Messages in this thread Patch in this message | | | From | "Yang, Bo" <> | Date | Mon, 4 Aug 2008 06:40:27 -0600 | Subject | RE: [PATCH 9/10] drivers/scsi/megaraid: Use DIV_ROUND_UP |
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Julia,
Frame_count is the major parameter used by our megaraid sas FW. It may cause some issues after this change. Please keep the original implementation.
Thanks.
Bo Yang
-----Original Message----- From: Julia Lawall [mailto:julia@diku.dk] Sent: Saturday, August 02, 2008 11:16 AM To: DL-MegaRAID Linux; linux-scsi@vger.kernel.org; linux-kernel@vger.kernel.org; kernel-janitors@vger.kernel.org Subject: [PATCH 9/10] drivers/scsi/megaraid: Use DIV_ROUND_UP
From: Julia Lawall <julia@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; @@
( - (n + d - 1) / d + DIV_ROUND_UP(n,d) | - (n + (d - 1)) / d + DIV_ROUND_UP(n,d) )
@depends on haskernel@ expression n,d; @@
- DIV_ROUND_UP((n),d) + DIV_ROUND_UP(n,d)
@depends on haskernel@ expression n,d; @@
- DIV_ROUND_UP(n,(d)) + DIV_ROUND_UP(n,d) // </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
--- drivers/scsi/megaraid/megaraid_sas.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff -u -p a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c --- a/drivers/scsi/megaraid/megaraid_sas.c +++ b/drivers/scsi/megaraid/megaraid_sas.c @@ -1615,7 +1615,7 @@ static int megasas_create_frame_pool(str * Calculated the number of 64byte frames required for SGL */ sgl_sz = sge_sz * instance->max_num_sge; - frame_count = (sgl_sz + MEGAMFI_FRAME_SIZE - 1) / MEGAMFI_FRAME_SIZE; + frame_count = DIV_ROUND_UP(sgl_sz, MEGAMFI_FRAME_SIZE);
/* * We need one extra frame for the MFI command
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