search for: arch_alloc_pages

On 20.06.2017 18:44, Rik van Riel wrote: > On Mon, 2017-06-12 at 07:10 -0700, Dave Hansen wrote: > >> The hypervisor is going to throw away the contents of these pages, >> right? As soon as the spinlock is released, someone can allocate a >> page, and put good data in it. What keeps the hypervisor from >> throwing >> away good data? > > That looks like

On 20.06.2017 18:44, Rik van Riel wrote: > On Mon, 2017-06-12 at 07:10 -0700, Dave Hansen wrote: > >> The hypervisor is going to throw away the contents of these pages, >> right? As soon as the spinlock is released, someone can allocate a >> page, and put good data in it. What keeps the hypervisor from >> throwing >> away good data? > > That looks like

On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote: > > On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > > > > > > > > > > > > > > > + if (!arrays) > > > > > + return NULL; > > > > > + > > > > > + for (i = 0; i <

On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote: > > On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > > > > > > > > > > > > > > > + if (!arrays) > > > > > + return NULL; > > > > > + > > > > > + for (i = 0; i <

On Wed, Jun 27, 2018 at 09:24:18AM +0800, Wei Wang wrote: > On 06/26/2018 09:34 PM, Michael S. Tsirkin wrote: > > On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > > > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote: > > > > On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > > > > > > > > > > > + if (!arrays) >

On Wed, Jun 27, 2018 at 09:24:18AM +0800, Wei Wang wrote: > On 06/26/2018 09:34 PM, Michael S. Tsirkin wrote: > > On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > > > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote: > > > > On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > > > > > > > > > > > + if (!arrays) >

...low path, which: > 2a) Iterates over the set of freed pages, and > 2b) Checks whether they are still free, and > 2c) Adds the still free pages to a list that is > to be passed to the hypervisor, to be MADV_FREEd. > 2d) Makes that hypercall. > > Meanwhile all arch_alloc_pages has to do is make sure it > does not allocate a page while it is currently being > MADV_FREEd on the hypervisor side. > > The code Wei is working on looks like it could be > suitable for steps (2c) and (2d) above. Nitesh already > has code for steps 1 through 2b. > > --...

...low path, which: > 2a) Iterates over the set of freed pages, and > 2b) Checks whether they are still free, and > 2c) Adds the still free pages to a list that is > to be passed to the hypervisor, to be MADV_FREEd. > 2d) Makes that hypercall. > > Meanwhile all arch_alloc_pages has to do is make sure it > does not allocate a page while it is currently being > MADV_FREEd on the hypervisor side. > > The code Wei is working on looks like it could be > suitable for steps (2c) and (2d) above. Nitesh already > has code for steps 1 through 2b. > > --...

On Wed, Jun 27, 2018 at 11:00:05AM +0800, Wei Wang wrote: > On 06/27/2018 10:41 AM, Michael S. Tsirkin wrote: > > On Wed, Jun 27, 2018 at 09:24:18AM +0800, Wei Wang wrote: > > > On 06/26/2018 09:34 PM, Michael S. Tsirkin wrote: > > > > On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > > > > > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote:

On Wed, Jun 27, 2018 at 11:00:05AM +0800, Wei Wang wrote: > On 06/27/2018 10:41 AM, Michael S. Tsirkin wrote: > > On Wed, Jun 27, 2018 at 09:24:18AM +0800, Wei Wang wrote: > > > On 06/26/2018 09:34 PM, Michael S. Tsirkin wrote: > > > > On Tue, Jun 26, 2018 at 08:27:44PM +0800, Wei Wang wrote: > > > > > On 06/26/2018 11:56 AM, Michael S. Tsirkin wrote:

On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > On 06/26/2018 09:37 AM, Michael S. Tsirkin wrote: > > On Mon, Jun 25, 2018 at 08:05:10PM +0800, Wei Wang wrote: > > > > > @@ -326,17 +353,6 @@ static void stats_handle_request(struct virtio_balloon *vb) > > > virtqueue_kick(vq); > > > } > > > -static void virtballoon_changed(struct

On Tue, Jun 26, 2018 at 11:46:35AM +0800, Wei Wang wrote: > On 06/26/2018 09:37 AM, Michael S. Tsirkin wrote: > > On Mon, Jun 25, 2018 at 08:05:10PM +0800, Wei Wang wrote: > > > > > @@ -326,17 +353,6 @@ static void stats_handle_request(struct virtio_balloon *vb) > > > virtqueue_kick(vq); > > > } > > > -static void virtballoon_changed(struct

On 20.06.2017 20:17, Michael S. Tsirkin wrote: > On Tue, Jun 20, 2017 at 06:49:33PM +0200, David Hildenbrand wrote: >> On 20.06.2017 18:44, Rik van Riel wrote: >>> On Mon, 2017-06-12 at 07:10 -0700, Dave Hansen wrote: >>> >>>> The hypervisor is going to throw away the contents of these pages, >>>> right? As soon as the spinlock is released,

On 20.06.2017 20:17, Michael S. Tsirkin wrote: > On Tue, Jun 20, 2017 at 06:49:33PM +0200, David Hildenbrand wrote: >> On 20.06.2017 18:44, Rik van Riel wrote: >>> On Mon, 2017-06-12 at 07:10 -0700, Dave Hansen wrote: >>> >>>> The hypervisor is going to throw away the contents of these pages, >>>> right? As soon as the spinlock is released,

Please stop cc'ing me on things also sent to closed mailing lists (virtio-dev at lists.oasis-open.org). I'm happy to review things on open lists, but I'm not fond of the closed lists bouncing things at me. On 06/09/2017 03:41 AM, Wei Wang wrote: > Add a function to find a page block on the free list specified by the > caller. Pages from the page block may be used immediately

Please stop cc'ing me on things also sent to closed mailing lists (virtio-dev at lists.oasis-open.org). I'm happy to review things on open lists, but I'm not fond of the closed lists bouncing things at me. On 06/09/2017 03:41 AM, Wei Wang wrote: > Add a function to find a page block on the free list specified by the > caller. Pages from the page block may be used immediately

...red > a very special corner case that I would argue is not worth it to be > optimized. > > If I am missing something important here, sorry in advance :) > Probably I didn't explain that well. Please see my re-try: That work is to monitor page allocation and free activities via arch_alloc_pages and arch_free_pages. It has per-CPU lists to record the pages that are freed to the mm free list, and the per-CPU lists dump the recorded pages to a global list when any of them is full. So its own per-CPU list will only be able to get free pages when there is an mm free() function gets called....

...red > a very special corner case that I would argue is not worth it to be > optimized. > > If I am missing something important here, sorry in advance :) > Probably I didn't explain that well. Please see my re-try: That work is to monitor page allocation and free activities via arch_alloc_pages and arch_free_pages. It has per-CPU lists to record the pages that are freed to the mm free list, and the per-CPU lists dump the recorded pages to a global list when any of them is full. So its own per-CPU list will only be able to get free pages when there is an mm free() function gets called....

On Mon, 2017-06-12 at 07:10 -0700, Dave Hansen wrote: > The hypervisor is going to throw away the contents of these pages, > right???As soon as the spinlock is released, someone can allocate a > page, and put good data in it.??What keeps the hypervisor from > throwing > away good data? That looks like it may be the wrong API, then? We already have hooks called arch_free_page and

...l, arch_free_pages goes into a slow path, which: 2a) Iterates over the set of freed pages, and 2b) Checks whether they are still free, and 2c) Adds the still free pages to a list that is to be passed to the hypervisor, to be MADV_FREEd. 2d) Makes that hypercall. Meanwhile all arch_alloc_pages has to do is make sure it does not allocate a page while it is currently being MADV_FREEd on the hypervisor side. The code Wei is working on looks like it could be suitable for steps (2c) and (2d) above. Nitesh already has code for steps 1 through 2b. -- All rights reversed -------------- next...