search for: xb_set

...t;>> + int ret; >>> + >>> + *pfn_min = min(pfn, *pfn_min); >>> + *pfn_max = max(pfn, *pfn_max); >>> + >>> + do { >>> + if (xb_preload(GFP_NOWAIT | __GFP_NOWARN) < 0) >>> + return -ENOMEM; >>> + >>> + ret = xb_set_bit(&vb->page_xb, pfn); >>> + xb_preload_end(); >>> + } while (unlikely(ret == -EAGAIN)); >> OK, so you don't need a spinlock because you're under a mutex? But you >> can't allocate memory because you're in the balloon driver, and so a >>...

...rote: > From: Matthew Wilcox <mawilcox at microsoft.com> > > The eXtensible Bitmap is a sparse bitmap representation which is > efficient for set bits which tend to cluster. It supports up to > 'unsigned long' worth of bits, and this commit adds the bare bones -- > xb_set_bit(), xb_clear_bit() and xb_test_bit(). > > Signed-off-by: Matthew Wilcox <mawilcox at microsoft.com> > Signed-off-by: Wei Wang <wei.w.wang at intel.com> > Cc: Andrew Morton <akpm at linux-foundation.org> > Cc: Michal Hocko <mhocko at kernel.org> > Cc: Mi...

...rote: > From: Matthew Wilcox <mawilcox at microsoft.com> > > The eXtensible Bitmap is a sparse bitmap representation which is > efficient for set bits which tend to cluster. It supports up to > 'unsigned long' worth of bits, and this commit adds the bare bones -- > xb_set_bit(), xb_clear_bit() and xb_test_bit(). > > Signed-off-by: Matthew Wilcox <mawilcox at microsoft.com> > Signed-off-by: Wei Wang <wei.w.wang at intel.com> > Cc: Andrew Morton <akpm at linux-foundation.org> > Cc: Michal Hocko <mhocko at kernel.org> > Cc: Mi...

On Tue, Dec 12, 2017 at 07:55:55PM +0800, Wei Wang wrote: > +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp); I'm struggling to understand when one would use this. The xb_ API requires you to handle your own locking. But specifying GFP flags here implies you can sleep. So ... um ... there's no locking? > +void xb_clear_bit_range(struct xb *xb, unsigned

On Tue, Dec 12, 2017 at 07:55:55PM +0800, Wei Wang wrote: > +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp); I'm struggling to understand when one would use this. The xb_ API requires you to handle your own locking. But specifying GFP flags here implies you can sleep. So ... um ... there's no locking? > +void xb_clear_bit_range(struct xb *xb, unsigned

...n one would use this. The xb_ API >>> requires you to handle your own locking. But specifying GFP flags >>> here implies you can sleep. So ... um ... there's no locking? >> In the regular use cases, people would do xb_preload() before taking the >> lock, and the xb_set/clear within the lock. >> >> In the virtio-balloon usage, we have a large number of bits to set with >> the balloon_lock being held (we're not unlocking for each bit), so we >> used the above wrapper to do preload and set within the balloon_lock, >> and passed in G...

...mplement it in a style close to find_next_bit; - rename xb_find_next_zero_bit to xb_find_clear, and re-implement it in a stytle close to find_next_zero_bit; - separate the implementation of xb_find_set and xb_find_clear for the convenience of future updates. 3) patch 4: virtio-balloon - xb_set_page: change the way to call xb_ related APIs v18->v19: 1) patch 3: - xb_clear_bit_range and xb_find_next_bit will deal with range [start, end), where end is changed to be exclusive of the range. - add overflow checks at the end of xb_clear_bit_range and xb_find_next_bit - add overflo...

...mplement it in a style close to find_next_bit; - rename xb_find_next_zero_bit to xb_find_clear, and re-implement it in a stytle close to find_next_zero_bit; - separate the implementation of xb_find_set and xb_find_clear for the convenience of future updates. 3) patch 4: virtio-balloon - xb_set_page: change the way to call xb_ related APIs v18->v19: 1) patch 3: - xb_clear_bit_range and xb_find_next_bit will deal with range [start, end), where end is changed to be exclusive of the range. - add overflow checks at the end of xb_clear_bit_range and xb_find_next_bit - add overflo...