aboutsummaryrefslogtreecommitdiff
AgeCommit message (Collapse)Author
2006-05-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband: IB/ipath: tidy up white space in a few files IB/ipath: fix label name in interrupt handler IB/ipath: improve sparse annotation IB/ipath: simplify IB timer usage IB/ipath: simplify RC send posting IB/ipath: prevent hardware from being accessed during reset IB/ipath: fix verbs registration IB/ipath: change handling of PIO buffers IB/ipath: iterate over correct number of ports during reset IB/ipath: set up 32-bit DMA mask if 64-bit setup fails IB/ipath: fix race with exposing reset file IB/mthca: Fix offset in query_gid method
2006-05-01[PATCH] timer TSC check suspend notifier changeShaohua Li
At suspend time, the TSC CPUFREQ_SUSPENDCHANGE notifier change might wrongly enable interrupt. cpufreq driver suspend/resume is in interrupt disabled environment. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Cc: Pavel Machek <pavel@ucw.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] x86_64: make PC Speaker driver workMikael Pettersson
The PC Speaker driver's ->probe() routine doesn't even get called in the 64-bit kernels. The reason for that is that the arch code apparently has to explictly add a "pcspkr" platform device in order for the driver core to call the ->probe() routine. arch/i386/kernel/setup.c unconditionally adds a "pcspkr" device, but the x86_64 kernel has no code at all related to the PC Speaker. The patch below copies the relevant code from i386 to x86_64, which makes the PC Speaker work for me on x86_64. Cc: Dmitry Torokhov <dtor_core@ameritech.net> Acked-by: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] genrtc: fix read on 64-bit platformsAtsushi Nemoto
Fix genrtc's read() routine for 64-bit platforms. Current gen_rtc_read() stores 64bit integer and returns 8 even if an user tried to read a 32bit integer. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] RTC: rtc-dev tweak for 64-bit kernelAtsushi Nemoto
Make rtc-dev work well on 64-bit platforms with 32-bit userland. On those platforms, users might try to read 32-bit integer value. This patch make rtc-dev's read() work well for both "int" and "long" size. This tweak is came from genrtc driver. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] s390: bug in setup_rt_frameHeiko Carstens
Consider return value of __put_user() when setting up a signal frame instead of ignoring it. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] s390: fix ipd handlingHeiko Carstens
As pointed out by Paulo Marques <pmarques@grupopie.com> MAX_IPD_TIME is by a factor of ten too small. Since this means that we allow ten times more IPDs in the intended time frame this could result in a cpu check stop of a physical cpu. Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] powerpc: cell: Add numa id to struct spuJeremy Kerr
Add an nid member to the spu structure, and store the numa id of the spu there on creation. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] powerpc: Allow devices to register with numa topologyJeremy Kerr
Change of_node_to_nid() to traverse the device tree, looking for a numa id. Cell uses this to assign ids to SPUs, which are children of the CPU node. Existing users of of_node_to_nid() are altered to use of_node_to_nid_single(), which doesn't do the traversal. Export an attach_sysdev_to_node() function, allowing system devices (eg. SPUs) to link themselves into the numa topology in sysfs. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] spufs: fix for CONFIG_NUMAJoel H Schopp
Based on an older patch from Mike Kravetz <kravetz@us.ibm.com> We need to have a mem_map for high addresses in order to make fops->no_page work on spufs mem and register files. So far, we have used the memory_present() function during early bootup, but that did not work when CONFIG_NUMA was enabled. We now use the __add_pages() function to add the mem_map when loading the spufs module, which is a lot nicer. Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] sparsemem interaction with memory add bug fixesMike Kravetz
This patch fixes two bugs with the way sparsemem interacts with memory add. They are: - memory leak if memmap for section already exists - calling alloc_bootmem_node() after boot These bugs were discovered and a first cut at the fixes were provided by Arnd Bergmann <arnd@arndb.de> and Joel Schopp <jschopp@us.ibm.com>. Signed-off-by: Mike Kravetz <kravetz@us.ibm.com> Signed-off-by: Joel Schopp <jschopp@austin.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] Altix: correct ioc3 port orderPat Gefre
Currently loading the ioc3 as a module will cause the ports to be numbered in reverse order. This mod maintains the proper order of cards for port numbering. Signed-off-by: Patrick Gefre <pfg@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] page migration: Fix fallback behavior for dirty pagesChristoph Lameter
Currently we check PageDirty() in order to make the decision to swap out the page. However, the dirty information may be only be contained in the ptes pointing to the page. We need to first unmap the ptes before checking for PageDirty(). If unmap is successful then the page count of the page will also be decreased so that pageout() works properly. This is a fix necessary for 2.6.17. Without this fix we may migrate dirty pages for filesystems without migration functions. Filesystems may keep pointers to dirty pages. Migration of dirty pages can result in the filesystem keeping pointers to freed pages. Unmapping is currently not be separated out from removing all the references to a page and moving the mapping. Therefore try_to_unmap will be called again in migrate_page() if the writeout is successful. However, it wont do anything since the ptes are already removed. The coming updates to the page migration code will restructure the code so that this is no longer necessary. Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: uml-makefile-nicer uses SYMLINK incorrectlyJeff Dike
Blaisorblade's uml-makefile-nicer makes a V=0 build say SYMLINK where what's happening is really a LINK. Signed-off-by: Jeff Dike <jdike@addtoit.com> Acked-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: export symbols added by GCC hardenedPaolo 'Blaisorblade' Giarrusso
GCC hardened introduces additional symbol refererences (for the canary and friends), also in modules - add weak export_symbols for them. We already tested that the weak declaration creates no problem on both GCC's providing the function definition and on GCC's which don't provide it. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: cleanup unprofile expression and build infrastructurePaolo 'Blaisorblade' Giarrusso
*) Rather than duplicate in various buggy ways the application of CFLAGS_NO_HARDENING and UNPROFILE (which apply to the same files), centralize it in Makefile.rules. UNPROFILE_OBJS mustn't be listed in USER_OBJS but are compiled as such. I've also verified that unprofile didn't work in the current form, because we set _c_flags directly (using CFLAGS and not USER_CFLAGS, which is wrong), which is normally used by c_flags, but we also override c_flags for all USER_OBJS, and there we don't call unprofile. Instead it only worked for unmap.o, the only one which wasn't a USER_OBJ. We need to set c_flags (which is not a public Kbuild API) to clear a lot of compilation flags like -nostdinc which Kbuild forces on everything. *) Rather than $(CFLAGS_$(notdir $@)), which expands to CFLAGS_anObj.s when building "anObj.s", use $(CFLAGS_$(*F).o) which always accesses CFLAGS_anObj.o, like done by Kbuild. *) Make c_flags apply to all targets having the same basename, rather than listing .s, .i, .lst and .o, with the use (which I tested) of $(USER_OBJS:.o=.%): c_flags = ... and of - $(obj)/unmap.c: _c_flags = ... + $(obj)/unmap.%: _c_flags = ... Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: fix compilation and execution with hardened GCCPaolo 'Blaisorblade' Giarrusso
To make some half-assembly stubs compile, disable various "hardened" GCC features: *) we can't make it build PIC code as we need %ebx to do syscalls and GCC wants it free for PIC *) we can't leave stack protection as the stub is moved (not relocated!) in memory so the RIP-relative access to the canary tries reading from an unmapped address and causes a segfault, since we move the stub of various megabytes (the exact amount will be decided at runtime) away from the link-time address. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: use Kbuild tracking for all files and fix compilation outputPaolo 'Blaisorblade' Giarrusso
Move the build of user-offsets to arch/um/sys-$(SUBARCH), where it's located. So we can also build it via Kbuild with its dependency tracking rather than by hand. While hacking here, fix also a lot of little cosmetic things. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: search from uml_net in a more reasonable PATHMattia Dongili
Append /usr/lib/uml to the existing PATH environment variable to let execvp() search uml_net in FHS compliant locations. Signed-off-by: Mattia Dongili <malattia@linux.it> Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: fix patch mismergePaolo 'Blaisorblade' Giarrusso
I sent a patch, it was applied as cda402b283c34a24b091f78eee116963e9494762, then it was applied again as 181ae4005d0a4010802be534d929b38c42b9ac06 by mistake. But while the 1st time it modified (correctly) cow_header_v3, the 2nd it modified cow_header_v3_broken. Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: error handling fixesJeff Dike
Blairsorblade noticed some confusion between our use of a system call's return value and errno. This patch fixes a number of related bugs - using errno instead of a return value using a return value instead of errno forgetting to negate a error return to get a positive error code Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: update defconfigJeff Dike
Bring defconfig up to date. Also disable CONFIG_BLK_DEV_UBD_SYNC by default. By performing synchronous I/O to the host, it slows things down, only protects against host crashes, and can make a UML appear to hang while it waits for the host's disk. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: clean up after MADVISE_REMOVEJeff Dike
The MADVISE_REMOVE-checking code didn't clean up after itself. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: remove NULL checks and add some CodingStyleJesper Juhl
Remove redundant NULL checks before [kv]free + small CodingStyle cleanup for arch/ Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: skas0 support for 2G/2G hostsJoris van Rantwijk
A quick hack to allow skas0 mode to run on 2G/2G hosts. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] uml: fix iomem list traversalVictor V. Vengerov
We need to walk the region list properly. Signed-off-by: Jeff Dike <jdike@addtoit.com> Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] silence initcall warningsAndrew Morton
Suppress the initcall-return-value warnings unless initcall_debug was specified. They do find bugs, but they're extremely small ones and as Andi points out, people get distressed. Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] i386: Remove apic= warningAndi Kleen
The apic= option can be used to set the APIC driver too. When that is done this code would always produce bogus warnings. Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] i386: Fix overflow in e820_all_mappedAndi Kleen
The 32bit version of e820_all_mapped() needs to use u64 to avoid overflows on PAE systems. Pointed out by Jan Beulich Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] i386/x86-64: Fix ACPI disabled LAPIC handling mismergeAndi Kleen
The patch I submitted earlier to fix disabled LAPIC handling in ACPI was mismerged for some reason I still don't quite understand. Parts of it was applied to the wrong function. This patch fixes it up. Cc: <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] x86_64: Add compat_sys_vmsplice and use it in x86-64Andi Kleen
Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] md: Fix 'rdev->nr_pending' count when retrying barrier requestsNeilBrown
When retrying a failed BIO_RW_BARRIER request, we need to keep the reference in ->nr_pending over the whole retry. Currently, we only hold the reference if the failed request is the *last* one to finish - which is silly, because it would normally be the first to finish. So move the rdev_dec_pending call up into the didn't-fail branch. As the rdev isn't used in the later code, calling rdev_dec_pending earlier doesn't hurt. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] md: Improve detection of lack of barrier support in raid1NeilBrown
Move the test for 'do barrier work' down a bit so that if the first write to a raid1 is a BIO_RW_BARRIER write, the checking done by superblock writes will cause the right thing to happen. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] md: Change ENOTSUPP to EOPNOTSUPPNeilBrown
Because that is what you get if a BIO_RW_BARRIER isn't supported! Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] md: Fixed refcounting/locking when attempting read error correction ↵NeilBrown
in raid10 We need to hold a reference to rdevs while reading and writing to attempt to correct read errors. This reference must be taken under an rcu lock. Signed-off-by: Neil Brown <neilb@suse.de> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] md: Avoid oops when attempting to fix read errors on raid10NeilBrown
We should add to the counter for the rdev *after* checking if the rdev is NULL!!! Signed-off-by: Neil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01[PATCH] s390: make qeth buildableBastian Blank
Signed-off-by: Bastian Blank <bastian@waldi.eu.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: "David S. Miller" <davem@davemloft.net> Acked-by: Jeff Garzik <jeff@garzik.org> Acked-by: Frank Pavlic <fpavlic@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01IB/ipath: tidy up white space in a few filesBryan O'Sullivan
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: fix label name in interrupt handlerBryan O'Sullivan
Names that are the opposite of their intended meanings are not so helpful. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: improve sparse annotationBryan O'Sullivan
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: simplify IB timer usageBryan O'Sullivan
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: simplify RC send postingBryan O'Sullivan
Remove some unnecessarily complicated tests. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: prevent hardware from being accessed during resetBryan O'Sullivan
The reset code now turns off the PRESENT flag during a reset, so that other code won't attempt to access a device that's in mid-reset. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: fix verbs registrationBryan O'Sullivan
Remember when the verbs layer unregisters from the lower-level code. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: change handling of PIO buffersBryan O'Sullivan
Different ipath hardware types have different numbers of buffers available, so we decide on the counts ourselves unless we are specifically overridden with a module parameter. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: iterate over correct number of ports during resetBryan O'Sullivan
Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: set up 32-bit DMA mask if 64-bit setup failsBryan O'Sullivan
Some systems do not set up 64-bit maps on systems with 2GB or less of memory installed, so we have to fall back to trying a 32-bit setup. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01IB/ipath: fix race with exposing reset fileBryan O'Sullivan
We were accidentally exposing the "reset" sysfs file more than once per device. Signed-off-by: Bryan O'Sullivan <bos@pathscale.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>
2006-05-01[PATCH] vmsplice: allow user to pass in gift pagesJens Axboe
If SPLICE_F_GIFT is set, the user is basically giving this pages away to the kernel. That means we can steal them for eg page cache uses instead of copying it. The data must be properly page aligned and also a multiple of the page size in length. Signed-off-by: Jens Axboe <axboe@suse.de>
2006-05-01[PATCH] pipe: enable atomic copying of pipe data to/from user spaceJens Axboe
The pipe ->map() method uses kmap() to virtually map the pages, which is both slow and has known scalability issues on SMP. This patch enables atomic copying of pipe pages, by pre-faulting data and using kmap_atomic() instead. lmbench bw_pipe and lat_pipe measurements agree this is a Good Thing. Here are results from that on a UP machine with highmem (1.5GiB of RAM), running first a UP kernel, SMP kernel, and SMP kernel patched. Vanilla-UP: Pipe bandwidth: 1622.28 MB/sec Pipe bandwidth: 1610.59 MB/sec Pipe bandwidth: 1608.30 MB/sec Pipe latency: 7.3275 microseconds Pipe latency: 7.2995 microseconds Pipe latency: 7.3097 microseconds Vanilla-SMP: Pipe bandwidth: 1382.19 MB/sec Pipe bandwidth: 1317.27 MB/sec Pipe bandwidth: 1355.61 MB/sec Pipe latency: 9.6402 microseconds Pipe latency: 9.6696 microseconds Pipe latency: 9.6153 microseconds Patched-SMP: Pipe bandwidth: 1578.70 MB/sec Pipe bandwidth: 1579.95 MB/sec Pipe bandwidth: 1578.63 MB/sec Pipe latency: 9.1654 microseconds Pipe latency: 9.2266 microseconds Pipe latency: 9.1527 microseconds Signed-off-by: Jens Axboe <axboe@suse.de>