Revision c0cf4512a31eb3cec70b066bc36ed55f7d05b8c0 authored by Bart Van Assche on 23 June 2016, 07:35:48 UTC, committed by Doug Ledford on 23 June 2016, 16:04:09 UTC
The memory needed for the send and receive queues associated with a QP is proportional to the max_sge parameter. The current value of that parameter is such that with an mlx4 HCA the QP buffer size is 8 MB. Since DMA is used for communication between HCA and CPU that buffer either has to be allocated coherently or map_single() must succeed for that buffer. Since large contiguous allocations are fragile and since the maximum segment size for e.g. swiotlb is 256 KB, reduce the max_sge parameter. This patch avoids that the following text appears on the console after SRP logout and relogin on a system equipped with multiple IB HCAs: mlx4_core 0000:05:00.0: swiotlb buffer is full (sz: 8388608 bytes) swiotlb: coherent allocation failed for device 0000:05:00.0 size=8388608 CPU: 11 PID: 148 Comm: kworker/11:1 Not tainted 4.7.0-rc4-dbg+ #1 Call Trace: [<ffffffff812c6d35>] dump_stack+0x67/0x92 [<ffffffff812efe71>] swiotlb_alloc_coherent+0x141/0x150 [<ffffffff810458be>] x86_swiotlb_alloc_coherent+0x3e/0x50 [<ffffffffa03861fa>] mlx4_buf_direct_alloc.isra.5+0x9a/0x120 [mlx4_core] [<ffffffffa0386545>] mlx4_buf_alloc+0x165/0x1a0 [mlx4_core] [<ffffffffa035053d>] create_qp_common.isra.29+0x57d/0xff0 [mlx4_ib] [<ffffffffa03510da>] mlx4_ib_create_qp+0x12a/0x3f0 [mlx4_ib] [<ffffffffa031154a>] ib_create_qp+0x3a/0x250 [ib_core] [<ffffffffa055dd4b>] srpt_cm_handler+0x4bb/0xcad [ib_srpt] [<ffffffffa02c1ab0>] cm_process_work+0x20/0xf0 [ib_cm] [<ffffffffa02c3640>] cm_work_handler+0x1ac0/0x2059 [ib_cm] [<ffffffff810737ed>] process_one_work+0x19d/0x490 [<ffffffff81073b29>] worker_thread+0x49/0x490 [<ffffffff8107a0ea>] kthread+0xea/0x100 [<ffffffff815b25af>] ret_from_fork+0x1f/0x40 Fixes: b99f8e4d7bcd ("IB/srpt: convert to the generic RDMA READ/WRITE API") Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Laurence Oberman <loberman@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Doug Ledford <dledford@redhat.com>
1 parent 37e07cd
div64.c
/*
* Copyright (C) 2003 Bernardo Innocenti <bernie@develer.com>
*
* Based on former do_div() implementation from asm-parisc/div64.h:
* Copyright (C) 1999 Hewlett-Packard Co
* Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com>
*
*
* Generic C version of 64bit/32bit division and modulo, with
* 64bit result and 32bit remainder.
*
* The fast case for (n>>32 == 0) is handled inline by do_div().
*
* Code generated for this function might be very inefficient
* for some CPUs. __div64_32() can be overridden by linking arch-specific
* assembly versions such as arch/ppc/lib/div64.S and arch/sh/lib/div64.S
* or by defining a preprocessor macro in arch/include/asm/div64.h.
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/math64.h>
/* Not needed on 64bit architectures */
#if BITS_PER_LONG == 32
#ifndef __div64_32
uint32_t __attribute__((weak)) __div64_32(uint64_t *n, uint32_t base)
{
uint64_t rem = *n;
uint64_t b = base;
uint64_t res, d = 1;
uint32_t high = rem >> 32;
/* Reduce the thing a bit first */
res = 0;
if (high >= base) {
high /= base;
res = (uint64_t) high << 32;
rem -= (uint64_t) (high*base) << 32;
}
while ((int64_t)b > 0 && b < rem) {
b = b+b;
d = d+d;
}
do {
if (rem >= b) {
rem -= b;
res += d;
}
b >>= 1;
d >>= 1;
} while (d);
*n = res;
return rem;
}
EXPORT_SYMBOL(__div64_32);
#endif
#ifndef div_s64_rem
s64 div_s64_rem(s64 dividend, s32 divisor, s32 *remainder)
{
u64 quotient;
if (dividend < 0) {
quotient = div_u64_rem(-dividend, abs(divisor), (u32 *)remainder);
*remainder = -*remainder;
if (divisor > 0)
quotient = -quotient;
} else {
quotient = div_u64_rem(dividend, abs(divisor), (u32 *)remainder);
if (divisor < 0)
quotient = -quotient;
}
return quotient;
}
EXPORT_SYMBOL(div_s64_rem);
#endif
/**
* div64_u64_rem - unsigned 64bit divide with 64bit divisor and remainder
* @dividend: 64bit dividend
* @divisor: 64bit divisor
* @remainder: 64bit remainder
*
* This implementation is a comparable to algorithm used by div64_u64.
* But this operation, which includes math for calculating the remainder,
* is kept distinct to avoid slowing down the div64_u64 operation on 32bit
* systems.
*/
#ifndef div64_u64_rem
u64 div64_u64_rem(u64 dividend, u64 divisor, u64 *remainder)
{
u32 high = divisor >> 32;
u64 quot;
if (high == 0) {
u32 rem32;
quot = div_u64_rem(dividend, divisor, &rem32);
*remainder = rem32;
} else {
int n = 1 + fls(high);
quot = div_u64(dividend >> n, divisor >> n);
if (quot != 0)
quot--;
*remainder = dividend - quot * divisor;
if (*remainder >= divisor) {
quot++;
*remainder -= divisor;
}
}
return quot;
}
EXPORT_SYMBOL(div64_u64_rem);
#endif
/**
* div64_u64 - unsigned 64bit divide with 64bit divisor
* @dividend: 64bit dividend
* @divisor: 64bit divisor
*
* This implementation is a modified version of the algorithm proposed
* by the book 'Hacker's Delight'. The original source and full proof
* can be found here and is available for use without restriction.
*
* 'http://www.hackersdelight.org/hdcodetxt/divDouble.c.txt'
*/
#ifndef div64_u64
u64 div64_u64(u64 dividend, u64 divisor)
{
u32 high = divisor >> 32;
u64 quot;
if (high == 0) {
quot = div_u64(dividend, divisor);
} else {
int n = 1 + fls(high);
quot = div_u64(dividend >> n, divisor >> n);
if (quot != 0)
quot--;
if ((dividend - quot * divisor) >= divisor)
quot++;
}
return quot;
}
EXPORT_SYMBOL(div64_u64);
#endif
/**
* div64_s64 - signed 64bit divide with 64bit divisor
* @dividend: 64bit dividend
* @divisor: 64bit divisor
*/
#ifndef div64_s64
s64 div64_s64(s64 dividend, s64 divisor)
{
s64 quot, t;
quot = div64_u64(abs(dividend), abs(divisor));
t = (dividend ^ divisor) >> 63;
return (quot ^ t) - t;
}
EXPORT_SYMBOL(div64_s64);
#endif
#endif /* BITS_PER_LONG == 32 */
/*
* Iterative div/mod for use when dividend is not expected to be much
* bigger than divisor.
*/
u32 iter_div_u64_rem(u64 dividend, u32 divisor, u64 *remainder)
{
return __iter_div_u64_rem(dividend, divisor, remainder);
}
EXPORT_SYMBOL(iter_div_u64_rem);
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