563054a863
- Don't try to set max_kernel_pages during ksm init on newer kernels
(#558281)
- Add logfile options for ksmtuned debug.
42 lines
1.4 KiB
Diff
42 lines
1.4 KiB
Diff
If we go over the maximum number of iovecs support by syscall we get
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back EINVAL from the kernel which translate to I/O errors for the guest.
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Add a MAX_IOV defintion for platforms that don't have it. For now we use
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the same 1024 define that's used on Linux and various other platforms,
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but until the windows block backend implements some kind of vectored I/O
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it doesn't matter.
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Signed-off-by: Christoph Hellwig <hch@lst.de>
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Index: qemu/block.c
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===================================================================
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--- qemu.orig/block.c 2010-01-26 10:59:39.757004445 +0100
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+++ qemu/block.c 2010-01-26 11:01:38.056023231 +0100
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@@ -1689,6 +1689,10 @@ static int multiwrite_merge(BlockDriverS
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merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
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}
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+ if (reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1 > IOV_MAX) {
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+ merge = 0;
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+ }
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+
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if (merge) {
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size_t size;
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QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
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Index: qemu/qemu-common.h
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===================================================================
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--- qemu.orig/qemu-common.h 2010-01-26 14:41:40.894254285 +0100
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+++ qemu/qemu-common.h 2010-01-26 14:42:27.267275698 +0100
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@@ -54,6 +54,10 @@ struct iovec {
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void *iov_base;
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size_t iov_len;
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};
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+/*
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+ * Use the same value as Linux for now.
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+ */
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+#define IOV_MAX 1024
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#else
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#include <sys/uio.h>
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#endif
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