+
+IOPriority Process_updateIOPriority(Process* this);
+
+bool Process_setIOPriority(Process* this, IOPriority ioprio);
+
+/*
+[1] Note that before kernel 2.6.26 a process that has not asked for
+an io priority formally uses "none" as scheduling class, but the
+io scheduler will treat such processes as if it were in the best
+effort class. The priority within the best effort class will  be
+dynamically  derived  from  the  cpu  nice level of the process:
+extern io_priority;
+*/
+#define Process_effectiveIOPriority(p_) (IOPriority_class(p_->ioPriority) == IOPRIO_CLASS_NONE ? IOPriority_tuple(IOPRIO_CLASS_BE, (p_->nice + 20) / 5) : p_->ioPriority)
+
 #ifdef HAVE_LIBHWLOC
 
 Affinity* Process_getAffinity(Process* this);
@@ -189,7 +208,7 @@ bool Process_setAffinity(Process* this, Affinity* affinity);
 
 #endif
 
-void Process_sendSignal(Process* this, int sgn);
+void Process_sendSignal(Process* this, size_t sgn);
 
 int Process_pidCompare(const void* v1, const void* v2);
 
diff --git a/ProcessList.c b/ProcessList.c
index 14a8b29c..268793f2 100644
--- a/ProcessList.c
+++ b/ProcessList.c
@@ -268,7 +268,7 @@ void ProcessList_printHeader(ProcessList* this, RichString* header) {
    ProcessField* fields = this->fields;
    for (int i = 0; fields[i]; i++) {
       const char* field = Process_fieldTitles[fields[i]];
-      if (this->sortKey == fields[i])
+      if (!this->treeView && this->sortKey == fields[i])
          RichString_append(header, CRT_colors[PANEL_HIGHLIGHT_FOCUS], field);
       else
          RichString_append(header, CRT_colors[PANEL_HEADER_FOCUS], field);
@@ -681,6 +681,7 @@ static bool ProcessList_processEntries(ProcessList* this, const char* dirname, P
       unsigned long long int lasttimes = (process->utime + process->stime);
       if (! ProcessList_readStatFile(process, dirname, name, command))
          goto errorReadingProcess;
+      Process_updateIOPriority(process);
       float percent_cpu = (process->utime + process->stime - lasttimes) / period * 100.0;
       process->percent_cpu = MAX(MIN(percent_cpu, cpus*100.0), 0.0);
       if (isnan(process->percent_cpu)) process->percent_cpu = 0.0;
diff --git a/configure.ac b/configure.ac
index 639d048d..ff6901b1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 # Process this file with autoconf to produce a configure script.
 
 AC_PREREQ(2.65)
-AC_INIT([htop],[1.0.1],[loderunner@users.sourceforge.net])
+AC_INIT([htop],[1.0.2],[loderunner@users.sourceforge.net])
 
 # The following two lines are required by hwloc scripts
 AC_USE_SYSTEM_EXTENSIONS
diff --git a/htop.c b/htop.c
index c8f42e11..44aa8579 100644
--- a/htop.c
+++ b/htop.c
@@ -22,6 +22,7 @@ in the source distribution for its full text.
 #include "TraceScreen.h"
 #include "OpenFilesScreen.h"
 #include "AffinityPanel.h"
+#include "IOPriorityPanel.h"
 
 #include <unistd.h>
 #include <math.h>
@@ -124,18 +125,18 @@ static void showHelp(ProcessList* pl) {
    mvaddstr(12, 0, "   F4 \\: incremental name filtering         K: hide/show kernel threads");
    mvaddstr(13, 0, "  Space: tag processes                      F: cursor follows process");
    mvaddstr(14, 0, "      U: untag all processes              + -: expand/collapse tree");
-   mvaddstr(15, 0, "   F9 k: kill process/tagged processes      P: sort by CPU%");
-   mvaddstr(16, 0, "   ] F7: higher priority (root only)        M: sort by MEM%");
-   mvaddstr(17, 0, "   [ F8: lower priority (+ nice)            T: sort by TIME");
+   mvaddstr(15, 0, "   F9 k: kill process/tagged processes  P M T: sort by CPU%, MEM% or TIME");
+   mvaddstr(16, 0, "   ] F7: higher priority (root only)        i: set IO priority");
+   mvaddstr(17, 0, "   [ F8: lower priority (+ nice)            I: invert sort order");
 #if (HAVE_LIBHWLOC || HAVE_NATIVE_AFFINITY)
    if (pl->cpuCount > 1)
-      mvaddstr(18, 0, "      a: set CPU affinity                   I: invert sort order");
+      mvaddstr(18, 0, "      a: set CPU affinity                F6 >: select sort column");
    else
 #endif
-      mvaddstr(18, 0, "                                            I: invert sort order");
-   mvaddstr(19, 0, "   F2 S: setup                           F6 >: select sort column");
-   mvaddstr(20, 0, "   F1 h: show this help screen              l: list open files with lsof");
-   mvaddstr(21, 0, "  F10 q: quit                               s: trace syscalls with strace");
+      mvaddstr(18, 0, "                                         F6 >: select sort column");
+   mvaddstr(19, 0, "   F2 S: setup                              l: list open files with lsof");
+   mvaddstr(20, 0, "   F1 h: show this help screen              s: trace syscalls with strace");
+   mvaddstr(21, 0, "  F10 q: quit");
 
    attrset(CRT_colors[HELP_BOLD]);
    mvaddstr( 9, 0, " Arrows"); mvaddstr( 9,40, " F5 t");
@@ -144,17 +145,17 @@ static void showHelp(ProcessList* pl) {
    mvaddstr(12, 0, "   F4 \\"); mvaddstr(12,40, "    K");
    mvaddstr(13, 0, "  Space"); mvaddstr(13,40, "    F");
    mvaddstr(14, 0, "      U"); mvaddstr(14,40, "  + -");
-   mvaddstr(15, 0, "   F9 k"); mvaddstr(15,40, "    P");
-   mvaddstr(16, 0, "   ] F7"); mvaddstr(16,40, "    M");
-   mvaddstr(17, 0, "   [ F8"); mvaddstr(17,40, "    T");
-                               mvaddstr(18,40, "    I");
+   mvaddstr(15, 0, "   F9 k"); mvaddstr(15,40, "P M T");
+   mvaddstr(16, 0, "   ] F7"); mvaddstr(16,40, "    i");
+   mvaddstr(17, 0, "   [ F8"); mvaddstr(17,40, "    I");
+                               mvaddstr(18,40, " F6 >");
 #if (HAVE_LIBHWLOC || HAVE_NATIVE_AFFINITY)
    if (pl->cpuCount > 1)
       mvaddstr(18, 0, "      a:");
 #endif
-   mvaddstr(19, 0, "   F2 S"); mvaddstr(19,40, " F6 >");
-   mvaddstr(20, 0, " ? F1 h"); mvaddstr(20,40, "    l");
-   mvaddstr(21, 0, "  F10 q"); mvaddstr(21,40, "    s");
+   mvaddstr(19, 0, "   F2 S"); mvaddstr(19,40, "    l");
+   mvaddstr(20, 0, " ? F1 h"); mvaddstr(20,40, "    s");
+   mvaddstr(21, 0, "  F10 q");
    attrset(CRT_colors[DEFAULT_COLOR]);
 
    attrset(CRT_colors[HELP_BOLD]);
@@ -178,20 +179,30 @@ static void Setup_run(Settings* settings, const Header* header) {
    ScreenManager_delete(scr);
 }
 
-static bool changePriority(Panel* panel, int delta) {
+typedef bool(*ForeachProcessFn)(Process*, size_t);
+
+static bool foreachProcess(Panel* panel, ForeachProcessFn fn, int arg, bool* wasAnyTagged) {
    bool ok = true;
    bool anyTagged = false;
    for (int i = 0; i < Panel_size(panel); i++) {
       Process* p = (Process*) Panel_get(panel, i);
       if (p->tag) {
-         ok = Process_setPriority(p, p->nice + delta) && ok;
+         ok = fn(p, arg) && ok;
          anyTagged = true;
       }
    }
    if (!anyTagged) {
       Process* p = (Process*) Panel_getSelected(panel);
-      if (p) ok = Process_setPriority(p, p->nice + delta) && ok;
+      if (p) ok = fn(p, arg) && ok;
    }
+   if (wasAnyTagged)
+      *wasAnyTagged = anyTagged;
+   return ok;
+}
+
+static bool changePriority(Panel* panel, int delta) {
+   bool anyTagged;
+   bool ok = foreachProcess(panel, (ForeachProcessFn) Process_changePriorityBy, delta, &anyTagged);
    if (!ok)
       beep();
    return anyTagged;
@@ -764,20 +775,6 @@ int main(int argc, char** argv) {
          if (!killPanel) {
             killPanel = (Panel*) SignalsPanel_new(0, 0, 0, 0);
          }
-         bool anyTagged = false;
-         pid_t selectedPid = 0;
-         for (int i = 0; i < Panel_size(panel); i++) {
-            Process* p = (Process*) Panel_get(panel, i);
-            if (p->tag) {
-               anyTagged = true;
-               break;
-            }
-         }
-         if (!anyTagged) {
-            Process* p = (Process*) Panel_getSelected(panel);
-            if (p) selectedPid = p->pid;
-            if (selectedPid == 0) break;
-         }
          SignalsPanel_reset((SignalsPanel*) killPanel);
          const char* fuFunctions[] = {"Send  ", "Cancel ", NULL};
          ListItem* sgn = (ListItem*) pickFromVector(panel, killPanel, 15, headerHeight, fuFunctions, defaultBar, header);
@@ -786,18 +783,7 @@ int main(int argc, char** argv) {
                Panel_setHeader(panel, "Sending...");
                Panel_draw(panel, true);
                refresh();
-               if (anyTagged) {
-                  for (int i = 0; i < Panel_size(panel); i++) {
-                     Process* p = (Process*) Panel_get(panel, i);
-                     if (p->tag) {
-                        Process_sendSignal(p, sgn->key);
-                     }
-                  }
-               } else {
-                  Process* p = (Process*) Panel_getSelected(panel);
-                  if (p->pid == selectedPid)
-                     Process_sendSignal(p, sgn->key);
-               }
+               foreachProcess(panel, (ForeachProcessFn) Process_sendSignal, (size_t) sgn->key, NULL);
                napms(500);
             }
          }
@@ -822,21 +808,8 @@ int main(int argc, char** argv) {
          void* set = pickFromVector(panel, affinityPanel, 15, headerHeight, fuFunctions, defaultBar, header);
          if (set) {
             Affinity* affinity = AffinityPanel_getAffinity(affinityPanel);
-            bool anyTagged = false;
-            bool ok = true;
-            for (int i = 0; i < Panel_size(panel); i++) {
-               Process* p = (Process*) Panel_get(panel, i);
-               if (p->tag) {
-                  ok = Process_setAffinity(p, affinity) && ok;
-                  anyTagged = true;
-               }
-            }
-            if (!anyTagged) {
-               Process* p = (Process*) Panel_getSelected(panel);
-               if (p) ok = Process_setAffinity(p, affinity) && ok;
-            }
-            if (!ok)
-               beep();
+            bool ok = foreachProcess(panel, (ForeachProcessFn) Process_setAffinity, (size_t) affinity, NULL);
+            if (!ok) beep();
             Affinity_delete(affinity);
          }
          Panel_delete((Object*)affinityPanel);
@@ -878,6 +851,25 @@ int main(int argc, char** argv) {
          refreshTimeout = 0;
          break;
       }
+      case 'i':
+      {
+         Process* p = (Process*) Panel_getSelected(panel);
+         if (!p) break;
+         IOPriority ioprio = p->ioPriority;
+         Panel* ioprioPanel = IOPriorityPanel_new(ioprio);
+         const char* fuFunctions[] = {"Set    ", "Cancel ", NULL};
+         void* set = pickFromVector(panel, ioprioPanel, 21, headerHeight, fuFunctions, defaultBar, header);
+         if (set) {
+            IOPriority ioprio = IOPriorityPanel_getIOPriority(ioprioPanel);
+            bool ok = foreachProcess(panel, (ForeachProcessFn) Process_setIOPriority, (size_t) ioprio, NULL);
+            if (!ok)
+               beep();
+         }
+         Panel_delete((Object*)ioprioPanel);
+         ProcessList_printHeader(pl, Panel_getHeader(panel));
+         refreshTimeout = 0;
+         break;
+      }
       case 'I':
       {
          refreshTimeout = 0;
@@ -914,6 +906,8 @@ int main(int argc, char** argv) {
       case KEY_F(5):
          refreshTimeout = 0;
          pl->treeView = !pl->treeView;
+         if (pl->treeView) pl->direction = 1;
+         ProcessList_printHeader(pl, Panel_getHeader(panel));
          ProcessList_expandTree(pl);
          settings->changed = true;
          if (following != -1) continue;
diff --git a/htop.h b/htop.h
index 227f36d3..8d8ed7ed 100644
--- a/htop.h
+++ b/htop.h
@@ -15,6 +15,8 @@ in the source distribution for its full text.
 
 #define COPYRIGHT "(C) 2004-2011 Hisham Muhammad"
 
+typedef bool(*ForeachProcessFn)(Process*, size_t);
+
 typedef struct IncBuffer_;
 
 int main(int argc, char** argv);