| Message ID | 20240827190916.34242-1-urezki@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: vmalloc: Refactor vm_area_alloc_pages() function | expand |
On Tue 27-08-24 21:09:16, Uladzislau Rezki wrote: > The aim is to simplify and making the vm_area_alloc_pages() > function less confusing as it became more clogged nowadays: > > - eliminate a "bulk_gfp" variable and do not overwrite a gfp > flag for bulk allocator; > - drop __GFP_NOFAIL flag for high-order-page requests on upper > layer. It becomes less spread between levels when it comes to > __GFP_NOFAIL allocations; > - add a comment about a fallback path if high-order attempt is > unsuccessful because for such cases __GFP_NOFAIL is dropped; > - fix a typo in a commit message. > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Thanks! > --- > mm/vmalloc.c | 37 +++++++++++++++++-------------------- > 1 file changed, 17 insertions(+), 20 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 3f9b6bd707d2..57862865e808 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > unsigned int order, unsigned int nr_pages, struct page **pages) > { > unsigned int nr_allocated = 0; > - gfp_t alloc_gfp = gfp; > - bool nofail = gfp & __GFP_NOFAIL; > struct page *page; > int i; > > @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * more permissive. > */ > if (!order) { > - /* bulk allocator doesn't support nofail req. officially */ > - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; > - > while (nr_allocated < nr_pages) { > unsigned int nr, nr_pages_request; > > @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * but mempolicy wants to alloc memory by interleaving. > */ > if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) > - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, > + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, > nr_pages_request, > pages + nr_allocated); > - > else > - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, > + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, > nr_pages_request, > pages + nr_allocated); > > @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > if (nr != nr_pages_request) > break; > } > - } else if (gfp & __GFP_NOFAIL) { > - /* > - * Higher order nofail allocations are really expensive and > - * potentially dangerous (pre-mature OOM, disruptive reclaim > - * and compaction etc. > - */ > - alloc_gfp &= ~__GFP_NOFAIL; > } > > /* High-order pages or fallback path if "bulk" fails. */ > while (nr_allocated < nr_pages) { > - if (!nofail && fatal_signal_pending(current)) > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) > break; > > if (nid == NUMA_NO_NODE) > - page = alloc_pages_noprof(alloc_gfp, order); > + page = alloc_pages_noprof(gfp, order); > else > - page = alloc_pages_node_noprof(nid, alloc_gfp, order); > + page = alloc_pages_node_noprof(nid, gfp, order); > + > if (unlikely(!page)) > break; > > /* > * Higher order allocations must be able to be treated as > - * indepdenent small pages by callers (as they can with > + * independent small pages by callers (as they can with > * small-page vmallocs). Some drivers do their own refcounting > * on vmalloc_to_page() pages, some use page->mapping, > * page->lru, etc. > @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > set_vm_area_page_order(area, page_shift - PAGE_SHIFT); > page_order = vm_area_page_order(area); > > - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, > + /* > + * Higher order nofail allocations are really expensive and > + * potentially dangerous (pre-mature OOM, disruptive reclaim > + * and compaction etc. > + * > + * Please note, the __vmalloc_node_range_noprof() falls-back > + * to order-0 pages if high-order attempt is unsuccessful. > + */ > + area->nr_pages = vm_area_alloc_pages((page_order ? > + gfp_mask & ~__GFP_NOFAIL : gfp_mask) | __GFP_NOWARN, > node, page_order, nr_small_pages, area->pages); > > atomic_long_add(area->nr_pages, &nr_vmalloc_pages); > -- > 2.39.2
On 08/27/24 at 09:09pm, Uladzislau Rezki (Sony) wrote: > The aim is to simplify and making the vm_area_alloc_pages() > function less confusing as it became more clogged nowadays: > > - eliminate a "bulk_gfp" variable and do not overwrite a gfp > flag for bulk allocator; > - drop __GFP_NOFAIL flag for high-order-page requests on upper > layer. It becomes less spread between levels when it comes to > __GFP_NOFAIL allocations; > - add a comment about a fallback path if high-order attempt is > unsuccessful because for such cases __GFP_NOFAIL is dropped; > - fix a typo in a commit message. > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > --- > mm/vmalloc.c | 37 +++++++++++++++++-------------------- > 1 file changed, 17 insertions(+), 20 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 3f9b6bd707d2..57862865e808 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > unsigned int order, unsigned int nr_pages, struct page **pages) > { > unsigned int nr_allocated = 0; > - gfp_t alloc_gfp = gfp; > - bool nofail = gfp & __GFP_NOFAIL; > struct page *page; > int i; > > @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * more permissive. > */ > if (!order) { > - /* bulk allocator doesn't support nofail req. officially */ > - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; > - > while (nr_allocated < nr_pages) { > unsigned int nr, nr_pages_request; > > @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > * but mempolicy wants to alloc memory by interleaving. > */ > if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) > - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, > + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, > nr_pages_request, > pages + nr_allocated); > - > else > - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, > + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, > nr_pages_request, > pages + nr_allocated); > > @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > if (nr != nr_pages_request) > break; > } > - } else if (gfp & __GFP_NOFAIL) { > - /* > - * Higher order nofail allocations are really expensive and > - * potentially dangerous (pre-mature OOM, disruptive reclaim > - * and compaction etc. > - */ > - alloc_gfp &= ~__GFP_NOFAIL; > } > > /* High-order pages or fallback path if "bulk" fails. */ > while (nr_allocated < nr_pages) { > - if (!nofail && fatal_signal_pending(current)) > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) > break; > > if (nid == NUMA_NO_NODE) > - page = alloc_pages_noprof(alloc_gfp, order); > + page = alloc_pages_noprof(gfp, order); > else > - page = alloc_pages_node_noprof(nid, alloc_gfp, order); > + page = alloc_pages_node_noprof(nid, gfp, order); > + > if (unlikely(!page)) > break; > > /* > * Higher order allocations must be able to be treated as > - * indepdenent small pages by callers (as they can with > + * independent small pages by callers (as they can with > * small-page vmallocs). Some drivers do their own refcounting > * on vmalloc_to_page() pages, some use page->mapping, > * page->lru, etc. > @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > set_vm_area_page_order(area, page_shift - PAGE_SHIFT); > page_order = vm_area_page_order(area); > > - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, > + /* > + * Higher order nofail allocations are really expensive and ~~~~~~~~~~~~ Seems we use both higher-order and high-order to describe the non 0-order pages in many places. I personally would take high-order, higher-order seems to be a little confusing because it's not explicit what is compared with and lower. Surely this is not an issue to this patch, I see a lot of 'higher order' in kernel codes. For this patch, Reviewed-by: Baoquan He <bhe@redhat.com> > + * potentially dangerous (pre-mature OOM, disruptive reclaim > + * and compaction etc. > + * > + * Please note, the __vmalloc_node_range_noprof() falls-back > + * to order-0 pages if high-order attempt is unsuccessful. > + */ > + area->nr_pages = vm_area_alloc_pages((page_order ? > + gfp_mask & ~__GFP_NOFAIL : gfp_mask) | __GFP_NOWARN, > node, page_order, nr_small_pages, area->pages); > > atomic_long_add(area->nr_pages, &nr_vmalloc_pages); > -- > 2.39.2 >
On Thu, Aug 29, 2024 at 11:48:32AM +0800, Baoquan He wrote: > On 08/27/24 at 09:09pm, Uladzislau Rezki (Sony) wrote: > > The aim is to simplify and making the vm_area_alloc_pages() > > function less confusing as it became more clogged nowadays: > > > > - eliminate a "bulk_gfp" variable and do not overwrite a gfp > > flag for bulk allocator; > > - drop __GFP_NOFAIL flag for high-order-page requests on upper > > layer. It becomes less spread between levels when it comes to > > __GFP_NOFAIL allocations; > > - add a comment about a fallback path if high-order attempt is > > unsuccessful because for such cases __GFP_NOFAIL is dropped; > > - fix a typo in a commit message. > > > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > > --- > > mm/vmalloc.c | 37 +++++++++++++++++-------------------- > > 1 file changed, 17 insertions(+), 20 deletions(-) > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > index 3f9b6bd707d2..57862865e808 100644 > > --- a/mm/vmalloc.c > > +++ b/mm/vmalloc.c > > @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > unsigned int order, unsigned int nr_pages, struct page **pages) > > { > > unsigned int nr_allocated = 0; > > - gfp_t alloc_gfp = gfp; > > - bool nofail = gfp & __GFP_NOFAIL; > > struct page *page; > > int i; > > > > @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > * more permissive. > > */ > > if (!order) { > > - /* bulk allocator doesn't support nofail req. officially */ > > - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; > > - > > while (nr_allocated < nr_pages) { > > unsigned int nr, nr_pages_request; > > > > @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > * but mempolicy wants to alloc memory by interleaving. > > */ > > if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) > > - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, > > + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, > > nr_pages_request, > > pages + nr_allocated); > > - > > else > > - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, > > + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, > > nr_pages_request, > > pages + nr_allocated); > > > > @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > if (nr != nr_pages_request) > > break; > > } > > - } else if (gfp & __GFP_NOFAIL) { > > - /* > > - * Higher order nofail allocations are really expensive and > > - * potentially dangerous (pre-mature OOM, disruptive reclaim > > - * and compaction etc. > > - */ > > - alloc_gfp &= ~__GFP_NOFAIL; > > } > > > > /* High-order pages or fallback path if "bulk" fails. */ > > while (nr_allocated < nr_pages) { > > - if (!nofail && fatal_signal_pending(current)) > > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) > > break; > > > > if (nid == NUMA_NO_NODE) > > - page = alloc_pages_noprof(alloc_gfp, order); > > + page = alloc_pages_noprof(gfp, order); > > else > > - page = alloc_pages_node_noprof(nid, alloc_gfp, order); > > + page = alloc_pages_node_noprof(nid, gfp, order); > > + > > if (unlikely(!page)) > > break; > > > > /* > > * Higher order allocations must be able to be treated as > > - * indepdenent small pages by callers (as they can with > > + * independent small pages by callers (as they can with > > * small-page vmallocs). Some drivers do their own refcounting > > * on vmalloc_to_page() pages, some use page->mapping, > > * page->lru, etc. > > @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > > set_vm_area_page_order(area, page_shift - PAGE_SHIFT); > > page_order = vm_area_page_order(area); > > > > - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, > > + /* > > + * Higher order nofail allocations are really expensive and > ~~~~~~~~~~~~ > Seems we use both higher-order and high-order to describe the > non 0-order pages in many places. I personally would take high-order, > higher-order seems to be a little confusing because it's not explicit > what is compared with and lower. > > Surely this is not an issue to this patch, I see a lot of 'higher order' > in kernel codes. > I agree. It sounds like hard to figure out the difference between both. Are you willing send the patch? If not, i can send it out :) > For this patch, > > Reviewed-by: Baoquan He <bhe@redhat.com> > Thanks! -- Uladzislau Rezki
On 08/29/24 at 10:12am, Uladzislau Rezki wrote: > On Thu, Aug 29, 2024 at 11:48:32AM +0800, Baoquan He wrote: > > On 08/27/24 at 09:09pm, Uladzislau Rezki (Sony) wrote: > > > The aim is to simplify and making the vm_area_alloc_pages() > > > function less confusing as it became more clogged nowadays: > > > > > > - eliminate a "bulk_gfp" variable and do not overwrite a gfp > > > flag for bulk allocator; > > > - drop __GFP_NOFAIL flag for high-order-page requests on upper > > > layer. It becomes less spread between levels when it comes to > > > __GFP_NOFAIL allocations; > > > - add a comment about a fallback path if high-order attempt is > > > unsuccessful because for such cases __GFP_NOFAIL is dropped; > > > - fix a typo in a commit message. > > > > > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > > > --- > > > mm/vmalloc.c | 37 +++++++++++++++++-------------------- > > > 1 file changed, 17 insertions(+), 20 deletions(-) > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > index 3f9b6bd707d2..57862865e808 100644 > > > --- a/mm/vmalloc.c > > > +++ b/mm/vmalloc.c > > > @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > unsigned int order, unsigned int nr_pages, struct page **pages) > > > { > > > unsigned int nr_allocated = 0; > > > - gfp_t alloc_gfp = gfp; > > > - bool nofail = gfp & __GFP_NOFAIL; > > > struct page *page; > > > int i; > > > > > > @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > * more permissive. > > > */ > > > if (!order) { > > > - /* bulk allocator doesn't support nofail req. officially */ > > > - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; > > > - > > > while (nr_allocated < nr_pages) { > > > unsigned int nr, nr_pages_request; > > > > > > @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > * but mempolicy wants to alloc memory by interleaving. > > > */ > > > if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) > > > - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, > > > + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, > > > nr_pages_request, > > > pages + nr_allocated); > > > - > > > else > > > - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, > > > + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, > > > nr_pages_request, > > > pages + nr_allocated); > > > > > > @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > if (nr != nr_pages_request) > > > break; > > > } > > > - } else if (gfp & __GFP_NOFAIL) { > > > - /* > > > - * Higher order nofail allocations are really expensive and > > > - * potentially dangerous (pre-mature OOM, disruptive reclaim > > > - * and compaction etc. > > > - */ > > > - alloc_gfp &= ~__GFP_NOFAIL; > > > } > > > > > > /* High-order pages or fallback path if "bulk" fails. */ > > > while (nr_allocated < nr_pages) { > > > - if (!nofail && fatal_signal_pending(current)) > > > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) > > > break; > > > > > > if (nid == NUMA_NO_NODE) > > > - page = alloc_pages_noprof(alloc_gfp, order); > > > + page = alloc_pages_noprof(gfp, order); > > > else > > > - page = alloc_pages_node_noprof(nid, alloc_gfp, order); > > > + page = alloc_pages_node_noprof(nid, gfp, order); > > > + > > > if (unlikely(!page)) > > > break; > > > > > > /* > > > * Higher order allocations must be able to be treated as > > > - * indepdenent small pages by callers (as they can with > > > + * independent small pages by callers (as they can with > > > * small-page vmallocs). Some drivers do their own refcounting > > > * on vmalloc_to_page() pages, some use page->mapping, > > > * page->lru, etc. > > > @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > > > set_vm_area_page_order(area, page_shift - PAGE_SHIFT); > > > page_order = vm_area_page_order(area); > > > > > > - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, > > > + /* > > > + * Higher order nofail allocations are really expensive and > > ~~~~~~~~~~~~ > > Seems we use both higher-order and high-order to describe the > > non 0-order pages in many places. I personally would take high-order, > > higher-order seems to be a little confusing because it's not explicit > > what is compared with and lower. > > > > Surely this is not an issue to this patch, I see a lot of 'higher order' > > in kernel codes. > > > I agree. It sounds like hard to figure out the difference between both. > Are you willing send the patch? If not, i can send it out :) I am fine, please go ahead.
On Thu, Aug 29, 2024 at 04:44:51PM +0800, Baoquan He wrote: > On 08/29/24 at 10:12am, Uladzislau Rezki wrote: > > On Thu, Aug 29, 2024 at 11:48:32AM +0800, Baoquan He wrote: > > > On 08/27/24 at 09:09pm, Uladzislau Rezki (Sony) wrote: > > > > The aim is to simplify and making the vm_area_alloc_pages() > > > > function less confusing as it became more clogged nowadays: > > > > > > > > - eliminate a "bulk_gfp" variable and do not overwrite a gfp > > > > flag for bulk allocator; > > > > - drop __GFP_NOFAIL flag for high-order-page requests on upper > > > > layer. It becomes less spread between levels when it comes to > > > > __GFP_NOFAIL allocations; > > > > - add a comment about a fallback path if high-order attempt is > > > > unsuccessful because for such cases __GFP_NOFAIL is dropped; > > > > - fix a typo in a commit message. > > > > > > > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > > > > --- > > > > mm/vmalloc.c | 37 +++++++++++++++++-------------------- > > > > 1 file changed, 17 insertions(+), 20 deletions(-) > > > > > > > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > > > > index 3f9b6bd707d2..57862865e808 100644 > > > > --- a/mm/vmalloc.c > > > > +++ b/mm/vmalloc.c > > > > @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > > unsigned int order, unsigned int nr_pages, struct page **pages) > > > > { > > > > unsigned int nr_allocated = 0; > > > > - gfp_t alloc_gfp = gfp; > > > > - bool nofail = gfp & __GFP_NOFAIL; > > > > struct page *page; > > > > int i; > > > > > > > > @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > > * more permissive. > > > > */ > > > > if (!order) { > > > > - /* bulk allocator doesn't support nofail req. officially */ > > > > - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; > > > > - > > > > while (nr_allocated < nr_pages) { > > > > unsigned int nr, nr_pages_request; > > > > > > > > @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > > * but mempolicy wants to alloc memory by interleaving. > > > > */ > > > > if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) > > > > - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, > > > > + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, > > > > nr_pages_request, > > > > pages + nr_allocated); > > > > - > > > > else > > > > - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, > > > > + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, > > > > nr_pages_request, > > > > pages + nr_allocated); > > > > > > > > @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, > > > > if (nr != nr_pages_request) > > > > break; > > > > } > > > > - } else if (gfp & __GFP_NOFAIL) { > > > > - /* > > > > - * Higher order nofail allocations are really expensive and > > > > - * potentially dangerous (pre-mature OOM, disruptive reclaim > > > > - * and compaction etc. > > > > - */ > > > > - alloc_gfp &= ~__GFP_NOFAIL; > > > > } > > > > > > > > /* High-order pages or fallback path if "bulk" fails. */ > > > > while (nr_allocated < nr_pages) { > > > > - if (!nofail && fatal_signal_pending(current)) > > > > + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) > > > > break; > > > > > > > > if (nid == NUMA_NO_NODE) > > > > - page = alloc_pages_noprof(alloc_gfp, order); > > > > + page = alloc_pages_noprof(gfp, order); > > > > else > > > > - page = alloc_pages_node_noprof(nid, alloc_gfp, order); > > > > + page = alloc_pages_node_noprof(nid, gfp, order); > > > > + > > > > if (unlikely(!page)) > > > > break; > > > > > > > > /* > > > > * Higher order allocations must be able to be treated as > > > > - * indepdenent small pages by callers (as they can with > > > > + * independent small pages by callers (as they can with > > > > * small-page vmallocs). Some drivers do their own refcounting > > > > * on vmalloc_to_page() pages, some use page->mapping, > > > > * page->lru, etc. > > > > @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, > > > > set_vm_area_page_order(area, page_shift - PAGE_SHIFT); > > > > page_order = vm_area_page_order(area); > > > > > > > > - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, > > > > + /* > > > > + * Higher order nofail allocations are really expensive and > > > ~~~~~~~~~~~~ > > > Seems we use both higher-order and high-order to describe the > > > non 0-order pages in many places. I personally would take high-order, > > > higher-order seems to be a little confusing because it's not explicit > > > what is compared with and lower. > > > > > > Surely this is not an issue to this patch, I see a lot of 'higher order' > > > in kernel codes. > > > > > I agree. It sounds like hard to figure out the difference between both. > > Are you willing send the patch? If not, i can send it out :) > > I am fine, please go ahead. > Good! I will fix it. -- Uladzislau Rezki
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 3f9b6bd707d2..57862865e808 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3531,8 +3531,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, unsigned int order, unsigned int nr_pages, struct page **pages) { unsigned int nr_allocated = 0; - gfp_t alloc_gfp = gfp; - bool nofail = gfp & __GFP_NOFAIL; struct page *page; int i; @@ -3543,9 +3541,6 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * more permissive. */ if (!order) { - /* bulk allocator doesn't support nofail req. officially */ - gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; - while (nr_allocated < nr_pages) { unsigned int nr, nr_pages_request; @@ -3563,12 +3558,11 @@ vm_area_alloc_pages(gfp_t gfp, int nid, * but mempolicy wants to alloc memory by interleaving. */ if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) - nr = alloc_pages_bulk_array_mempolicy_noprof(bulk_gfp, + nr = alloc_pages_bulk_array_mempolicy_noprof(gfp, nr_pages_request, pages + nr_allocated); - else - nr = alloc_pages_bulk_array_node_noprof(bulk_gfp, nid, + nr = alloc_pages_bulk_array_node_noprof(gfp, nid, nr_pages_request, pages + nr_allocated); @@ -3582,30 +3576,24 @@ vm_area_alloc_pages(gfp_t gfp, int nid, if (nr != nr_pages_request) break; } - } else if (gfp & __GFP_NOFAIL) { - /* - * Higher order nofail allocations are really expensive and - * potentially dangerous (pre-mature OOM, disruptive reclaim - * and compaction etc. - */ - alloc_gfp &= ~__GFP_NOFAIL; } /* High-order pages or fallback path if "bulk" fails. */ while (nr_allocated < nr_pages) { - if (!nofail && fatal_signal_pending(current)) + if (!(gfp & __GFP_NOFAIL) && fatal_signal_pending(current)) break; if (nid == NUMA_NO_NODE) - page = alloc_pages_noprof(alloc_gfp, order); + page = alloc_pages_noprof(gfp, order); else - page = alloc_pages_node_noprof(nid, alloc_gfp, order); + page = alloc_pages_node_noprof(nid, gfp, order); + if (unlikely(!page)) break; /* * Higher order allocations must be able to be treated as - * indepdenent small pages by callers (as they can with + * independent small pages by callers (as they can with * small-page vmallocs). Some drivers do their own refcounting * on vmalloc_to_page() pages, some use page->mapping, * page->lru, etc. @@ -3666,7 +3654,16 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, set_vm_area_page_order(area, page_shift - PAGE_SHIFT); page_order = vm_area_page_order(area); - area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, + /* + * Higher order nofail allocations are really expensive and + * potentially dangerous (pre-mature OOM, disruptive reclaim + * and compaction etc. + * + * Please note, the __vmalloc_node_range_noprof() falls-back + * to order-0 pages if high-order attempt is unsuccessful. + */ + area->nr_pages = vm_area_alloc_pages((page_order ? + gfp_mask & ~__GFP_NOFAIL : gfp_mask) | __GFP_NOWARN, node, page_order, nr_small_pages, area->pages); atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
The aim is to simplify and making the vm_area_alloc_pages() function less confusing as it became more clogged nowadays: - eliminate a "bulk_gfp" variable and do not overwrite a gfp flag for bulk allocator; - drop __GFP_NOFAIL flag for high-order-page requests on upper layer. It becomes less spread between levels when it comes to __GFP_NOFAIL allocations; - add a comment about a fallback path if high-order attempt is unsuccessful because for such cases __GFP_NOFAIL is dropped; - fix a typo in a commit message. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> --- mm/vmalloc.c | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-)