![Tejun Heo](/assets/img/avatar_default.png)
percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
218 lines
6.3 KiB
C
218 lines
6.3 KiB
C
/*
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* Copyright 2008 by Andreas Eversberg <andreas@eversberg.eu>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* Quick API description:
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*
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* A clock source registers using mISDN_register_clock:
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* name = text string to name clock source
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* priority = value to priorize clock sources (0 = default)
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* ctl = callback function to enable/disable clock source
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* priv = private pointer of clock source
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* return = pointer to clock source structure;
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*
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* Note: Callback 'ctl' can be called before mISDN_register_clock returns!
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* Also it can be called during mISDN_unregister_clock.
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*
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* A clock source calls mISDN_clock_update with given samples elapsed, if
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* enabled. If function call is delayed, tv must be set with the timestamp
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* of the actual event.
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*
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* A clock source unregisters using mISDN_unregister_clock.
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*
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* To get current clock, call mISDN_clock_get. The signed short value
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* counts the number of samples since. Time since last clock event is added.
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*
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*/
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/stddef.h>
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#include <linux/spinlock.h>
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#include <linux/mISDNif.h>
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#include "core.h"
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static u_int *debug;
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static LIST_HEAD(iclock_list);
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static DEFINE_RWLOCK(iclock_lock);
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static u16 iclock_count; /* counter of last clock */
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static struct timeval iclock_tv; /* time stamp of last clock */
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static int iclock_tv_valid; /* already received one timestamp */
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static struct mISDNclock *iclock_current;
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void
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mISDN_init_clock(u_int *dp)
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{
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debug = dp;
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do_gettimeofday(&iclock_tv);
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}
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static void
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select_iclock(void)
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{
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struct mISDNclock *iclock, *bestclock = NULL, *lastclock = NULL;
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int pri = -128;
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list_for_each_entry(iclock, &iclock_list, list) {
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if (iclock->pri > pri) {
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pri = iclock->pri;
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bestclock = iclock;
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}
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if (iclock_current == iclock)
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lastclock = iclock;
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}
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if (lastclock && bestclock != lastclock) {
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/* last used clock source still exists but changes, disable */
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if (*debug & DEBUG_CLOCK)
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printk(KERN_DEBUG "Old clock source '%s' disable.\n",
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lastclock->name);
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lastclock->ctl(lastclock->priv, 0);
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}
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if (bestclock && bestclock != iclock_current) {
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/* new clock source selected, enable */
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if (*debug & DEBUG_CLOCK)
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printk(KERN_DEBUG "New clock source '%s' enable.\n",
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bestclock->name);
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bestclock->ctl(bestclock->priv, 1);
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}
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if (bestclock != iclock_current) {
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/* no clock received yet */
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iclock_tv_valid = 0;
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}
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iclock_current = bestclock;
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}
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struct mISDNclock
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*mISDN_register_clock(char *name, int pri, clockctl_func_t *ctl, void *priv)
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{
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u_long flags;
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struct mISDNclock *iclock;
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if (*debug & (DEBUG_CORE | DEBUG_CLOCK))
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printk(KERN_DEBUG "%s: %s %d\n", __func__, name, pri);
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iclock = kzalloc(sizeof(struct mISDNclock), GFP_ATOMIC);
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if (!iclock) {
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printk(KERN_ERR "%s: No memory for clock entry.\n", __func__);
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return NULL;
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}
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strncpy(iclock->name, name, sizeof(iclock->name)-1);
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iclock->pri = pri;
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iclock->priv = priv;
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iclock->ctl = ctl;
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write_lock_irqsave(&iclock_lock, flags);
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list_add_tail(&iclock->list, &iclock_list);
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select_iclock();
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write_unlock_irqrestore(&iclock_lock, flags);
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return iclock;
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}
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EXPORT_SYMBOL(mISDN_register_clock);
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void
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mISDN_unregister_clock(struct mISDNclock *iclock)
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{
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u_long flags;
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if (*debug & (DEBUG_CORE | DEBUG_CLOCK))
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printk(KERN_DEBUG "%s: %s %d\n", __func__, iclock->name,
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iclock->pri);
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write_lock_irqsave(&iclock_lock, flags);
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if (iclock_current == iclock) {
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if (*debug & DEBUG_CLOCK)
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printk(KERN_DEBUG
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"Current clock source '%s' unregisters.\n",
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iclock->name);
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iclock->ctl(iclock->priv, 0);
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}
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list_del(&iclock->list);
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select_iclock();
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write_unlock_irqrestore(&iclock_lock, flags);
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}
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EXPORT_SYMBOL(mISDN_unregister_clock);
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void
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mISDN_clock_update(struct mISDNclock *iclock, int samples, struct timeval *tv)
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{
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u_long flags;
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struct timeval tv_now;
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time_t elapsed_sec;
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int elapsed_8000th;
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write_lock_irqsave(&iclock_lock, flags);
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if (iclock_current != iclock) {
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printk(KERN_ERR "%s: '%s' sends us clock updates, but we do "
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"listen to '%s'. This is a bug!\n", __func__,
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iclock->name,
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iclock_current ? iclock_current->name : "nothing");
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iclock->ctl(iclock->priv, 0);
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write_unlock_irqrestore(&iclock_lock, flags);
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return;
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}
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if (iclock_tv_valid) {
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/* increment sample counter by given samples */
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iclock_count += samples;
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if (tv) { /* tv must be set, if function call is delayed */
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iclock_tv.tv_sec = tv->tv_sec;
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iclock_tv.tv_usec = tv->tv_usec;
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} else
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do_gettimeofday(&iclock_tv);
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} else {
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/* calc elapsed time by system clock */
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if (tv) { /* tv must be set, if function call is delayed */
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tv_now.tv_sec = tv->tv_sec;
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tv_now.tv_usec = tv->tv_usec;
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} else
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do_gettimeofday(&tv_now);
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elapsed_sec = tv_now.tv_sec - iclock_tv.tv_sec;
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elapsed_8000th = (tv_now.tv_usec / 125)
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- (iclock_tv.tv_usec / 125);
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if (elapsed_8000th < 0) {
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elapsed_sec -= 1;
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elapsed_8000th += 8000;
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}
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/* add elapsed time to counter and set new timestamp */
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iclock_count += elapsed_sec * 8000 + elapsed_8000th;
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iclock_tv.tv_sec = tv_now.tv_sec;
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iclock_tv.tv_usec = tv_now.tv_usec;
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iclock_tv_valid = 1;
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if (*debug & DEBUG_CLOCK)
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printk("Received first clock from source '%s'.\n",
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iclock_current ? iclock_current->name : "nothing");
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}
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write_unlock_irqrestore(&iclock_lock, flags);
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}
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EXPORT_SYMBOL(mISDN_clock_update);
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unsigned short
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mISDN_clock_get(void)
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{
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u_long flags;
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struct timeval tv_now;
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time_t elapsed_sec;
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int elapsed_8000th;
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u16 count;
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read_lock_irqsave(&iclock_lock, flags);
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/* calc elapsed time by system clock */
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do_gettimeofday(&tv_now);
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elapsed_sec = tv_now.tv_sec - iclock_tv.tv_sec;
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elapsed_8000th = (tv_now.tv_usec / 125) - (iclock_tv.tv_usec / 125);
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if (elapsed_8000th < 0) {
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elapsed_sec -= 1;
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elapsed_8000th += 8000;
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}
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/* add elapsed time to counter */
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count = iclock_count + elapsed_sec * 8000 + elapsed_8000th;
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read_unlock_irqrestore(&iclock_lock, flags);
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return count;
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}
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EXPORT_SYMBOL(mISDN_clock_get);
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