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124 lines
3.6 KiB
124 lines
3.6 KiB
From 997778e332e9f6d3d1c42e9a222fcab8d4732c40 Mon Sep 17 00:00:00 2001 |
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From: Michal Sekletar <msekleta@redhat.com> |
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Date: Fri, 27 May 2016 14:29:17 +0200 |
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Subject: [PATCH] readahead: do not increase nr_requests for root fs block |
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device |
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Having nr_requests can cause system lockups. Arguably, this should get |
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fixed somehow in kernel. For now we just stop changing the |
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value. |
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Note that not bumping a value may cause that posix_fadvise call |
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will block in case there is no room in a request queue. |
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See: http://article.gmane.org/gmane.linux.kernel/1072356 |
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RHEL-only |
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Resolves: #1314559 |
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--- |
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src/readahead/readahead-common.c | 64 -------------------------------- |
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src/readahead/readahead-common.h | 2 - |
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src/readahead/readahead-replay.c | 2 - |
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3 files changed, 68 deletions(-) |
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diff --git a/src/readahead/readahead-common.c b/src/readahead/readahead-common.c |
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index 3ca48a7257..6cf33f7cfe 100644 |
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--- a/src/readahead/readahead-common.c |
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+++ b/src/readahead/readahead-common.c |
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@@ -253,70 +253,6 @@ ReadaheadShared *shared_get(void) { |
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return m; |
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} |
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-/* We use 20K instead of the more human digestable 16K here. Why? |
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- Simply so that it is more unlikely that users end up picking this |
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- value too so that we can recognize better whether the user changed |
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- the value while we had it temporarily bumped. */ |
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-#define BUMP_REQUEST_NR (20*1024u) |
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- |
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-int block_bump_request_nr(const char *p) { |
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- struct stat st; |
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- uint64_t u; |
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- char *ap = NULL, *line = NULL; |
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- int r; |
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- dev_t d; |
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- |
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- assert(p); |
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- |
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- if (stat(p, &st) < 0) |
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- return -errno; |
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- |
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- if (major(st.st_dev) == 0) |
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- return 0; |
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- |
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- d = st.st_dev; |
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- block_get_whole_disk(d, &d); |
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- |
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- if (asprintf(&ap, "/sys/dev/block/%u:%u/queue/nr_requests", major(d), minor(d)) < 0) { |
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- r= -ENOMEM; |
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- goto finish; |
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- } |
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- |
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- r = read_one_line_file(ap, &line); |
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- if (r < 0) { |
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- if (r == -ENOENT) |
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- r = 0; |
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- goto finish; |
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- } |
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- |
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- r = safe_atou64(line, &u); |
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- if (r >= 0 && u >= BUMP_REQUEST_NR) { |
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- r = 0; |
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- goto finish; |
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- } |
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- |
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- free(line); |
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- line = NULL; |
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- |
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- if (asprintf(&line, "%u", BUMP_REQUEST_NR) < 0) { |
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- r = -ENOMEM; |
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- goto finish; |
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- } |
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- |
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- r = write_string_file(ap, line); |
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- if (r < 0) |
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- goto finish; |
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- |
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- log_info("Bumped block_nr parameter of %u:%u to %u. This is a temporary hack and should be removed one day.", major(d), minor(d), BUMP_REQUEST_NR); |
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- r = 1; |
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- |
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-finish: |
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- free(ap); |
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- free(line); |
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- |
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- return r; |
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-} |
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- |
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int block_get_readahead(const char *p, uint64_t *bytes) { |
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struct stat st; |
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char *ap = NULL, *line = NULL; |
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diff --git a/src/readahead/readahead-common.h b/src/readahead/readahead-common.h |
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index b34f3aadd7..cc2ea81a9d 100644 |
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--- a/src/readahead/readahead-common.h |
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+++ b/src/readahead/readahead-common.h |
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@@ -51,8 +51,6 @@ typedef struct ReadaheadShared { |
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ReadaheadShared *shared_get(void); |
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-int block_bump_request_nr(const char *p); |
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- |
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int block_get_readahead(const char *p, uint64_t *bytes); |
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int block_set_readahead(const char *p, uint64_t bytes); |
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diff --git a/src/readahead/readahead-replay.c b/src/readahead/readahead-replay.c |
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index f81e0fe55d..c2e281687a 100644 |
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--- a/src/readahead/readahead-replay.c |
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+++ b/src/readahead/readahead-replay.c |
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@@ -134,8 +134,6 @@ static int replay(const char *root) { |
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assert(root); |
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- block_bump_request_nr(root); |
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- |
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if (asprintf(&pack_fn, "%s/.readahead", root) < 0) |
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return log_oom(); |
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