- 07 May, 2012 1 commit
-
-
Greg Kroah-Hartman authored
This reverts commit 04db6e5f. Odds are, we really don't want to revert all of these, and need to be more careful in the future to make sure we don't break the build of other arches. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 05 May, 2012 3 commits
-
-
Jim Cromie authored
I left 1 printk which uses __FILE__, __LINE__ explicitly, which should not be subject to generic preferences expressed via pr_fmt(). + tweaks suggested by Joe Perches: - add doing to irq-enabled warning, like others. It wont happen often.. - change sysfs failure crit, not just err, make it 1 line in logs. - coalese 2 format fragments into 1 >80 char line cc: Joe Perches <joe@perches.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
These arent currently needed, so drop them. Some will probably get re-added when static-branches are added, but include loops prevent that at present. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
In commit 9fb48c74: "params: add 3rd arg to option handler callback signature", the if-guard added to the pr_debug was overzealous; no callers pass NULL, and existing code above and below the guard assumes as much. Change the if-guard to match, and silence the Smack complaint. CC: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 04 May, 2012 7 commits
-
-
Mark Brown authored
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Mark Brown authored
APIs using devres frequently want to implement a "remove and free the resource" operation so it seems sensible that they should be able to just have devres do the freeing for them since that's a big part of what devres is all about. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Mark Brown authored
It's not massively obvious (at least to me) that removing and freeing a resource does not involve calling the release function for the resource but rather only removes the management of it. Make the documentation more explicit. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Michael Davidson authored
DEVICE_INT_ATTR() should use device_show_int() and device_store_int() not device_show_ulong() and device_store_ulong() Signed-off-by: Michael Davidson <md@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
H Hartley Sweeten authored
NULL not 0 should be used with pointers. Just remove the offending lines since they will default to NULL anyway. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Mark Brown authored
Some accessory detection mechanisms are able to detect that something is physically present in the socket separately to identifying what is present in the socket. This information can be useful to applications, for example allowing them to indicate that a potentially broken accessory is present, so provide a standard way to report it to userspace. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Santosh Shilimkar authored
Make TI_EMIF depends on ARCH_OMAP2PLUS to avoid build breaks on other architectures. In future if other TI non OMAP socs start using it, the dependency can be extended. Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 02 May, 2012 10 commits
-
-
H Hartley Sweeten authored
Fix the section mismatch be renaming the struct platform_driver variable. Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: MyungJoo Ham <myungjoo.ham@samsung.com> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Sasikantha babu authored
Since no one using "dup_name", removed it completely in sysfs_rename. Signed-off-by: Sasikantha babu <sasikanth.v19@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Greg Kroah-Hartman authored
This was done to resolve a merge issue with the init/main.c file. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
Add debug entries for: 1. calculated registers per frequency 2. last polled value of MR4(temperature level of LPDDR2 memory) Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
Add settings that are not dependent on frequency or any other transient parameters. This includes - power managment control init - impedence calibration control - frequency independent phy configuration registers - initialization of temperature polling Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
Add an ISR for EMIF that: 1. reports details of access errors 2. takes action on thermal events Also clear all interrupts on shut-down. Pending IRQs may casue problems during warm-reset. Temperature handling: EMIF can be configured to poll the temperature level of an LPDDR2 device from the MR4 mode register in the device. EMIF generates an interrupt whenever it identifies a temperature level change between two consecutive pollings. Some of the timing parameters need to be de-rated at high temperatures. The interrupt handler takes care of doing this and also takes care of going back to nominal settings when temperature falls back to nominal levels. Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
Change SDRAM timings and other settings as necessary on voltage and frequency changes. We calculate these register settings based on data from the device data sheet and inputs such a frequency, voltage state(stable or ramping), temperature level etc. TODO: frequency and voltage change handling needs to be integrated with clock framework and regulator framework respectively. This is not done today due to missing pieces in the kernel. Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
EMIF is an SDRAM controller used in various Texas Instruments SoCs. EMIF supports, based on its revision, one or more of LPDDR2/DDR2/DDR3 protocols. Add the basic infrastructure for EMIF driver that includes driver registration, probe, parsing of platform data etc. Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
Add register offsets and bit field definitions for EMIF module in TI SoCs Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Aneesh V authored
add LPDDR2 data from the JEDEC spec JESD209-2. The data includes: 1. Addressing information for LPDDR2 memories of different densities and types(S2/S4) 2. AC timing data. This data will useful for memory controller device drivers. Right now this is used by the TI EMIF SDRAM controller driver. Signed-off-by: Aneesh V <aneesh@ti.com> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Benoit Cousson <b-cousson@ti.com> [santosh.shilimkar@ti.com: Moved to drivers/memory from drivers/misc] Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Tested-by: Lokesh Vutla <lokeshvutla@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 01 May, 2012 1 commit
-
-
Jim Cromie authored
drivers/infiniband/ulp/srp/ib_srp.c #defines pr_fmt() PFX fmt, but PFX is not #defined until after <linux/*> headers are included. This results in a bad expansion of the pr_warn() in the stub function. 2084c2084 < printk("<4>" PFX "dyndbg supported only in " "CONFIG_DYNAMIC_DEBUG builds\n") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 30 Apr, 2012 13 commits
-
-
Jim Cromie authored
1- Call dynamic_debug_init() from early_initcall, not arch_initcall. 2- Call dynamic_debug_init_debugfs() from fs_initcall, not module_init. RFC: This works for me on a 64 bit desktop and a i586 SBC, but is untested on other arches. I presume there is or was a reason original code used arch_initcall, maybe the constraints have changed. This makes facility available as soon as possible. 2nd change has a downside when dynamic_debug.verbose=1; all the vpr_info()s called in the proc-fs code are activated, causing voluminous output from dmesg. TBD: Im unsure of this explanation, but the output is there. This could be fixed by changing those callsites to v2pr_info(if verbose > 1). 1st change is still not early enough to enable pr_debugs in kernel/params, so parsing of boot-args isnt logged. The reparse of those args is however visible after params.dyndbg="+p" is processed. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
In dynamic-debug-howto.txt: - add section: Debug Messages at Module Initialization Time - update flags indicators in example outputs to include '=' - make flags descriptions tabular - add item on '_' flag-char - add dyndbg, boot-args examples - rewrap some paragraphs with long lines In Kconfig.debug, note that compiling with -DDEBUG enables all pr_debug()s in that code. In kernel-parameters.txt, add dyndbg and module.dyndbg items, and deprecate ddebug_query. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
Pass module name into ddebug_exec_queries(), ddebug_exec_query(), and ddebug_parse_query() as separate parameter. In ddebug_parse_query(), the module name is added into the query struct before the query-string is parsed. This allows the query-string to be shorter: instead of: $modname.dyndbg="module $modname +fp" do this: $modname.dyndbg="+fp" Omitting "module $modname" from the query string is actually required for $modname.dyndbg rules; the set-only-once check added in a previous patch will throw an error if its added again. ddebug_query="..." has no $modname associated with it, so the query string may include it. This also fixes redundant "module $modname" otherwise needed to handle multiple queries per string: $modname.dyndbg="func foo +fp; func bar +fp" Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
Print ram usage of dynamic-debug tables and verbose section so user knows cost of enabling CONFIG_DYNAMIC_DEBUG. This only counts the size of the _ddebug tables for builtins and the __verbose section that they refer to, not those used in loadable modules. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
We dont want errors while parsing ddebug_query to unload ddebug tables, so set success after tables are loaded, and return 0 after query parsing is done. Simplify error handling code since its no longer used for success, and change goto label to out_err to clarify this. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
Refactor ddebug_dyndbg_boot_param_cb and ddebug_dyndbg_module_param_cb into a common helper function, and call it from both. The handling of foo.dyndbg is unneeded by the latter, but harmless. The 2 callers differ only by pr_info and the return code they pass to the helper for when an unknown param is handled. I could slightly reduce dmesg clutter by putting the vpr_info in the common helper, after the return on_err, but that loses __func__ context, is overly silent on module_cb unknown param errors, and the clutter is only when dynamic_debug.verbose=1 anyway. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
With ddebug_dyndbg_boot_params_cb() handling bare dyndbg params, we dont need ddebug_query param anymore. Add a warning when processing ddebug_query= param that it is deprecated, and to change it to dyndbg= Add a deprecation notice for v3.8 to feature-removal-schedule.txt, and add a suggested deprecation period of 3 releases to the header. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
This introduces a fake module param $module.dyndbg. Its based upon Thomas Renninger's $module.ddebug boot-time debugging patch from https://lkml.org/lkml/2010/9/15/397 The 'fake' module parameter is provided for all modules, whether or not they need it. It is not explicitly added to each module, but is implemented in callbacks invoked from parse_args. For builtin modules, dynamic_debug_init() now directly calls parse_args(..., &ddebug_dyndbg_boot_params_cb), to process the params undeclared in the modules, just after the ddebug tables are processed. While its slightly weird to reprocess the boot params, parse_args() is already called repeatedly by do_initcall_levels(). More importantly, the dyndbg queries (given in ddebug_query or dyndbg params) cannot be activated until after the ddebug tables are ready, and reusing parse_args is cleaner than doing an ad-hoc parse. This reparse would break options like inc_verbosity, but they probably should be params, like verbosity=3. ddebug_dyndbg_boot_params_cb() handles both bare dyndbg (aka: ddebug_query) and module-prefixed dyndbg params, and ignores all other parameters. For example, the following will enable pr_debug()s in 4 builtin modules, in the order given: dyndbg="module params +p; module aio +p" module.dyndbg=+p pci.dyndbg For loadable modules, parse_args() in load_module() calls ddebug_dyndbg_module_params_cb(). This handles bare dyndbg params as passed from modprobe, and errors on other unknown params. Note that modprobe reads /proc/cmdline, so "modprobe foo" grabs all foo.params, strips the "foo.", and passes these to the kernel. ddebug_dyndbg_module_params_cb() is again called for the unknown params; it handles dyndbg, and errors on others. The "doing" arg added previously contains the module name. For non CONFIG_DYNAMIC_DEBUG builds, the stub function accepts and ignores $module.dyndbg params, other unknowns get -ENOENT. If no param value is given (as in pci.dyndbg example above), "+p" is assumed, which enables all pr_debug callsites in the module. The dyndbg fake parameter is not shown in /sys/module/*/parameters, thus it does not use any resources. Changes to it are made via the control file. Also change pr_info in ddebug_exec_queries to vpr_info, no need to see it all the time. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> CC: Thomas Renninger <trenn@suse.de> CC: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
Add a 3rd arg, named "doing", to unknown-options callbacks invoked from parse_args(). The arg is passed as: "Booting kernel" from start_kernel(), initcall_level_names[i] from do_initcall_level(), mod->name from load_module(), via parse_args(), parse_one() parse_args() already has the "name" parameter, which is renamed to "doing" to better reflect current uses 1,2 above. parse_args() passes it to an altered parse_one(), which now passes it down into the unknown option handler callbacks. The mod->name will be needed to handle dyndbg for loadable modules, since params passed by modprobe are not qualified (they do not have a "$modname." prefix), and by the time the unknown-param callback is called, the module name is not otherwise available. Minor tweaks: Add param-name to parse_one's pr_debug(), current message doesnt identify the param being handled, add it. Add a pr_info to print current level and level_name of the initcall, and number of registered initcalls at that level. This adds 7 lines to dmesg output, like: initlevel:6=device, 172 registered initcalls Drop "parameters" from initcall_level_names[], its unhelpful in the pr_info() added above. This array is passed into parse_args() by do_initcall_level(). CC: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
clean up some space-before-tabs problems. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Jim Cromie authored
Use vpr_info to declutter code, reduce indenting, and change one additional pr_info call in ddebug_exec_queries. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Acked-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Greg Kroah-Hartman authored
This reverts commit f19420c1. It contained lots of errors and warnings and shouldn't have ever been applied, that was my fault, sorry. Cc: Markus Franke <markus.franke@s2002.tu-chemnitz.de> Cc: Evgeniy Polyakov <zbr@ioremap.net>, Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Chanwoo Choi authored
This patch inform the state of only one cable instead of previous data including the state of 32 cables to notifee which use extcon_register_interest() function to monitor whether the specific cable is attachd or detached. Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
- 29 Apr, 2012 5 commits
-
-
Linus Torvalds authored
-
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
Pull power management fixes from Rafael J. Wysocki: "Fix for an issue causing hibernation to hang on systems with highmem (that practically means i386) due to broken memory management (bug introduced in 3.2, so -stable material) and PM documentation update making the freezer documentation follow the code again after some recent updates." * tag 'pm-for-3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM / Freezer / Docs: Update documentation about freezing of tasks PM / Hibernate: fix the number of pages used for hibernate/thaw buffering
-
Linus Torvalds authored
The autofs packet size has had a very unfortunate size problem on x86: because the alignment of 'u64' differs in 32-bit and 64-bit modes, and because the packet data was not 8-byte aligned, the size of the autofsv5 packet structure differed between 32-bit and 64-bit modes despite looking otherwise identical (300 vs 304 bytes respectively). We first fixed that up by making the 64-bit compat mode know about this problem in commit a32744d4 ("autofs: work around unhappy compat problem on x86-64"), and that made a 32-bit 'systemd' work happily on a 64-bit kernel because everything then worked the same way as on a 32-bit kernel. But it turned out that 'automount' had actually known and worked around this problem in user space, so fixing the kernel to do the proper 32-bit compatibility handling actually *broke* 32-bit automount on a 64-bit kernel, because it knew that the packet sizes were wrong and expected those incorrect sizes. As a result, we ended up reverting that compatibility mode fix, and thus breaking systemd again, in commit fcbf94b9. With both automount and systemd doing a single read() system call, and verifying that they get *exactly* the size they expect but using different sizes, it seemed that fixing one of them inevitably seemed to break the other. At one point, a patch I seriously considered applying from Michael Tokarev did a "strcmp()" to see if it was automount that was doing the operation. Ugly, ugly. However, a prettier solution exists now thanks to the packetized pipe mode. By marking the communication pipe as being packetized (by simply setting the O_DIRECT flag), we can always just write the bigger packet size, and if user-space does a smaller read, it will just get that partial end result and the extra alignment padding will simply be thrown away. This makes both automount and systemd happy, since they now get the size they asked for, and the kernel side of autofs simply no longer needs to care - it could pad out the packet arbitrarily. Of course, if there is some *other* user of autofs (please, please, please tell me it ain't so - and we haven't heard of any) that tries to read the packets with multiple writes, that other user will now be broken - the whole point of the packetized mode is that one system call gets exactly one packet, and you cannot read a packet in pieces. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Marcos Paulo de Souza authored
The file Documentation/power/freezing-of-tasks.txt was still referencing the TIF_FREEZE flag, that was removed by the commit d88e4cb6(freezer: remove now unused TIF_FREEZE). This patch removes all the references of TIF_FREEZE that were left behind. Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
-
Linus Torvalds authored
The actual internal pipe implementation is already really about individual packets (called "pipe buffers"), and this simply exposes that as a special packetized mode. When we are in the packetized mode (marked by O_DIRECT as suggested by Alan Cox), a write() on a pipe will not merge the new data with previous writes, so each write will get a pipe buffer of its own. The pipe buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn will tell the reader side to break the read at that boundary (and throw away any partial packet contents that do not fit in the read buffer). End result: as long as you do writes less than PIPE_BUF in size (so that the pipe doesn't have to split them up), you can now treat the pipe as a packet interface, where each read() system call will read one packet at a time. You can just use a sufficiently big read buffer (PIPE_BUF is sufficient, since bigger than that doesn't guarantee atomicity anyway), and the return value of the read() will naturally give you the size of the packet. NOTE! We do not support zero-sized packets, and zero-sized reads and writes to a pipe continue to be no-ops. Also note that big packets will currently be split at write time, but that the size at which that happens is not really specified (except that it's bigger than PIPE_BUF). Currently that limit is the system page size, but we might want to explicitly support bigger packets some day. The main user for this is going to be the autofs packet interface, allowing us to stop having to care so deeply about exact packet sizes (which have had bugs with 32/64-bit compatibility modes). But user space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will fail with an EINVAL on kernels that do not support this interface. Tested-by: Michael Tokarev <mjt@tls.msk.ru> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Ian Kent <raven@themaw.net> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: stable@kernel.org # needed for systemd/autofs interaction fix Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-