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author | Ingo Molnar <mingo@elte.hu> | 2008-11-18 16:48:49 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-11-18 16:48:49 +0100 |
commit | 73f56c0d35e6427081a4eabd620d8b8d8a35bd09 (patch) | |
tree | 9fe1a2577baea03f3a6ec4a5e79f3ff26c4ee0ae /Documentation/printk-formats.txt | |
parent | 0af40a4b1050c050e62eb1dc30b82d5ab22bf221 (diff) | |
parent | 8501c45cc32c311ae755a2d5ac8c4a5f04908d42 (diff) |
Merge branch 'iommu-fixes-2.6.28' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/linux-2.6-iommu into x86/urgent
Diffstat (limited to 'Documentation/printk-formats.txt')
-rw-r--r-- | Documentation/printk-formats.txt | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt new file mode 100644 index 000000000000..1b5a5ddbc3ef --- /dev/null +++ b/Documentation/printk-formats.txt @@ -0,0 +1,35 @@ +If variable is of Type, use printk format specifier: +--------------------------------------------------------- + int %d or %x + unsigned int %u or %x + long %ld or %lx + unsigned long %lu or %lx + long long %lld or %llx + unsigned long long %llu or %llx + size_t %zu or %zx + ssize_t %zd or %zx + +Raw pointer value SHOULD be printed with %p. + +u64 SHOULD be printed with %llu/%llx, (unsigned long long): + + printk("%llu", (unsigned long long)u64_var); + +s64 SHOULD be printed with %lld/%llx, (long long): + + printk("%lld", (long long)s64_var); + +If <type> is dependent on a config option for its size (e.g., sector_t, +blkcnt_t, phys_addr_t, resource_size_t) or is architecture-dependent +for its size (e.g., tcflag_t), use a format specifier of its largest +possible type and explicitly cast to it. Example: + + printk("test: sector number/total blocks: %llu/%llu\n", + (unsigned long long)sector, (unsigned long long)blockcount); + +Reminder: sizeof() result is of type size_t. + +Thank you for your cooperation and attention. + + +By Randy Dunlap <rdunlap@xenotime.net> |