41 lines
1.4 KiB
Diff
41 lines
1.4 KiB
Diff
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xentrace: correct formula to calculate t_info_pages
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(xen-unstable changeset 23128:4a335f1000ea)
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The current formula to calculate t_info_pages, based on the initial
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code, is slightly incorrect. It may allocate more than needed.
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Each cpu has some pages/mfns stored as uint32_t.
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That list is stored with an offset at tinfo.
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Signed-off-by: Olaf Hering <olaf@aepfle.de>
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---
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xen/common/trace.c | 7 +++----
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1 file changed, 3 insertions(+), 4 deletions(-)
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Index: xen-4.1.1-testing/xen/common/trace.c
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===================================================================
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--- xen-4.1.1-testing.orig/xen/common/trace.c
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+++ xen-4.1.1-testing/xen/common/trace.c
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@@ -111,7 +111,7 @@ static int calculate_tbuf_size(unsigned
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{
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struct t_buf dummy;
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typeof(dummy.prod) size;
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- unsigned int t_info_words, t_info_bytes;
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+ unsigned int t_info_words;
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/* force maximum value for an unsigned type */
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size = -1;
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@@ -126,9 +126,8 @@ static int calculate_tbuf_size(unsigned
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pages = size;
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}
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- t_info_words = num_online_cpus() * pages + t_info_first_offset;
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- t_info_bytes = t_info_words * sizeof(uint32_t);
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- t_info_pages = PFN_UP(t_info_bytes);
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+ t_info_words = num_online_cpus() * pages * sizeof(uint32_t);
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+ t_info_pages = PFN_UP(t_info_first_offset + t_info_words);
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printk(XENLOG_INFO "xentrace: requesting %u t_info pages "
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"for %u trace pages on %u cpus\n",
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t_info_pages, pages, num_online_cpus());
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