search for: copy_pages

I got curious how the lld produced gnu hash tables compared to gold. To test that I timed "perf record ninja check-llvm" (just the lit run) in a BUILD_SHARED_LIBS build. The performance was almost identical, so I decided to try sysv versus gnu (both produced by lld). The results are interesting: % grep -v '^#' perf-gnu/perf.report-by-dso-sym | head 38.77% ld-2.24.so

>>> Dan Magenheimer <dan.magenheimer@oracle.com> 13.01.09 00:29 >>> >I''m guessing the gcc optimizer for the memcpy code was tuned >for an Intel pipeline... Jan, were you measuring on an >AMD processor? Oh, actually my previous reply was without pushing my thinking fully back to what I was doing (and measuring) back then. I really measured on quad core

While looking at the origin of very frequently executed hypercalls I realized that the high page accessor functions in Linux would be good candidates to handle in the hypervisor - clearing or copying to/from a high page is a pretty frequent operation (provided there''s enough memory in the domain). While prior to the first submission I only measured kernel builds (where the results are not

While looking at the origin of very frequently executed hypercalls (as usual, kernel builds are what''s being measured), I realized that the high page accessor functions in Linux would be good candidates to handle in the hypervisor - clearing or copying to/from a high page is a pretty frequent operation (provided there''s enough memory). However, the measured results

On Tue, Mar 12, 2019 at 01:53:37PM -0700, James Bottomley wrote: > I've got to say: optimize what? What code do we ever have in the > kernel that kmap's a page and then doesn't do anything with it? You can > guarantee that on kunmap the page is either referenced (needs > invalidating) or updated (needs flushing). The in-kernel use of kmap is > always > > kmap

Assumes hypervisor interface headers have been sync-ed after the hypervisor side patch was applied. As usual, written and tested on 2.6.27.3 and made apply to the 2.6.18 tree without further testing. Signed-off-by: Jan Beulich <jbeulich@novell.com> Index: head-2008-10-24/arch/i386/mm/highmem-xen.c =================================================================== ---

On 2019/3/11 ??9:43, Andrea Arcangeli wrote: > On Mon, Mar 11, 2019 at 08:48:37AM -0400, Michael S. Tsirkin wrote: >> Using copyXuser is better I guess. > It certainly would be faster there, but I don't think it's needed if > that would be the only use case left that justifies supporting two > different models. On small 32bit systems with little RAM kmap won't >

Hi gang, Here''s some trivial cleanups that I''ve built up while reading through the code. They''ve been run through xfstests -g quick. - z -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html

This change updates a few of the functions to use __pa_symbol when translating C visible symbols instead of __pa. By using __pa_symbol we are able to drop a few extra lines of code as don't have to test to see if the virtual pointer is a part of the kernel text or just standard virtual memory. Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Signed-off-by: Alexander Duyck

This change updates a few of the functions to use __pa_symbol when translating C visible symbols instead of __pa. By using __pa_symbol we are able to drop a few extra lines of code as don't have to test to see if the virtual pointer is a part of the kernel text or just standard virtual memory. Cc: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com> Signed-off-by: Alexander Duyck

On Mon, Mar 11, 2019 at 08:48:37AM -0400, Michael S. Tsirkin wrote: > Using copyXuser is better I guess. It certainly would be faster there, but I don't think it's needed if that would be the only use case left that justifies supporting two different models. On small 32bit systems with little RAM kmap won't perform measurably different on 32bit or 64bit systems. If the 32bit host

On Tue, Mar 12, 2019 at 02:19:15PM -0700, James Bottomley wrote: > I mean in the sequence > > flush_dcache_page(page); > flush_dcache_page(page); > > The first flush_dcache_page did all the work and the second it a > tightly pipelined no-op. That's what I mean by there not really being > a double hit. Ok I wasn't sure it was clear there was a double (profiling)

On Tue, Mar 12, 2019 at 10:59:09AM +0800, Jason Wang wrote: > > On 2019/3/12 ??2:14, David Miller wrote: > > From: "Michael S. Tsirkin" <mst at redhat.com> > > Date: Mon, 11 Mar 2019 09:59:28 -0400 > > > > > On Mon, Mar 11, 2019 at 03:13:17PM +0800, Jason Wang wrote: > > > > On 2019/3/8 ??10:12, Christoph Hellwig wrote: > > >

On Tue, Mar 12, 2019 at 10:59:09AM +0800, Jason Wang wrote: > > On 2019/3/12 ??2:14, David Miller wrote: > > From: "Michael S. Tsirkin" <mst at redhat.com> > > Date: Mon, 11 Mar 2019 09:59:28 -0400 > > > > > On Mon, Mar 11, 2019 at 03:13:17PM +0800, Jason Wang wrote: > > > > On 2019/3/8 ??10:12, Christoph Hellwig wrote: > > >

On Thu, Jan 14, 2016 at 04:47:53PM -0800, Paul E. McKenney wrote: > So you need to build a different kernel for some types of MIPS systems? Yes. We can't really do without. Classic MIPS code is not relocatable without the complexity of PIC code as used by ELF DSOs - and their performanc penalty. Plus we have a number of architecture revisions ovr the decades, big and little endian, 32

On Thu, Jan 14, 2016 at 04:47:53PM -0800, Paul E. McKenney wrote: > So you need to build a different kernel for some types of MIPS systems? Yes. We can't really do without. Classic MIPS code is not relocatable without the complexity of PIC code as used by ELF DSOs - and their performanc penalty. Plus we have a number of architecture revisions ovr the decades, big and little endian, 32

tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/mst/vhost.git linux-next head: c5db5a8d998da36ada7287aa53b4ed501a0a2b2b commit: b1b0d638e6f93b91cf34585350bb00035d066989 [13/15] mm: Introduce Reported pages config: ia64-defconfig (attached as .config) compiler: ia64-linux-gcc (GCC) 7.4.0 reproduce: wget

On Mon, Mar 11, 2019 at 03:40:31PM +0800, Jason Wang wrote: > > On 2019/3/9 ??3:48, Andrea Arcangeli wrote: > > Hello Jeson, > > > > On Fri, Mar 08, 2019 at 04:50:36PM +0800, Jason Wang wrote: > > > Just to make sure I understand here. For boosting through huge TLB, do > > > you mean we can do that in the future (e.g by mapping more userspace > >

On Mon, Mar 11, 2019 at 03:40:31PM +0800, Jason Wang wrote: > > On 2019/3/9 ??3:48, Andrea Arcangeli wrote: > > Hello Jeson, > > > > On Fri, Mar 08, 2019 at 04:50:36PM +0800, Jason Wang wrote: > > > Just to make sure I understand here. For boosting through huge TLB, do > > > you mean we can do that in the future (e.g by mapping more userspace > >

The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner <tglx at linutronix.de> Cc: Andrew Morton <akpm at linux-foundation.org> Cc: linux-mm at kvack.org --- V3: Do not reuse the kmap_atomic_idx pile and use kmap_size.h right