freebsd-nq/config/kernel-kmem.m4
Michael Niewöhner 66955885e2 Make use of kvmalloc if available and fix vmem_alloc implementation
This patch implements use of kvmalloc for GFP_KERNEL allocations, which
may increase performance if the allocator is able to allocate physical
memory, if kvmalloc is available as a public kernel interface (since
v4.12). Otherwise it will simply fall back to virtual memory (vmalloc).

Also fix vmem_alloc implementation which can lead to slow allocations
since the first attempt with kmalloc does not make use of the noretry
flag but tells the linux kernel to retry several times before it fails.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Signed-off-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Signed-off-by: Michael Niewöhner <foss@mniewoehner.de>
Closes #9034
2019-11-13 10:05:10 -08:00

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dnl #
dnl # Enabled by default it provides a minimal level of memory tracking.
dnl # A total count of bytes allocated is kept for each alloc and free.
dnl # Then at module unload time a report to the console will be printed
dnl # if memory was leaked.
dnl #
AC_DEFUN([SPL_AC_DEBUG_KMEM], [
AC_ARG_ENABLE([debug-kmem],
[AS_HELP_STRING([--enable-debug-kmem],
[Enable basic kmem accounting @<:@default=no@:>@])],
[],
[enable_debug_kmem=no])
AS_IF([test "x$enable_debug_kmem" = xyes],
[
KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_KMEM"
DEBUG_KMEM="_with_debug_kmem"
AC_DEFINE([DEBUG_KMEM], [1],
[Define to 1 to enable basic kmem accounting])
], [
DEBUG_KMEM="_without_debug_kmem"
])
AC_SUBST(DEBUG_KMEM)
AC_MSG_CHECKING([whether basic kmem accounting is enabled])
AC_MSG_RESULT([$enable_debug_kmem])
])
dnl #
dnl # Disabled by default it provides detailed memory tracking. This
dnl # feature also requires --enable-debug-kmem to be set. When enabled
dnl # not only will total bytes be tracked but also the location of every
dnl # alloc and free. When the SPL module is unloaded a list of all leaked
dnl # addresses and where they were allocated will be dumped to the console.
dnl # Enabling this feature has a significant impact on performance but it
dnl # makes finding memory leaks pretty straight forward.
dnl #
AC_DEFUN([SPL_AC_DEBUG_KMEM_TRACKING], [
AC_ARG_ENABLE([debug-kmem-tracking],
[AS_HELP_STRING([--enable-debug-kmem-tracking],
[Enable detailed kmem tracking @<:@default=no@:>@])],
[],
[enable_debug_kmem_tracking=no])
AS_IF([test "x$enable_debug_kmem_tracking" = xyes],
[
KERNELCPPFLAGS="${KERNELCPPFLAGS} -DDEBUG_KMEM_TRACKING"
DEBUG_KMEM_TRACKING="_with_debug_kmem_tracking"
AC_DEFINE([DEBUG_KMEM_TRACKING], [1],
[Define to 1 to enable detailed kmem tracking])
], [
DEBUG_KMEM_TRACKING="_without_debug_kmem_tracking"
])
AC_SUBST(DEBUG_KMEM_TRACKING)
AC_MSG_CHECKING([whether detailed kmem tracking is enabled])
AC_MSG_RESULT([$enable_debug_kmem_tracking])
])
dnl #
dnl # 4.12 API,
dnl # Added kvmalloc allocation strategy
dnl #
AC_DEFUN([ZFS_AC_KERNEL_SRC_KVMALLOC], [
ZFS_LINUX_TEST_SRC([kvmalloc], [
#include <linux/mm.h>
],[
void *p __attribute__ ((unused));
p = kvmalloc(0, GFP_KERNEL);
])
])
AC_DEFUN([ZFS_AC_KERNEL_KVMALLOC], [
AC_MSG_CHECKING([whether kvmalloc(ptr, flags) is available])
ZFS_LINUX_TEST_RESULT([kvmalloc], [
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_KVMALLOC, 1, [kvmalloc exists])
],[
AC_MSG_RESULT(no)
])
])