search for: pagefault

...s more time than lame to encode a file. (text report from my script is appende later in this mail) DECODE SPEED: ------------- OK.. not speed.. CPU usage :-) on a K6-188 -> ogg123: 176.56user 1.44system 5:01.00elapsed 59%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (1229major+280minor)pagefaults 0swaps -> mpg123: 50.57user 3.50system 5:00.65elapsed 17%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (2396major+116minor)pagefaults 30swaps COMMENTS: ---------- For Alpha software Ogg/Vorbis is great. OGG size is comparable to MP3 size (will this improve?), OGG encode speed is compa...

...s more time than lame to encode a file. (text report from my script is appende later in this mail) DECODE SPEED: ------------- OK.. not speed.. CPU usage :-) on a K6-188 -> ogg123: 176.56user 1.44system 5:01.00elapsed 59%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (1229major+280minor)pagefaults 0swaps -> mpg123: 50.57user 3.50system 5:00.65elapsed 17%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (2396major+116minor)pagefaults 30swaps COMMENTS: ---------- For Alpha software Ogg/Vorbis is great. OGG size is comparable to MP3 size (will this improve?), OGG encode speed is compa...

Regarding the presentation I gave at the kvm forum on pagefaults. Two points: 1. pagefaults are important not just for migration. They are important for performance features such as autonuma and huge pages, since this relies on moving pages around. Migration can maybe be solved by switch to software but this is not a good solution for numa and thp since at...

...rtions(+), 0 deletions(-) create mode 100644 llvm/dummy bash-4.1$ /usr/bin/time git log --no-color -z --pretty=raw --show-notes --parents --boundary HEAD -- dummy > /dev/null 198.37user 0.40system 3:18.67elapsed 100%CPU (0avgtext+0avgdata 696456maxresident)k 0inputs+0outputs (0major+175765minor)pagefaults 0swaps But also when examining older files, here are some tests using the monorepo: bash-4.1$ git clone https://github.com/llvm/llvm-project.git llvm-project bash-4.1$ cd llvm-project bash-4.1$ /usr/bin/time git log --no-color -z --pretty=raw --show-notes --parents --boundary HEAD > /dev/nu...

...le but, again, it only speaks > about the relative sizes of LLVM/Cray's compiler. Ok, here are some hard numbers for empty builds: LLVM empty build: /usr/bin/time make -j16 4.32user 2.47system 0:03.21elapsed 211%CPU (0avgtext+0avgdata 13376maxresident)k 0inputs+0outputs (0major+671804minor)pagefaults 0swaps Cray empty build: /usr/bin/time make dynamic-developer -j16 2.88user 1.06system 0:04.94elapsed 79%CPU (0avgtext+0avgdata 64208maxresident)k 0inputs+0outputs (0major+184605minor)pagefaults 0swaps The Cray empty build includes some really horrendous shell script trickery known as "modu...

Nico Weber <thakis at chromium.org> writes: > On Tue, Nov 1, 2011 at 3:09 PM, David A. Greene <greened at obbligato.org> wrote: >> Óscar Fuentes <ofv at wanadoo.es> writes: >> >>> Okay, we can get rid of recursive make. However, as pointed out >>> elsewhere, removing recursive make will not make a difference on the >>> LLVM build. What

...between SIPI/INIT and trying to execute the first trampoline instruction. The race condition results in a CMCI complaining about a parity error in an instruction cache is delivered to Xen as soon as the SMI handler returns. On Xen-3.x, the CMCI handler dereferences the dom0 pointer, resulting in a pagefault at this point in boot. Intel are working to track down why the CMCI is occurring in the first place, but as it is apparently benign, Xen should continue to boot regardless. This error does not affect Xen-4.x, as it correctly checks that the dom0 pointer is not null before trying to use it. -- A...

...ing, but marking for update) atimes in mmap(). I think to be strictly correct, setting of atimes should be nearer to munmap(2) than mmap(). No read has occurred from userland's viewpoint at mmap() time. However, since the OS can't tell if applications read mmapped memory unless their is a pagefault, the atime would have to be set on every pagefault to be as correct as possible, and I think mmap() prefaults some pages so it would have to set the atime whether or not the application reads the pages. So I think setting atimes in mmap() is required in practice. This leaves the problem that late...

...d the map of the incoming task are restored. That's obviously slow, but highmem is slow anyway. The kmap_local.*() functions can be invoked from both preemptible and atomic context. kmap local sections disable migration to keep the resulting virtual mapping address correct, but disable neither pagefaults nor preemption. A wholesale conversion of kmap_atomic to be fully preemptible is not possible because some of the usage sites might rely on the preemption disable for serialization or on the implicit pagefault disable. Needs to be done on a case by case basis. Signed-off-by: Thomas Gleixner <...

https://bugs.freedesktop.org/show_bug.cgi?id=98506 Bug ID: 98506 Summary: Pagefault in gf100_vm_flush Product: xorg Version: git Hardware: Other OS: All Status: NEW Severity: normal Priority: medium Component: Driver/nouveau Assignee: nouveau at lists.freedesktop.org Report...

On Tue, Nov 01, 2011 at 06:27:35PM -0500, David A. Greene wrote: > Here is actual data comparing an empty LLVM build done recursively (the > LLVM build) and non-recursively (the Cray build). > > See this? > > 0inputs+0outputs (0major+671804minor)pagefaults 0swaps > > vs. this? > > 0inputs+0outputs (0major+184605minor)pagefaults 0swaps > > That's I/O. Sorry to disappoint you, but no, this isn't I/O. You have just shown that a LLVM build touches more mmap'd pages. Joerg

OS: Mandriva 2006 LE w/KDE System: dual boot (WinXP/Linux) running on separate HD, 1.5GHz Intel, 512MRAM I have installed and uninstalled Wine 9.14 and 9.15. I have tried to install several applications (wine setup.exe") and use the supplimental applications (wineconfig, filemanager, etc.). They seem to work and the installs complete Unfortunately, that's where the good luck ends.

...g a new 3 GB (1024 x 3megabytes blocks) file with dd needs 10.18 sec wallclock time: taskset 1 time dd if=/dev/zero bs=3M count=1024 of=~backes/xxxxx 1024+0 records in 1024+0 records out 0.00user 10.02system 0:10.18elapsed 98%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+187minor)pagefaults 0swaps 2. Repeating the same for 3 times: taskset 1 time dd if=/dev/zero bs=3M count=1024 of=~backes/xxxxx 1024+0 records in 1024+0 records out 0.00user 11.88system 1:05.26elapsed 18%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (0major+187minor)pagefaults 0swaps taskset 1 time dd if...

greened at obbligato.org (David A. Greene) writes: > Ok, here are some hard numbers for empty builds: > > LLVM empty build: > /usr/bin/time make -j16 > 4.32user 2.47system 0:03.21elapsed 211%CPU (0avgtext+0avgdata 13376maxresident)k > 0inputs+0outputs (0major+671804minor)pagefaults 0swaps So your 16-way machine takes 2.5 times more than my 4-way cheap desktop... > Cray empty build: > /usr/bin/time make dynamic-developer -j16 > 2.88user 1.06system 0:04.94elapsed 79%CPU (0avgtext+0avgdata 64208maxresident)k > 0inputs+0outputs (0major+184605minor)pagefaults 0swaps...

Hi All, I have several questions about log dirty mode during live migration. For my understanding, each time after XEN_DOMCTL_SHADOW_OP_CLEAN or XEN_DOMCTL_SHADOW_OP_PEEK operation, all the pages are set as read only. The following memory accesses to the memory pages will cause page fault (permission conflict) then using page_mark_dirty function to set the dirty bitmap. However, after I read

On 2019/5/9 ??9:18, Michael S. Tsirkin wrote: > On Thu, May 09, 2019 at 08:58:00AM -0400, Jason Wang wrote: >> Vhost log dirty pages directly to a userspace bitmap through GUP and >> kmap_atomic() since kernel doesn't have a set_bit_to_user() >> helper. This will cause issues for the arch that has virtually tagged >> caches. The way to fix is to keep using userspace

On 2019/5/9 ??9:18, Michael S. Tsirkin wrote: > On Thu, May 09, 2019 at 08:58:00AM -0400, Jason Wang wrote: >> Vhost log dirty pages directly to a userspace bitmap through GUP and >> kmap_atomic() since kernel doesn't have a set_bit_to_user() >> helper. This will cause issues for the arch that has virtually tagged >> caches. The way to fix is to keep using userspace

Olly Betts writes: > On Sun, Apr 10, 2016 at 04:47:01PM +0200, Jean-Francois Dockes wrote: > > Some might notice the 50% index size increase. Excessive index size is > > already one relatively rare, but recurring complaint. Except if I did > > something wrong: I'm actually quite surprised by it. > > Did you try compacting the resulting databases? > >

...fs/file.c +++ b/fs/btrfs/file.c @@ -57,15 +57,11 @@ static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, PAGE_CACHE_SIZE - offset, write_bytes); struct page *page = prepared_pages[pg]; again: - /* - * Copy data from userspace to the current page - * - * Disable pagefault to avoid recursive lock since the pages - * are already locked - */ - pagefault_disable(); - copied = iov_iter_copy_from_user_atomic(page, i, offset, count); - pagefault_enable(); + if (unlikely(iov_iter_fault_in_readable(i, count))) + return -EFAULT; + + /* Copy data from userspace to...

...vel allocator for malloc but it doesn't. It uses sbrk() mostly for small (<128k) allocations, and even with mmaps it caches them for a while. I think that is because mmap() is slow in multithreaded apps, since it needs to take a process level lock, which also contends with the lock taken by pagefaults from other existing mmaps (in fact that lock is held during disk I/O!). Best regards, --Edwin