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ec1fea4516
A previous commit enabled the tracking of object allocations
in Linux-backed caches from the SPL layer for debuggability.
The commit is: 9a170fc6fe
Unfortunately, it also introduced minor performance regressions
that were highlighted by the ZFS perf test-suite. Within Delphix
we found that the regression would be from -1%, all the way up
to -8% for some workloads.
This commit brings performance back up to par by creating a
separate counter for those caches and making it a percpu in
order to avoid lock-contention.
The initial performance testing was done by myself, and the
final round was conducted by @tonynguien who was also the one
that discovered the regression and highlighted the culprit.
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #10397
35 lines
857 B
Plaintext
35 lines
857 B
Plaintext
dnl #
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dnl # 3.18 API change,
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dnl # The function percpu_counter_init now must be passed a GFP mask.
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dnl #
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AC_DEFUN([ZFS_AC_KERNEL_SRC_PERCPU_COUNTER_INIT], [
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ZFS_LINUX_TEST_SRC([percpu_counter_init_with_gfp], [
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#include <linux/gfp.h>
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#include <linux/percpu_counter.h>
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],[
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struct percpu_counter counter;
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int error;
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error = percpu_counter_init(&counter, 0, GFP_KERNEL);
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])
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])
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AC_DEFUN([ZFS_AC_KERNEL_PERCPU_COUNTER_INIT], [
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AC_MSG_CHECKING([whether percpu_counter_init() wants gfp_t])
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ZFS_LINUX_TEST_RESULT([percpu_counter_init_with_gfp], [
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AC_MSG_RESULT(yes)
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AC_DEFINE(HAVE_PERCPU_COUNTER_INIT_WITH_GFP, 1,
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[percpu_counter_init() wants gfp_t])
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],[
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AC_MSG_RESULT(no)
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])
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])
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AC_DEFUN([ZFS_AC_KERNEL_SRC_PERCPU], [
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ZFS_AC_KERNEL_SRC_PERCPU_COUNTER_INIT
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])
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AC_DEFUN([ZFS_AC_KERNEL_PERCPU], [
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ZFS_AC_KERNEL_PERCPU_COUNTER_INIT
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])
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