[PATCH/RFC] jump label: make enable/disable o(1)

Previously, I allowed any variable type to be used as the 'key' for the jump label. However, by enforcing a type, we can make use of the contents of the 'key'. This patch thus introduces: +struct jump_label_state { + void *ptr; + int ...

Message posted on the November 30th, 2010 - 3:40 PM ET

[PATCH 0/4][RFC] jump label: introduce default true branch

Hi Peter, I've introduced a new static_branch_def_true() construct, such that the straight line path is the true branch, and we patch a jump to get to the false branch. In order to make jump_label_inc()/dec() work as 'make true'/'make false' with ...

Message posted on the December 21st, 2011 - 2:20 PM ET

[PATCH/RFC 0/2] jump label: simplify API

Hi, The first patch uses the storage space of the jump label key address as a pointer into the update table. In this way, we can find all the addresses that need to be updated without hashing. The second patch introduces: static __always_inline ...

Message posted on the December 16th, 2010 - 1:30 PM ET

[PATCH 0/2] [RFC] jump-label/x86: Compress jmps to 2 bytes where possible

As discussed previously, it can save a lot of text space if we could use the 2 byte jump for jump labels instead of always using the 5 byte version. But to do this, the jmps must be put into the kernel first (always on). Then at compile time, the ...

Message posted on the January 18th, 2012 - 3:00 PM ET

[PATCH RFC V4 00/10] jump-label: allow early jump_label_enable()

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [ Change from V3: Move jump_label_init() much earlier, so that the jump_label mechanism will be reliabily initialized before use. ] While trying to use the jump-label stuff for my PV ...

Message posted on the October 12th, 2011 - 8:10 PM ET

[PATCH RFC V3 0/8] jump-label: allow early jump_label_enable()

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [ Change from V2: add arch_jump_label_transform_static() for use on code which can't possibly be currently executing (ie, a freshly loaded module), which can avoid heavyweight things ...

Message posted on the October 4th, 2011 - 3:20 PM ET

[PATCH RFC V6 0/11] Paravirtualized ticketlocks

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Changes since last posting: (Raghavendra K T) [ - Rebased to linux-3.3-rc6. - used function+enum in place of macro (better type checking) - use cmpxchg while resetting zero status for ...

Message posted on the March 21st, 2012 - 6:20 AM ET

[PATCH RFC V2 0/5] jump-label: allow early jump_label_enable()

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [ This is a new version of this series, which drops the need for any special _early() function in favour of making sure stop_machine() can operate correctly and efficiently in a ...

Message posted on the October 1st, 2011 - 6:00 PM ET

[PATCH][RFC] HPFS: Don't use pointer to out-of-scope array

Hi, There's some suspicious code in fs/hpfs/ea.c::hpfs_read_ea(). First of all, in the 'while (pos < len)' loop a local char array 'ex' is defined and subsequently the pointer variable 'ea' is set to point to the array. Inside the loop we may ...

Message posted on the December 24th, 2010 - 2:50 PM ET

[PATCH RFC 0/8] jump-label: allow early jump_label_enable()

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Hi all, While trying to use the jump-label stuff for my PV ticketlock changes, I had some problems using jump labels early in the kernel's lifetime (pre-SMP). The basic problem is ...

Message posted on the September 29th, 2011 - 7:30 PM ET

[PATCH RFC] reduce runqueue lock contention

This is more of a starting point than a patch, but it is something I've been meaning to look at for a long time. Many different workloads end up hammering very hard on try_to_wake_up, to the point where the runqueue locks dominate CPU profiles. ...

Message posted on the May 20th, 2010 - 4:50 PM ET

[PATCH RFC V4 00/11] Paravirtualized ticketlocks

From: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> [ Changes since last posting: - Stephan Diestelhorst <stephan.diestelhorst@amd.com> pointed out that my old unlock code was unsound, and could lead to deadlocks (at least in ...

Message posted on the October 4th, 2011 - 7:40 PM ET

[PATCH,RFC] perf: panic due to inclied cpu context task_ctx value

hi, following program triggers panic in the current tip tree. run it like: "while [ 1 ]; do ./ctx ; done" reproducer #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include ...

Message posted on the March 24th, 2011 - 11:50 AM ET

[PATCH RFC] x86: initialize initial_page_table before paravirt jumps

As of v2.6.36-rc8-54-gb40827f, initial_page_table needs to be set up to boot. My initial fix for lguest was to cut & paste in the initialization code, but as it's simply byte-twiddling (which could be done at compile time if we were clever ...

Message posted on the December 8th, 2010 - 9:10 PM ET

patch rfc jump