diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/printk-formats.txt | 29 | ||||
| -rw-r--r-- | Documentation/vm/balance | 14 | ||||
| -rw-r--r-- | Documentation/vm/split_page_table_lock | 4 |
3 files changed, 39 insertions, 8 deletions
diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt index 2216eb187c21..b784c270105f 100644 --- a/Documentation/printk-formats.txt +++ b/Documentation/printk-formats.txt @@ -23,6 +23,10 @@ Example: Reminder: sizeof() result is of type size_t. +The kernel's printf does not support %n. For obvious reasons, floating +point formats (%e, %f, %g, %a) are also not recognized. Use of any +unsupported specifier or length qualifier results in a WARN and early +return from vsnprintf. Raw pointer value SHOULD be printed with %p. The kernel supports the following extended format specifiers for pointer types: @@ -119,6 +123,7 @@ Raw buffer as an escaped string: If field width is omitted the 1 byte only will be escaped. Raw buffer as a hex string: + %*ph 00 01 02 ... 3f %*phC 00:01:02: ... :3f %*phD 00-01-02- ... -3f @@ -234,6 +239,7 @@ UUID/GUID addresses: Passed by reference. dentry names: + %pd{,2,3,4} %pD{,2,3,4} @@ -256,6 +262,8 @@ struct va_format: va_list *va; }; + Implements a "recursive vsnprintf". + Do not use this feature without some mechanism to verify the correctness of the format string and va_list arguments. @@ -284,6 +292,27 @@ bitmap and its derivatives such as cpumask and nodemask: Passed by reference. +Network device features: + + %pNF 0x000000000000c000 + + For printing netdev_features_t. + + Passed by reference. + +Command from struct task_struct + + %pT ls + + For printing executable name excluding path from struct + task_struct. + + Passed by reference. + +If you add other %p extensions, please extend lib/test_printf.c with +one or more test cases, if at all feasible. + + Thank you for your cooperation and attention. diff --git a/Documentation/vm/balance b/Documentation/vm/balance index c46e68cf9344..964595481af6 100644 --- a/Documentation/vm/balance +++ b/Documentation/vm/balance @@ -1,12 +1,14 @@ Started Jan 2000 by Kanoj Sarcar <kanoj@sgi.com> -Memory balancing is needed for non __GFP_WAIT as well as for non -__GFP_IO allocations. +Memory balancing is needed for !__GFP_ATOMIC and !__GFP_KSWAPD_RECLAIM as +well as for non __GFP_IO allocations. -There are two reasons to be requesting non __GFP_WAIT allocations: -the caller can not sleep (typically intr context), or does not want -to incur cost overheads of page stealing and possible swap io for -whatever reasons. +The first reason why a caller may avoid reclaim is that the caller can not +sleep due to holding a spinlock or is in interrupt context. The second may +be that the caller is willing to fail the allocation without incurring the +overhead of page reclaim. This may happen for opportunistic high-order +allocation requests that have order-0 fallback options. In such cases, +the caller may also wish to avoid waking kswapd. __GFP_IO allocation requests are made to prevent file system deadlocks. diff --git a/Documentation/vm/split_page_table_lock b/Documentation/vm/split_page_table_lock index 6dea4fd5c961..62842a857dab 100644 --- a/Documentation/vm/split_page_table_lock +++ b/Documentation/vm/split_page_table_lock @@ -54,8 +54,8 @@ everything required is done by pgtable_page_ctor() and pgtable_page_dtor(), which must be called on PTE table allocation / freeing. Make sure the architecture doesn't use slab allocator for page table -allocation: slab uses page->slab_cache and page->first_page for its pages. -These fields share storage with page->ptl. +allocation: slab uses page->slab_cache for its pages. +This field shares storage with page->ptl. PMD split lock only makes sense if you have more than two page table levels. |