search for: div_round_up

From: Julia Lawall <julia at diku.dk> The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) / (d)) but is perhaps more readable. An extract of the semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @haskernel@ @@ #include <linux/kernel.h> @depends on haskernel@ expression n,d; @@...

...drivers/misc/vmw_vmci/vmci_queue_pair.c index 35f19a6..6d5144c 100644 --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -295,12 +295,20 @@ static void *qp_alloc_queue(u64 size, u32 flags) { u64 i; struct vmci_queue *queue; - const size_t num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1; - const size_t pas_size = num_pages * sizeof(*queue->kernel_if->u.g.pas); - const size_t vas_size = num_pages * sizeof(*queue->kernel_if->u.g.vas); - const size_t queue_size = - sizeof(*queue) + sizeof(*queue->kernel_if) + - pas_size + vas_size; + size_t pas_s...

...drivers/misc/vmw_vmci/vmci_queue_pair.c index 35f19a6..6d5144c 100644 --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -295,12 +295,20 @@ static void *qp_alloc_queue(u64 size, u32 flags) { u64 i; struct vmci_queue *queue; - const size_t num_pages = DIV_ROUND_UP(size, PAGE_SIZE) + 1; - const size_t pas_size = num_pages * sizeof(*queue->kernel_if->u.g.pas); - const size_t vas_size = num_pages * sizeof(*queue->kernel_if->u.g.vas); - const size_t queue_size = - sizeof(*queue) + sizeof(*queue->kernel_if) + - pas_size + vas_size; + size_t pas_s...

...1; static uint8_t *bitmap; /* Size of the bitmap in bytes. */ -static uint64_t bm_size; +static size_t bm_size; enum bm_entry { BLOCK_NOT_CACHED = 0, @@ -167,7 +167,14 @@ blk_set_size (uint64_t new_size) { uint8_t *new_bm; const size_t old_bm_size = bm_size; - size_t new_bm_size = DIV_ROUND_UP (new_size, BLKSIZE*8/2); + uint64_t new_bm_size_u64 = DIV_ROUND_UP (new_size, BLKSIZE*8/2); + size_t new_bm_size; + + if (new_bm_size_u64 > SIZE_MAX) { + nbdkit_error ("bitmap too large for this architecture"); + return -1; + } + new_bm_size = (size_t) new_bm_size_u64;...

On Thu, Mar 09, 2023 at 11:21:23PM +0800, Yangtao Li wrote: > Use i_blockmask() to simplify code. Umm... What's the branchpoint for that series? Not the mainline - there we have i_blocksize() open-coded... > Signed-off-by: Yangtao Li <frank.li at vivo.com> > --- > v3: > -none > v2: > -convert to i_blockmask() > fs/erofs/data.c | 2 +- > 1 file changed, 1

When counting required slots for skb, netback directly uses DIV_ROUND_UP to get slots required by header data. This is wrong when offset in the page of header data is not zero, and is also inconsistent with following calculation for required slot in netbk_gop_skb. In netbk_gop_skb, required slots are calculated based on offset and len in page of header data. It is poss...

Since we're using ({ .. }) gcc/clang extension, let's rewrite the rounding.h change too. Rich.

...next multiple of n (n must be a power of 2). + */ +#define ROUND_DOWN(i, n) ({ \ + assert (is_power_of_2 (n)); \ + (i) & ~((n) - 1); \ +}) + +/* Return n / d, rounding the result up to the next integer. */ +#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) + +#endif /* NBDKIT_ROUNDING_H */ diff --git a/filters/cache/Makefile.am b/filters/cache/Makefile.am index 867812e..827ff17 100644 --- a/filters/cache/Makefile.am +++ b/filters/cache/Makefile.am @@ -41,7 +41,8 @@ nbdkit_cache_filter_la_SOURCES = \ $(top_srcdir)/inclu...

...*pas; + void **vas; + } g; /* Used by the guest. */ + struct { + struct page **page; + struct page **header_page; + } h; /* Used by the host. */ + } u; }; /* @@ -263,59 +272,65 @@ static void qp_free_queue(void *q, u64 size) struct vmci_queue *queue = q; if (queue) { - u64 i = DIV_ROUND_UP(size, PAGE_SIZE); + u64 i; - while (i) - __free_page(queue->kernel_if->page[--i]); + /* Given size does not include header, so add in a page here. */ + for (i = 0; i < DIV_ROUND_UP(size, PAGE_SIZE) + 1; i++) { + dma_free_coherent(&vmci_pdev->dev, PAGE_SIZE, + queue-&...

Hi, I ran into an issue where netback driver is crashing with BUG_ON(npo.meta_prod > ARRAY_SIZE(netbk->meta)). It is happening in Intel 10Gbps network when larger mtu values are used. The problem seems to be the way the slots are counted. After applying this patch things ran fine in my environment. I request to validate my changes. Thanks Siva

...s, > Ilya Thanks a lot for the pointer. I think this was in response to this: https://patchwork.ozlabs.org/patch/558324/ > > > > + skb_push(skb, skb->data - skb_data_orig); > > sq->skb[pi] = skb; > > > > MLX5E_TX_SKB_CB(skb)->num_wqebbs = DIV_ROUND_UP(ds_cnt, > > And in the middle of this we have: > > skb_pull_inline(skb, ihs); > > This is looks illegal. > > You must not modify the data pointers of any SKB that you receive for > sending via ->ndo_start_xmit() unless you know that absolutely you a...

...s, > Ilya Thanks a lot for the pointer. I think this was in response to this: https://patchwork.ozlabs.org/patch/558324/ > > > > + skb_push(skb, skb->data - skb_data_orig); > > sq->skb[pi] = skb; > > > > MLX5E_TX_SKB_CB(skb)->num_wqebbs = DIV_ROUND_UP(ds_cnt, > > And in the middle of this we have: > > skb_pull_inline(skb, ihs); > > This is looks illegal. > > You must not modify the data pointers of any SKB that you receive for > sending via ->ndo_start_xmit() unless you know that absolutely you a...

...is variable size in multiple of 4 bytes, and its size is defined > in the header block Baseline_ELD_Len field (in number of > DWords). > > Do not include the header size in Baseline_ELD_Len field. Fix all known > users of eld[2]. > > While at it, switch to DIV_ROUND_UP instead of open coding it. > > Signed-off-by: Jani Nikula <jani.nikula at intel.com> > > --- > > This is based on an audio rework series which is mid-way being merged to > i915. I don't think this should be cc: stable worthy, as, AFAICT, we > don't use the vend...

When counting required slots for skb, netback directly uses DIV_ROUND_UP to get slots required by header data. This is wrong when offset in the page of header data is not zero, and is also inconsistent with following calculation for required slot in netbk_gop_skb. In netbk_gop_skb, required slots are calculated based on offset and len in page of header data. It is poss...

...a_data *mpd, > { > struct inode *inode = mpd->inode; > int err; > - ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1) > + ext4_lblk_t blocks = (i_size_read(inode) + i_blockmask(inode)) > >> inode->i_blkbits; Umm... That actually asks for DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inode)) - compiler should bloody well be able to figure out that division by (1 << n) is shift down by n and it's easier to follow that way...

...have i_blocksize() open-coded... > > Sorry, I'm based on the latest branch of the erofs repository. > > https://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git/log/?h=dev-test > > I think I can resend based on mainline. > > > Umm... That actually asks for DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inode)) > > - compiler should bloody well be able to figure out that division by (1 << n) > > is shift down by n and it's easier to follow that way... > > So it seems better to change to DIV_ROUND_UP(i_size_read_inode(), i_blocksize(inod...

...dr_len); + rq->min_buf_len, PAGE_SIZE - hdr_len); return ALIGN(len, L1_CACHE_BYTES); } @@ -2039,7 +2039,8 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len; unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size); - return max(min_buf_len, hdr_len); + return max(max(min_buf_len, hdr_len) - hdr_len, + (unsigned int)GOOD_PACKET_LEN); } static int virtnet_find_vqs(struct virtnet_info *vi) -- MST

...dr_len); + rq->min_buf_len, PAGE_SIZE - hdr_len); return ALIGN(len, L1_CACHE_BYTES); } @@ -2039,7 +2039,8 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu unsigned int buf_len = hdr_len + ETH_HLEN + VLAN_HLEN + packet_len; unsigned int min_buf_len = DIV_ROUND_UP(buf_len, rq_size); - return max(min_buf_len, hdr_len); + return max(max(min_buf_len, hdr_len) - hdr_len, + (unsigned int)GOOD_PACKET_LEN); } static int virtnet_find_vqs(struct virtnet_info *vi) -- MST

...next multiple of n (n must be a power of 2). + */ +#define ROUND_DOWN(i, n) ({ \ + assert (is_power_of_2 (n)); \ + (i) & -((typeof (i))(n)); \ +}) + +/* Return n / d, rounding the result up to the next integer. */ +#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d)) + +#endif /* NBDKIT_ROUNDING_H */ diff --git a/filters/cache/Makefile.am b/filters/cache/Makefile.am index 867812e..827ff17 100644 --- a/filters/cache/Makefile.am +++ b/filters/cache/Makefile.am @@ -41,7 +41,8 @@ nbdkit_cache_filter_la_SOURCES = \ $(top_srcdir)/inclu...

This series does some refactoring in the GK20A's volt and clk drivers (fixing a few things while we are at it) to let GM20B benefit from the GK20A's logic with which it is compatible. GM20B is capable of more sophisticated (and power-efficient) reclocking which will follow later. Even after this more fancy reclocking is merged, the present logic will remain used in the lowest speedo of