diff options
| -rw-r--r-- | Documentation/IRQ-affinity.txt | 17 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 11 | ||||
| -rw-r--r-- | include/linux/bitmap.h | 5 | ||||
| -rw-r--r-- | include/linux/cpumask.h | 15 | ||||
| -rw-r--r-- | kernel/irq/proc.c | 54 | ||||
| -rw-r--r-- | lib/bitmap.c | 109 |
6 files changed, 188 insertions, 23 deletions
diff --git a/Documentation/IRQ-affinity.txt b/Documentation/IRQ-affinity.txt index b4a615b7840..7890fae1852 100644 --- a/Documentation/IRQ-affinity.txt +++ b/Documentation/IRQ-affinity.txt @@ -4,10 +4,11 @@ ChangeLog: SMP IRQ affinity -/proc/irq/IRQ#/smp_affinity specifies which target CPUs are permitted -for a given IRQ source. It's a bitmask of allowed CPUs. It's not allowed -to turn off all CPUs, and if an IRQ controller does not support IRQ -affinity then the value will not change from the default 0xffffffff. +/proc/irq/IRQ#/smp_affinity and /proc/irq/IRQ#/smp_affinity_list specify +which target CPUs are permitted for a given IRQ source. It's a bitmask +(smp_affinity) or cpu list (smp_affinity_list) of allowed CPUs. It's not +allowed to turn off all CPUs, and if an IRQ controller does not support +IRQ affinity then the value will not change from the default of all cpus. /proc/irq/default_smp_affinity specifies default affinity mask that applies to all non-active IRQs. Once IRQ is allocated/activated its affinity bitmask @@ -54,3 +55,11 @@ round-trip min/avg/max = 0.1/0.5/585.4 ms This time around IRQ44 was delivered only to the last four processors. i.e counters for the CPU0-3 did not change. +Here is an example of limiting that same irq (44) to cpus 1024 to 1031: + +[root@moon 44]# echo 1024-1031 > smp_affinity +[root@moon 44]# cat smp_affinity +1024-1031 + +Note that to do this with a bitmask would require 32 bitmasks of zero +to follow the pertinent one. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 60740e8ecb3..f4817802406 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -574,6 +574,12 @@ The contents of each smp_affinity file is the same by default: > cat /proc/irq/0/smp_affinity ffffffff +There is an alternate interface, smp_affinity_list which allows specifying +a cpu range instead of a bitmask: + + > cat /proc/irq/0/smp_affinity_list + 1024-1031 + The default_smp_affinity mask applies to all non-active IRQs, which are the IRQs which have not yet been allocated/activated, and hence which lack a /proc/irq/[0-9]* directory. @@ -583,12 +589,13 @@ reports itself as being attached. This hardware locality information does not include information about any possible driver locality preference. prof_cpu_mask specifies which CPUs are to be profiled by the system wide -profiler. Default value is ffffffff (all cpus). +profiler. Default value is ffffffff (all cpus if there are only 32 of them). The way IRQs are routed is handled by the IO-APIC, and it's Round Robin between all the CPUs which are allowed to handle it. As usual the kernel has more info than you and does a better job than you, so the defaults are the -best choice for almost everyone. +best choice for almost everyone. [Note this applies only to those IO-APIC's +that support "Round Robin" interrupt distribution.] There are three more important subdirectories in /proc: net, scsi, and sys. The general rule is that the contents, or even the existence of these diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h index daf8c480c78..dcafe0bf000 100644 --- a/include/linux/bitmap.h +++ b/include/linux/bitmap.h @@ -55,7 +55,8 @@ * bitmap_parse(buf, buflen, dst, nbits) Parse bitmap dst from kernel buf * bitmap_parse_user(ubuf, ulen, dst, nbits) Parse bitmap dst from user buf * bitmap_scnlistprintf(buf, len, src, nbits) Print bitmap src as list to buf - * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from list + * bitmap_parselist(buf, dst, nbits) Parse bitmap dst from kernel buf + * bitmap_parselist_user(buf, dst, nbits) Parse bitmap dst from user buf * bitmap_find_free_region(bitmap, bits, order) Find and allocate bit region * bitmap_release_region(bitmap, pos, order) Free specified bit region * bitmap_allocate_region(bitmap, pos, order) Allocate specified bit region @@ -129,6 +130,8 @@ extern int bitmap_scnlistprintf(char *buf, unsigned int len, const unsigned long *src, int nbits); extern int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits); +extern int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, + unsigned long *dst, int nbits); extern void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, int bits); extern int bitmap_bitremap(int oldbit, diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h index bae6fe24d1f..b24ac56477b 100644 --- a/include/linux/cpumask.h +++ b/include/linux/cpumask.h @@ -547,6 +547,21 @@ static inline int cpumask_parse_user(const char __user *buf, int len, } /** + * cpumask_parselist_user - extract a cpumask from a user string + * @buf: the buffer to extract from + * @len: the length of the buffer + * @dstp: the cpumask to set. + * + * Returns -errno, or 0 for success. + */ +static inline int cpumask_parselist_user(const char __user *buf, int len, + struct cpumask *dstp) +{ + return bitmap_parselist_user(buf, len, cpumask_bits(dstp), + nr_cpumask_bits); +} + +/** * cpulist_scnprintf - print a cpumask into a string as comma-separated list * @buf: the buffer to sprintf into * @len: the length of the buffer diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index 834899f2500..64e3df6ab1e 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -19,7 +19,7 @@ static struct proc_dir_entry *root_irq_dir; #ifdef CONFIG_SMP -static int irq_affinity_proc_show(struct seq_file *m, void *v) +static int show_irq_affinity(int type, struct seq_file *m, void *v) { struct irq_desc *desc = irq_to_desc((long)m->private); const struct cpumask *mask = desc->irq_data.affinity; @@ -28,7 +28,10 @@ static int irq_affinity_proc_show(struct seq_file *m, void *v) if (irqd_is_setaffinity_pending(&desc->irq_data)) mask = desc->pending_mask; #endif - seq_cpumask(m, mask); + if (type) + seq_cpumask_list(m, mask); + else + seq_cpumask(m, mask); seq_putc(m, '\n'); return 0; } @@ -59,7 +62,18 @@ static int irq_affinity_hint_proc_show(struct seq_file *m, void *v) #endif int no_irq_affinity; -static ssize_t irq_affinity_proc_write(struct file *file, +static int irq_affinity_proc_show(struct seq_file *m, void *v) +{ + return show_irq_affinity(0, m, v); +} + +static int irq_affinity_list_proc_show(struct seq_file *m, void *v) +{ + return show_irq_affinity(1, m, v); +} + + +static ssize_t write_irq_affinity(int type, struct file *file, const char __user *buffer, size_t count, loff_t *pos) { unsigned int irq = (int)(long)PDE(file->f_path.dentry->d_inode)->data; @@ -72,7 +86,10 @@ static ssize_t irq_affinity_proc_write(struct file *file, if (!alloc_cpumask_var(&new_value, GFP_KERNEL)) return -ENOMEM; - err = cpumask_parse_user(buffer, count, new_value); + if (type) + err = cpumask_parselist_user(buffer, count, new_value); + else + err = cpumask_parse_user(buffer, count, new_value); if (err) goto free_cpumask; @@ -100,11 +117,28 @@ free_cpumask: return err; } +static ssize_t irq_affinity_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + return write_irq_affinity(0, file, buffer, count, pos); +} + +static ssize_t irq_affinity_list_proc_write(struct file *file, + const char __user *buffer, size_t count, loff_t *pos) +{ + return write_irq_affinity(1, file, buffer, count, pos); +} + static int irq_affinity_proc_open(struct inode *inode, struct file *file) { return single_open(file, irq_affinity_proc_show, PDE(inode)->data); } +static int irq_affinity_list_proc_open(struct inode *inode, struct file *file) +{ + return single_open(file, irq_affinity_list_proc_show, PDE(inode)->data); +} + static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file) { return single_open(file, irq_affinity_hint_proc_show, PDE(inode)->data); @@ -125,6 +159,14 @@ static const struct file_operations irq_affinity_hint_proc_fops = { .release = single_release, }; +static const struct file_operations irq_affinity_list_proc_fops = { + .open = irq_affinity_list_proc_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, + .write = irq_affinity_list_proc_write, +}; + static int default_affinity_show(struct seq_file *m, void *v) { seq_cpumask(m, irq_default_affinity); @@ -289,6 +331,10 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc) proc_create_data("affinity_hint", 0400, desc->dir, &irq_affinity_hint_proc_fops, (void *)(long)irq); + /* create /proc/irq/<irq>/smp_affinity_list */ + proc_create_data("smp_affinity_list", 0600, desc->dir, + &irq_affinity_list_proc_fops, (void *)(long)irq); + proc_create_data("node", 0444, desc->dir, &irq_node_proc_fops, (void *)(long)irq); #endif diff --git a/lib/bitmap.c b/lib/bitmap.c index 91e0ccfdb42..41baf02924e 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -571,8 +571,11 @@ int bitmap_scnlistprintf(char *buf, unsigned int buflen, EXPORT_SYMBOL(bitmap_scnlistprintf); /** - * bitmap_parselist - convert list format ASCII string to bitmap + * __bitmap_parselist - convert list format ASCII string to bitmap * @bp: read nul-terminated user string from this buffer + * @buflen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @is_user: location of buffer, 0 indicates kernel space * @maskp: write resulting mask here * @nmaskbits: number of bits in mask to be written * @@ -587,20 +590,63 @@ EXPORT_SYMBOL(bitmap_scnlistprintf); * %-EINVAL: invalid character in string * %-ERANGE: bit number specified too large for mask */ -int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) +static int __bitmap_parselist(const char *buf, unsigned int buflen, + int is_user, unsigned long *maskp, + int nmaskbits) { unsigned a, b; + int c, old_c, totaldigits; + const char __user *ubuf = buf; + int exp_digit, in_range; + totaldigits = c = 0; bitmap_zero(maskp, nmaskbits); do { - if (!isdigit(*bp)) - return -EINVAL; - b = a = simple_strtoul(bp, (char **)&bp, BASEDEC); - if (*bp == '-') { - bp++; - if (!isdigit(*bp)) + exp_digit = 1; + in_range = 0; + a = b = 0; + + /* Get the next cpu# or a range of cpu#'s */ + while (buflen) { + old_c = c; + if (is_user) { + if (__get_user(c, ubuf++)) + return -EFAULT; + } else + c = *buf++; + buflen--; + if (isspace(c)) + continue; + + /* + * If the last character was a space and the current + * character isn't '\0', we've got embedded whitespace. + * This is a no-no, so throw an error. + */ + if (totaldigits && c && isspace(old_c)) + return -EINVAL; + + /* A '\0' or a ',' signal the end of a cpu# or range */ + if (c == '\0' || c == ',') + break; + + if (c == '-') { + if (exp_digit || in_range) + return -EINVAL; + b = 0; + in_range = 1; + exp_digit = 1; + continue; + } + + if (!isdigit(c)) return -EINVAL; - b = simple_strtoul(bp, (char **)&bp, BASEDEC); + + b = b * 10 + (c - '0'); + if (!in_range) + a = b; + exp_digit = 0; + totaldigits++; } if (!(a <= b)) return -EINVAL; @@ -610,13 +656,52 @@ int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) set_bit(a, maskp); a++; } - if (*bp == ',') - bp++; - } while (*bp != '\0' && *bp != '\n'); + } while (buflen && c == ','); return 0; } + +int bitmap_parselist(const char *bp, unsigned long *maskp, int nmaskbits) +{ + char *nl = strchr(bp, '\n'); + int len; + + if (nl) + len = nl - bp; + else + len = strlen(bp); + + return __bitmap_parselist(bp, len, 0, maskp, nmaskbits); +} EXPORT_SYMBOL(bitmap_parselist); + +/** + * bitmap_parselist_user() + * + * @ubuf: pointer to user buffer containing string. + * @ulen: buffer size in bytes. If string is smaller than this + * then it must be terminated with a \0. + * @maskp: pointer to bitmap array that will contain result. + * @nmaskbits: size of bitmap, in bits. + * + * Wrapper for bitmap_parselist(), providing it with user buffer. + * + * We cannot have this as an inline function in bitmap.h because it needs + * linux/uaccess.h to get the access_ok() declaration and this causes + * cyclic dependencies. + */ +int bitmap_parselist_user(const char __user *ubuf, + unsigned int ulen, unsigned long *maskp, + int nmaskbits) +{ + if (!access_ok(VERIFY_READ, ubuf, ulen)) + return -EFAULT; + return __bitmap_parselist((const char *)ubuf, + ulen, 1, maskp, nmaskbits); +} +EXPORT_SYMBOL(bitmap_parselist_user); + + /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap |