mirror of
https://github.com/varun-r-mallya/sysprof.git
synced 2025-12-31 20:36:25 +00:00
Performance improvements
This commit is contained in:
Søren Sandmann Pedersen
179
sysprof-module.c
179
sysprof-module.c
@ -37,89 +37,92 @@ static void on_timer(unsigned long);
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/*
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* Wrappers to cover up kernel differences in timer handling
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*/
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#ifdef KERNEL24
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static struct tq_struct timer_task =
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{
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{ NULL, NULL },
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0,
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on_timer,
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NULL
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};
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int exiting = 0;
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#else
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static struct timer_list timer;
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#endif
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static void
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init_timeout (void)
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{
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#ifdef KERNEL24
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/* no setup needed */
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#else
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init_timer(&timer);
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timer.function = on_timer;
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#endif
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}
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static void
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remove_timeout(void)
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{
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#ifdef KERNEL24
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exiting = 1;
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sleep_on (&wait_for_exit);
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#else
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del_timer (&timer);
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#endif
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}
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static void
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add_timeout(unsigned int interval,
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TimeoutFunc f)
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{
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#ifdef KERNEL24
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queue_task(&timer_task, &tq_timer);
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#else
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mod_timer(&timer, jiffies + INTERVAL);
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#endif
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}
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/*
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* The portable part of the driver starts here
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*/
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typedef struct userspace_reader userspace_reader;
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struct userspace_reader
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{
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struct task_struct *task;
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unsigned long user_page;
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unsigned long kernel_page;
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struct page *page;
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};
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static void
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init_userspace_reader (userspace_reader *reader,
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struct task_struct *task)
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{
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reader->task = task;
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reader->user_page = 0;
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reader->kernel_page = 0;
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reader->page = NULL;
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}
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static int
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read_task_address (struct task_struct *task, unsigned long address, int *result)
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read_user_space (userspace_reader *reader,
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unsigned long address,
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unsigned long *result)
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{
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unsigned long page_addr = (address & PAGE_MASK);
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int found;
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struct page *page;
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void *kaddr;
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unsigned long user_page = (address & PAGE_MASK);
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int res;
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if (!task || !task->mm)
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return 0;
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found = get_user_pages (task, task->mm, page_addr, 1, 0, 0, &page, NULL);
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if (!found)
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if (user_page == 0)
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return 0;
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kaddr = kmap_atomic (page, KM_SOFTIRQ0);
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if (!reader->user_page || user_page != reader->user_page) {
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int found;
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struct page *page;
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if (reader->user_page)
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kunmap (reader->page);
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if (get_user (res, (int *)kaddr + (address - page_addr) / 4)) {
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kunmap_atomic (page, KM_SOFTIRQ0);
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return 0;
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reader->user_page = user_page;
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found = get_user_pages (reader->task, reader->task->mm, user_page,
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1, 0, 0, &page, NULL);
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if (!found)
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return 0;
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reader->kernel_page = (unsigned long)kmap (page);
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reader->page = page;
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}
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kunmap_atomic (page, KM_SOFTIRQ0);
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if (__get_user (res, (int *)(reader->kernel_page + (address - user_page))) != 0)
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return 0;
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*result = res;
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return 1;
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}
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static void
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done_userspace_reader (userspace_reader *reader)
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{
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if (reader->user_page)
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kunmap (reader->page);
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}
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typedef struct StackFrame StackFrame;
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struct StackFrame {
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unsigned long next;
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@ -127,7 +130,7 @@ struct StackFrame {
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};
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static int
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read_frame (struct task_struct *task, unsigned long addr, StackFrame *frame)
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read_frame (userspace_reader *reader, unsigned long addr, StackFrame *frame)
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{
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if (!addr || !frame)
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return 0;
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@ -135,10 +138,10 @@ read_frame (struct task_struct *task, unsigned long addr, StackFrame *frame)
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frame->next = 0;
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frame->return_address = 0;
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if (!read_task_address (task, addr, (int *)&(frame->next)))
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if (!read_user_space (reader, addr, &(frame->next)))
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return 0;
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if (!read_task_address (task, addr + 4, (int *)&(frame->return_address)))
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if (!read_user_space (reader, addr + 4, &(frame->return_address)))
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return 0;
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return 1;
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@ -156,6 +159,7 @@ generate_stack_trace(struct task_struct *task,
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struct pt_regs *regs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) task->thread_info)) - 1;
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StackFrame frame;
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unsigned long addr;
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userspace_reader reader;
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int i;
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memset(trace, 0, sizeof (SysprofStackTrace));
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@ -169,55 +173,13 @@ generate_stack_trace(struct task_struct *task,
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addr = regs->ebp;
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#if 0
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printk (KERN_ALERT "in generate\n");
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#endif
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#if 0
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read_frame (task, addr, &frame);
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#endif
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while (i < SYSPROF_MAX_ADDRESSES && read_frame (task, addr, &frame)) {
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init_userspace_reader (&reader, task);
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while (i < SYSPROF_MAX_ADDRESSES && read_frame (&reader, addr, &frame) &&
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addr < START_OF_STACK && addr >= regs->esp) {
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trace->addresses[i++] = (void *)frame.return_address;
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addr = frame.next;
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}
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#if 0
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printk (KERN_ALERT "done (frame.next = %p)\n", frame.next);
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#endif
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#if 0
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read_frame (task, regs->ebp, &frame);
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while (i < SYSPROF_MAX_ADDRESSES &&
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(long)frame < (long)START_OF_STACK &&
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(long)frame >= regs->esp) {
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void *next = NULL;
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printk(KERN_ALERT "esp: %lx\n", regs->esp);
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printk(KERN_ALERT "ebp: %lx\n", regs->ebp);
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if (verify_area(VERIFY_READ, frame, sizeof(StackFrame)) == 0) {
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void *return_address;
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read_task_address (task, (unsigned long)return_address, (int *)&(frame->return_address));
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read_task_address (task, (unsigned long)next, (int *)&(frame->next));
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trace->addresses[i++] = return_address;
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if ((long)next <= (long)frame)
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next = NULL;
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else
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printk(KERN_ALERT "bad next\n");
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}
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else
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printk(KERN_ALERT "couldn't verify\n");
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frame = next;
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if (frame == NULL)
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printk(KERN_ALERT "frame %d is null\n", i);
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}
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#endif
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done_userspace_reader (&reader);
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trace->n_addresses = i;
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if (i == SYSPROF_MAX_ADDRESSES)
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@ -269,29 +231,10 @@ on_timer(unsigned long dong)
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{
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static int n_ticks = 0;
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#ifdef KERNEL24
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if (exiting) {
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wake_up (&wait_for_exit);
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return;
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}
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#endif
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++n_ticks;
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if (
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#ifdef KERNEL24
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current && current->pid != 0 &&
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(n_ticks % (HZ / SAMPLES_PER_SECOND)) == 0
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#else
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current && current->pid != 0
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#endif
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)
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if (current && current->pid != 0)
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{
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#ifdef KERNEL24
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struct pt_regs *regs = (struct pt_regs *)(
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(long)current + THREAD_SIZE - sizeof (struct pt_regs));
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#endif
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queue_stack (current);
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}
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@ -306,10 +249,6 @@ procfile_read(char *buffer,
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int *eof,
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void *data)
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{
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#if 0
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if (buffer_len < sizeof (SysprofStackTrace))
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return -ENOMEM;
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#endif
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wait_event_interruptible (wait_for_trace, head != tail);
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*buffer_location = (char *)tail;
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if (tail++ == &stack_traces[N_TRACES - 1])
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