Question

我有类似于mon的应用程序,在初始阶段进行一些软盘处理。为了避免减缓其他任务,我在视窗上做的是:

SetPriorityClass(GetCurrentProcess(), PROCESS_MODE_BACKGROUND_BEGIN);

// initialization tasks

SetPriorityClass(GetCurrentProcess(), PROCESS_MODE_BACKGROUND_END);

// daemon is ready and running at normal priority

AFAIK, on Unices I can calls nice or set priority and reduction the process priority but I can t rise to what it was at process creation (i.e. there s no amount to the second SetPriorityClass in Occupation)less 我请我享有超级用户特权。难道我没有机会再做一次呢? (我知道,我可以建立一个低优先的初始化线,等待主线完成,但我更愿意避免)

edit: Bonus Point for Equal SetThreadPriority (GetCurrentThread(), PHREED_MODE_BACKGROUND_BEG信息网);SetThreadPriority (GetCurrentread(), PHED_MODE_BACKGROUND_END);

Answer 1

阁下说,你的处理是磁盘密集的,因此使用<条码> nic/代码>的解决办法赢得了笔工作。 <代码>nice处理万国邮联优先准入问题,而不是I/O准入问题。 PROCESS_MODE_BACKGROUND_BEGIN 降低I/O的优先地位和CPU的优先地位,并要求在XP和老板中不存在斜体特征。

控制I/O优先权并非跨越Unices,而是在现代的六氯环己烷中找到解决办法。页: 1

关键职能电话是ioprio_set, 您必须通过sys calls打电话。总结:

static int ioprio_set(int which, int who, int ioprio)
{
    return syscall(SYS_ioprio_set, which, who, ioprio);
}

For full example sources, 。

根据许可,您进入背景模式的有:IOPRIO_PRIO_VALUE(IO_PRIO_CLASS_IDLE,0)IOPRIO_PRIO_VALUE(IO_PRIO_CLASS_BE,7)。然后顺序应为:

#define IOPRIO_PRIO_VALUE(class, data)  (((class) << IOPRIO_CLASS_SHIFT) | data)

ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IO_PRIO_CLASS_BE,7));
// Do work
ioprio_set(IOPRIO_WHO_PROCESS, 0, IOPRIO_PRIO_VALUE(IO_PRIO_CLASS_BE,4));

请注意,你们许多人没有获准回到你原先的奥尼优先事项,因此,你需要再次获得最佳努力。

Answer 2

实际上,如果你拥有一个合理的最近 kernel,则可能有一个解决办法。在这里,图西人阵说:

In Linux kernels before 2.6.12, an unprivileged process may use setpriority() only to (irreversibly) lower its own or another process’s nice value.

Since kernel 2.6.12, Linux provides the RLIMIT_NICE resource limit, which permits unprivileged processes to increase nice values. An unprivileged process can raise its own nice value to the maximum specified by the formula 20 – rlim_cur, where rlim_cur is the current RLIMIT_NICE soft resource limit.

基本上,你们必须:

Use ulimit -e to set RLIMIT_NICE
Use setpriority as usual

这方面的一个例子

<<>Edit>code>/etc/security/limits.conf/strong>。增编

cnicutar    -    nice    -10

www.un.org/Depts/DGACM/index_spanish.htm 使用ulimit

cnicutar@aiur:~$ ulimit -e
30

我们喜欢这一限制,因此我们不会改变它。

http://www.ohchr.org。

cnicutar@aiur:~$ nice -n -10 ls tmp
cnicutar@aiur:~$ 

cnicutar@aiur:~$ nice -n -11 ls tmp
nice: cannot set niceness: Permission denied

<><>>>>>>>>>>>> 优先程度<>/代码>。

#include <stdio.h>
#include <sys/resource.h>
#include <unistd.h>

int main()
{
        int rc;

        printf("We are being nice!
");
        /* set our nice to 10 */
        rc = setpriority(PRIO_PROCESS, 0, 10);
        if (0 != rc) {
                perror("setpriority");
        }

        sleep(1);

        printf("Stop being nice
");
        /* set our nice to -10 */
        rc = setpriority(PRIO_PROCESS, 0, -10);
        if (0 != rc) {
                perror("setpriority");
        }

        return 0;
}

www.un.org/Depts/DGACM/index_spanish.htm 试验方案

cnicutar@aiur:~$ ./nnice 
We are being nice!
Stop being nice
cnicutar@aiur:~$

唯一的缺点是,它不能与其他不统一(或者说是Unices<>/em>?

Answer 3

大力降低优先程度,然后回馈:

fork()
CHILD: lower its priority
PARENT: wait for the child (keeping original parent s priority)
CHILD: do the job (in lower priority)
PARENT: continue with original priority after child is finished.

这应当是可使用的解决办法。

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