| Message ID | 20170106141107.23953-5-mhocko@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On 01/06/2017 03:11 PM, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} > API to prevent from reclaim recursion into the fs because vmalloc can > invoke unconditional GFP_KERNEL allocations and these functions might be > called from the NOFS contexts. The memalloc_noio_save will enforce > GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be > unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should > provide exactly what we need here - implicit GFP_NOFS context. > > Changes since v1 > - s@memalloc_noio_restore@memalloc_nofs_restore@ in _xfs_buf_map_pages > as per Brian Foster > > Signed-off-by: Michal Hocko <mhocko@suse.com> Not a xfs expert, but seems correct. Acked-by: Vlastimil Babka <vbabka@suse.cz> Nit below: > --- > fs/xfs/kmem.c | 10 +++++----- > fs/xfs/xfs_buf.c | 8 ++++---- > 2 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c > index a76a05dae96b..d69ed5e76621 100644 > --- a/fs/xfs/kmem.c > +++ b/fs/xfs/kmem.c > @@ -65,7 +65,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) > void * > kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > { > - unsigned noio_flag = 0; > + unsigned nofs_flag = 0; > void *ptr; > gfp_t lflags; > > @@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering > * the filesystem here and potentially deadlocking. The comment above is now largely obsolete, or minimally should be changed to PF_MEMALLOC_NOFS? > */ > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - noio_flag = memalloc_noio_save(); > + if (flags & KM_NOFS) > + nofs_flag = memalloc_nofs_save(); > > lflags = kmem_flags_convert(flags); > ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); > > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - memalloc_noio_restore(noio_flag); > + if (flags & KM_NOFS) > + memalloc_nofs_restore(nofs_flag); > > return ptr; > } > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index 7f0a01f7b592..8cb8dd4cdfd8 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -441,17 +441,17 @@ _xfs_buf_map_pages( > bp->b_addr = NULL; > } else { > int retried = 0; > - unsigned noio_flag; > + unsigned nofs_flag; > > /* > * vm_map_ram() will allocate auxillary structures (e.g. > * pagetables) with GFP_KERNEL, yet we are likely to be under > * GFP_NOFS context here. Hence we need to tell memory reclaim > - * that we are in such a context via PF_MEMALLOC_NOIO to prevent > + * that we are in such a context via PF_MEMALLOC_NOFS to prevent > * memory reclaim re-entering the filesystem here and > * potentially deadlocking. > */ > - noio_flag = memalloc_noio_save(); > + nofs_flag = memalloc_nofs_save(); > do { > bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, > -1, PAGE_KERNEL); > @@ -459,7 +459,7 @@ _xfs_buf_map_pages( > break; > vm_unmap_aliases(); > } while (retried++ <= 1); > - memalloc_noio_restore(noio_flag); > + memalloc_nofs_restore(nofs_flag); > > if (!bp->b_addr) > return -ENOMEM; > -- 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
On Fri, Jan 06, 2017 at 03:11:03PM +0100, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} > API to prevent from reclaim recursion into the fs because vmalloc can > invoke unconditional GFP_KERNEL allocations and these functions might be > called from the NOFS contexts. The memalloc_noio_save will enforce > GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be > unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should > provide exactly what we need here - implicit GFP_NOFS context. > > Changes since v1 > - s@memalloc_noio_restore@memalloc_nofs_restore@ in _xfs_buf_map_pages > as per Brian Foster > > Signed-off-by: Michal Hocko <mhocko@suse.com> > --- Looks fine to me: Reviewed-by: Brian Foster <bfoster@redhat.com> > fs/xfs/kmem.c | 10 +++++----- > fs/xfs/xfs_buf.c | 8 ++++---- > 2 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c > index a76a05dae96b..d69ed5e76621 100644 > --- a/fs/xfs/kmem.c > +++ b/fs/xfs/kmem.c > @@ -65,7 +65,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) > void * > kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > { > - unsigned noio_flag = 0; > + unsigned nofs_flag = 0; > void *ptr; > gfp_t lflags; > > @@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering > * the filesystem here and potentially deadlocking. > */ > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - noio_flag = memalloc_noio_save(); > + if (flags & KM_NOFS) > + nofs_flag = memalloc_nofs_save(); > > lflags = kmem_flags_convert(flags); > ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); > > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - memalloc_noio_restore(noio_flag); > + if (flags & KM_NOFS) > + memalloc_nofs_restore(nofs_flag); > > return ptr; > } > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index 7f0a01f7b592..8cb8dd4cdfd8 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -441,17 +441,17 @@ _xfs_buf_map_pages( > bp->b_addr = NULL; > } else { > int retried = 0; > - unsigned noio_flag; > + unsigned nofs_flag; > > /* > * vm_map_ram() will allocate auxillary structures (e.g. > * pagetables) with GFP_KERNEL, yet we are likely to be under > * GFP_NOFS context here. Hence we need to tell memory reclaim > - * that we are in such a context via PF_MEMALLOC_NOIO to prevent > + * that we are in such a context via PF_MEMALLOC_NOFS to prevent > * memory reclaim re-entering the filesystem here and > * potentially deadlocking. > */ > - noio_flag = memalloc_noio_save(); > + nofs_flag = memalloc_nofs_save(); > do { > bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, > -1, PAGE_KERNEL); > @@ -459,7 +459,7 @@ _xfs_buf_map_pages( > break; > vm_unmap_aliases(); > } while (retried++ <= 1); > - memalloc_noio_restore(noio_flag); > + memalloc_nofs_restore(nofs_flag); > > if (!bp->b_addr) > return -ENOMEM; > -- > 2.11.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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
On Fri, Jan 06, 2017 at 03:11:03PM +0100, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > kmem_zalloc_large and _xfs_buf_map_pages use memalloc_noio_{save,restore} > API to prevent from reclaim recursion into the fs because vmalloc can > invoke unconditional GFP_KERNEL allocations and these functions might be > called from the NOFS contexts. The memalloc_noio_save will enforce > GFP_NOIO context which is even weaker than GFP_NOFS and that seems to be > unnecessary. Let's use memalloc_nofs_{save,restore} instead as it should > provide exactly what we need here - implicit GFP_NOFS context. > > Changes since v1 > - s@memalloc_noio_restore@memalloc_nofs_restore@ in _xfs_buf_map_pages > as per Brian Foster > > Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> > --- > fs/xfs/kmem.c | 10 +++++----- > fs/xfs/xfs_buf.c | 8 ++++---- > 2 files changed, 9 insertions(+), 9 deletions(-) > > diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c > index a76a05dae96b..d69ed5e76621 100644 > --- a/fs/xfs/kmem.c > +++ b/fs/xfs/kmem.c > @@ -65,7 +65,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) > void * > kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > { > - unsigned noio_flag = 0; > + unsigned nofs_flag = 0; > void *ptr; > gfp_t lflags; > > @@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) > * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering > * the filesystem here and potentially deadlocking. > */ > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - noio_flag = memalloc_noio_save(); > + if (flags & KM_NOFS) > + nofs_flag = memalloc_nofs_save(); > > lflags = kmem_flags_convert(flags); > ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); > > - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) > - memalloc_noio_restore(noio_flag); > + if (flags & KM_NOFS) > + memalloc_nofs_restore(nofs_flag); > > return ptr; > } > diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c > index 7f0a01f7b592..8cb8dd4cdfd8 100644 > --- a/fs/xfs/xfs_buf.c > +++ b/fs/xfs/xfs_buf.c > @@ -441,17 +441,17 @@ _xfs_buf_map_pages( > bp->b_addr = NULL; > } else { > int retried = 0; > - unsigned noio_flag; > + unsigned nofs_flag; > > /* > * vm_map_ram() will allocate auxillary structures (e.g. > * pagetables) with GFP_KERNEL, yet we are likely to be under > * GFP_NOFS context here. Hence we need to tell memory reclaim > - * that we are in such a context via PF_MEMALLOC_NOIO to prevent > + * that we are in such a context via PF_MEMALLOC_NOFS to prevent > * memory reclaim re-entering the filesystem here and > * potentially deadlocking. > */ > - noio_flag = memalloc_noio_save(); > + nofs_flag = memalloc_nofs_save(); > do { > bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, > -1, PAGE_KERNEL); > @@ -459,7 +459,7 @@ _xfs_buf_map_pages( > break; > vm_unmap_aliases(); > } while (retried++ <= 1); > - memalloc_noio_restore(noio_flag); > + memalloc_nofs_restore(nofs_flag); > > if (!bp->b_addr) > return -ENOMEM; > -- > 2.11.0 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- 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
diff --git a/fs/xfs/kmem.c b/fs/xfs/kmem.c index a76a05dae96b..d69ed5e76621 100644 --- a/fs/xfs/kmem.c +++ b/fs/xfs/kmem.c @@ -65,7 +65,7 @@ kmem_alloc(size_t size, xfs_km_flags_t flags) void * kmem_zalloc_large(size_t size, xfs_km_flags_t flags) { - unsigned noio_flag = 0; + unsigned nofs_flag = 0; void *ptr; gfp_t lflags; @@ -80,14 +80,14 @@ kmem_zalloc_large(size_t size, xfs_km_flags_t flags) * context via PF_MEMALLOC_NOIO to prevent memory reclaim re-entering * the filesystem here and potentially deadlocking. */ - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - noio_flag = memalloc_noio_save(); + if (flags & KM_NOFS) + nofs_flag = memalloc_nofs_save(); lflags = kmem_flags_convert(flags); ptr = __vmalloc(size, lflags | __GFP_HIGHMEM | __GFP_ZERO, PAGE_KERNEL); - if ((current->flags & PF_MEMALLOC_NOFS) || (flags & KM_NOFS)) - memalloc_noio_restore(noio_flag); + if (flags & KM_NOFS) + memalloc_nofs_restore(nofs_flag); return ptr; } diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index 7f0a01f7b592..8cb8dd4cdfd8 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -441,17 +441,17 @@ _xfs_buf_map_pages( bp->b_addr = NULL; } else { int retried = 0; - unsigned noio_flag; + unsigned nofs_flag; /* * vm_map_ram() will allocate auxillary structures (e.g. * pagetables) with GFP_KERNEL, yet we are likely to be under * GFP_NOFS context here. Hence we need to tell memory reclaim - * that we are in such a context via PF_MEMALLOC_NOIO to prevent + * that we are in such a context via PF_MEMALLOC_NOFS to prevent * memory reclaim re-entering the filesystem here and * potentially deadlocking. */ - noio_flag = memalloc_noio_save(); + nofs_flag = memalloc_nofs_save(); do { bp->b_addr = vm_map_ram(bp->b_pages, bp->b_page_count, -1, PAGE_KERNEL); @@ -459,7 +459,7 @@ _xfs_buf_map_pages( break; vm_unmap_aliases(); } while (retried++ <= 1); - memalloc_noio_restore(noio_flag); + memalloc_nofs_restore(nofs_flag); if (!bp->b_addr) return -ENOMEM;