search for: __gfp_thisnode

...people might want is one that just tells how many of those MAX_ORDER-1 pages there are. See the thread in v33 with the subject "[PATCH v33 1/4] mm: add a function to get free page blocks" and look for me suggesting just using #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | __GFP_THISNODE | __GFP_NOMEMALLOC) struct page *page = alloc_pages(GFP_MINFLAGS, MAX_ORDER-1); for this all. But I could also see an argument for "allocate N pages of size MAX_ORDER-1", with some small N, simply because I can see the advantage of not taking and releasing the locking and looking...

...people might want is one that just tells how many of those MAX_ORDER-1 pages there are. See the thread in v33 with the subject "[PATCH v33 1/4] mm: add a function to get free page blocks" and look for me suggesting just using #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | __GFP_THISNODE | __GFP_NOMEMALLOC) struct page *page = alloc_pages(GFP_MINFLAGS, MAX_ORDER-1); for this all. But I could also see an argument for "allocate N pages of size MAX_ORDER-1", with some small N, simply because I can see the advantage of not taking and releasing the locking and looking...

On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: > > Would it be better to remove __GFP_THISNODE? We actually want to get all > the guest free pages (from all the nodes). Maybe. Or maybe it would be better to have the memory balloon logic be per-node? Maybe you don't want to remove too much memory from one node? I think it's one of those "play with it" things. I don'...

On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: > > Would it be better to remove __GFP_THISNODE? We actually want to get all > the guest free pages (from all the nodes). Maybe. Or maybe it would be better to have the memory balloon logic be per-node? Maybe you don't want to remove too much memory from one node? I think it's one of those "play with it" things. I don'...

...get_from_free_page_list > actually pop entries from the free list and use them as the buffer > to store PAs? Honestly, what I think the best option would be is to get rid of this interface *entirely*, and just have the balloon code do #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | __GFP_THISNODE | __GFP_NOMEMALLOC) struct page *page = alloc_pages(GFP_MINFLAGS, MAX_ORDER-1); which is not a new interface, and simply removes the max-order page from the list if at all possible. The above has the advantage of "just working", and not having any races. Now, because you don'...

...get_from_free_page_list > actually pop entries from the free list and use them as the buffer > to store PAs? Honestly, what I think the best option would be is to get rid of this interface *entirely*, and just have the balloon code do #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | __GFP_THISNODE | __GFP_NOMEMALLOC) struct page *page = alloc_pages(GFP_MINFLAGS, MAX_ORDER-1); which is not a new interface, and simply removes the max-order page from the list if at all possible. The above has the advantage of "just working", and not having any races. Now, because you don'...

On Thu 12-07-18 10:52:08, Wei Wang wrote: > On 07/12/2018 10:30 AM, Linus Torvalds wrote: > > On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: > > > Would it be better to remove __GFP_THISNODE? We actually want to get all > > > the guest free pages (from all the nodes). > > Maybe. Or maybe it would be better to have the memory balloon logic be > > per-node? Maybe you don't want to remove too much memory from one > > node? I think it's one of those &quot...

On Thu 12-07-18 10:52:08, Wei Wang wrote: > On 07/12/2018 10:30 AM, Linus Torvalds wrote: > > On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: > > > Would it be better to remove __GFP_THISNODE? We actually want to get all > > > the guest free pages (from all the nodes). > > Maybe. Or maybe it would be better to have the memory balloon logic be > > per-node? Maybe you don't want to remove too much memory from one > > node? I think it's one of those &quot...

...t; many of those MAX_ORDER-1 pages there are. > > See the thread in v33 with the subject > > "[PATCH v33 1/4] mm: add a function to get free page blocks" > > and look for me suggesting just using > > #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | > __GFP_THISNODE | __GFP_NOMEMALLOC) Would it be better to remove __GFP_THISNODE? We actually want to get all the guest free pages (from all the nodes). Best, Wei

...18 04:13 PM, Michal Hocko wrote: > > On Thu 12-07-18 10:52:08, Wei Wang wrote: > > > On 07/12/2018 10:30 AM, Linus Torvalds wrote: > > > > On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: > > > > > Would it be better to remove __GFP_THISNODE? We actually want to get all > > > > > the guest free pages (from all the nodes). > > > > Maybe. Or maybe it would be better to have the memory balloon logic be > > > > per-node? Maybe you don't want to remove too much memory from one > > > > n...

...ly pop entries from the free list and use them as the buffer > > to store PAs? > > Honestly, what I think the best option would be is to get rid of this > interface *entirely*, and just have the balloon code do > > #define GFP_MINFLAGS (__GFP_NORETRY | __GFP_NOWARN | > __GFP_THISNODE | __GFP_NOMEMALLOC) > > struct page *page = alloc_pages(GFP_MINFLAGS, MAX_ORDER-1); > > which is not a new interface, and simply removes the max-order page > from the list if at all possible. > > The above has the advantage of "just working", and not having a...

On 07/12/2018 10:30 AM, Linus Torvalds wrote: > On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: >> Would it be better to remove __GFP_THISNODE? We actually want to get all >> the guest free pages (from all the nodes). > Maybe. Or maybe it would be better to have the memory balloon logic be > per-node? Maybe you don't want to remove too much memory from one > node? I think it's one of those "play with it" t...

On 07/12/2018 04:13 PM, Michal Hocko wrote: > On Thu 12-07-18 10:52:08, Wei Wang wrote: >> On 07/12/2018 10:30 AM, Linus Torvalds wrote: >>> On Wed, Jul 11, 2018 at 7:17 PM Wei Wang <wei.w.wang at intel.com> wrote: >>>> Would it be better to remove __GFP_THISNODE? We actually want to get all >>>> the guest free pages (from all the nodes). >>> Maybe. Or maybe it would be better to have the memory balloon logic be >>> per-node? Maybe you don't want to remove too much memory from one >>> node? I think it's one of...

On Fri, Jun 15, 2018 at 2:08 PM Wei Wang <wei.w.wang at intel.com> wrote: > > This patch adds a function to get free pages blocks from a free page > list. The obtained free page blocks are hints about free pages, because > there is no guarantee that they are still on the free page list after > the function returns. Ack. This is the kind of simple interface where I don't

On Fri, Jun 15, 2018 at 2:08 PM Wei Wang <wei.w.wang at intel.com> wrote: > > This patch adds a function to get free pages blocks from a free page > list. The obtained free page blocks are hints about free pages, because > there is no guarantee that they are still on the free page list after > the function returns. Ack. This is the kind of simple interface where I don't

On Tue, Jul 10, 2018 at 6:24 PM Wei Wang <wei.w.wang at intel.com> wrote: > > We only get addresses of the "MAX_ORDER-1" blocks into the array. The > max size of the array that could be allocated by kmalloc is > KMALLOC_MAX_SIZE (i.e. 4MB on x86). With that max array, we could load > "4MB / sizeof(u64)" addresses of "MAX_ORDER-1" blocks, that is,

On Tue, Jul 10, 2018 at 6:24 PM Wei Wang <wei.w.wang at intel.com> wrote: > > We only get addresses of the "MAX_ORDER-1" blocks into the array. The > max size of the array that could be allocated by kmalloc is > KMALLOC_MAX_SIZE (i.e. 4MB on x86). With that max array, we could load > "4MB / sizeof(u64)" addresses of "MAX_ORDER-1" blocks, that is,

We have implemented hugepage support for guests in following manner In our implementation we added a parameter hugepage_num which is specified in the config file of the DomU. It is the number of hugepages that the guest is guaranteed to receive whenever the kernel asks for hugepage by using its boot time parameter or reserving after booting (eg. Using echo XX > /proc/sys/vm/nr_hugepages).