search for: xb_find_next_set_bit

...b_set_bit(struct xb *xb, unsigned long bit); +int xb_preload_and_set_bit(struct xb *xb, unsigned long bit, gfp_t gfp); bool xb_test_bit(const struct xb *xb, unsigned long bit); -int xb_clear_bit(struct xb *xb, unsigned long bit); +void xb_clear_bit(struct xb *xb, unsigned long bit); +unsigned long xb_find_next_set_bit(struct xb *xb, unsigned long start, + unsigned long end); +unsigned long xb_find_next_zero_bit(struct xb *xb, unsigned long start, + unsigned long end); +void xb_clear_bit_range(struct xb *xb, unsigned long start, unsigned long end); static inline bool xb_empty(const struct xb *xb)...

...+ 1, IDA_BITMAP_BITS - bit); if (set) ret = find_next_bit(bitmap->bitmap, nbits, bit); else ret = find_next_zero_bit(bitmap->bitmap, nbits, bit); if (ret < nbits) return ret + ida_start; >>>> +/** >>>> + * xb_find_next_set_bit - find the next set bit in a range >>>> + * @xb: the xbitmap to search >>>> + * @start: the start of the range, inclusive >>>> + * @end: the end of the range, exclusive >>>> + * >>>> + * Returns: the index of the found bit, or @end + 1 if...

...exception path after minimum version is merged. > This series is too difficult for me to close corner cases. That exception path is claimed to save memory, and I don't have a strong reason to remove that part. Matthew, could we get your feedback on this? > >> +/** >> + * xb_find_next_set_bit - find the next set bit in a range >> + * @xb: the xbitmap to search >> + * @start: the start of the range, inclusive >> + * @end: the end of the range, exclusive >> + * >> + * Returns: the index of the found bit, or @end + 1 if no such bit is found. >> + */ >...

...IDA_BITMAP_BITS, bit); + else + ret = find_next_zero_bit(bmap->bitmap, + IDA_BITMAP_BITS, bit); + if (ret < IDA_BITMAP_BITS) + return ret + index * IDA_BITMAP_BITS; + } else if (!bmap && !set) { + return start; + } + } + + return ret; +} + +unsigned long xb_find_next_set_bit(struct xb *xb, unsigned long start, + unsigned long end) +{ + return xb_find_next_bit(xb, start, end, 1); +} + +unsigned long xb_find_next_zero_bit(struct xb *xb, unsigned long start, + unsigned long end) +{ + return xb_find_next_bit(xb, start, end, 0); +} + +static void xbitmap_check_...

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

...ox 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(), xb_clear_bit_range(), xb_test_bit(), xb_find_next_set_bit(), xb_find_next_zero_bit(). More possible optimizations to add in the future: 1) xb_set_bit_range: set a range of bits. 2) when searching a bit, if the bit is not found in the slot, move on to the next slot directly. 3) add Tags to help searching. Signed-off-by: Wei Wang <wei.w.wang at intel.c...

On Fri, Dec 15, 2017 at 01:29:45AM +0900, Tetsuo Handa wrote: > > > Also, one more thing you need to check. Have you checked how long does > > > xb_find_next_set_bit(xb, 0, ULONG_MAX) on an empty xbitmap takes? > > > If it causes soft lockup warning, should we add cond_resched() ? > > > If yes, you have to document that this API might sleep. If no, you > > > have to document that the caller of this API is responsible for > > &gt...

...[0, ULONG_MAX)) will take too long time. This can be optimized in > > the future. > > - remove the exceptional path; > > - remove xb_preload_and_set(); > > - reimplement xb_clear_bit_range to make its usage close to > > bitmap_clear; > > - rename xb_find_next_set_bit to xb_find_set, and re-implement 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 &gt...

...[0, ULONG_MAX)) will take too long time. This can be optimized in > > the future. > > - remove the exceptional path; > > - remove xb_preload_and_set(); > > - reimplement xb_clear_bit_range to make its usage close to > > bitmap_clear; > > - rename xb_find_next_set_bit to xb_find_set, and re-implement 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 &gt...

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

This patch series enhances the existing virtio-balloon with the following new features: 1) fast ballooning: transfer ballooned pages between the guest and host in chunks using sgs, instead of one array each time; and 2) free page block reporting: a new virtqueue to report guest free pages to the host. The second feature can be used to accelerate live migration of VMs. Here are some details: Live

...; [0, ULONG_MAX)) will take too long time. This can be optimized in >> the future. >> - remove the exceptional path; >> - remove xb_preload_and_set(); >> - reimplement xb_clear_bit_range to make its usage close to >> bitmap_clear; >> - rename xb_find_next_set_bit to xb_find_set, and re-implement 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 >&gt...

...; [0, ULONG_MAX)) will take too long time. This can be optimized in >> the future. >> - remove the exceptional path; >> - remove xb_preload_and_set(); >> - reimplement xb_clear_bit_range to make its usage close to >> bitmap_clear; >> - rename xb_find_next_set_bit to xb_find_set, and re-implement 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 >&gt...

...d long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long pfn_start, pfn_end; > + uint64_t addr; > + uint32_t len, max_len = round_down(UINT_MAX, PAGE_SIZE); > + > + pfn_start = page_xb_start; > + while (pfn_start < page_xb_end) { > + pfn_start = xb_find_next_set_bit(&vb->page_xb, pfn_start, > + page_xb_end); > + if (pfn_start == page_xb_end + 1) > + break; > + pfn_end = xb_find_next_zero_bit(&vb->page_xb, > + pfn_start + 1, > + page_xb_end); > + addr = pfn_start << PAGE_SHIFT; > + len = (pfn_end...

...d long page_xb_start, > + unsigned long page_xb_end) > +{ > + unsigned long pfn_start, pfn_end; > + uint64_t addr; > + uint32_t len, max_len = round_down(UINT_MAX, PAGE_SIZE); > + > + pfn_start = page_xb_start; > + while (pfn_start < page_xb_end) { > + pfn_start = xb_find_next_set_bit(&vb->page_xb, pfn_start, > + page_xb_end); > + if (pfn_start == page_xb_end + 1) > + break; > + pfn_end = xb_find_next_zero_bit(&vb->page_xb, > + pfn_start + 1, > + page_xb_end); > + addr = pfn_start << PAGE_SHIFT; > + len = (pfn_end...